Develop Bugs

Nexus Storage Performance Over Time & TRIM 20150508

Android 4.3 Update Brings TRIM to All Nexus Devices
The Android framework will send out a “start idle maintenance window” event that the MountService listens for, and then invokes vold to fstrim filesystems when a few conditions have been met – the device hasn’t been touched for over an hour, no idle maintenance window event has been sent in 24 hours, and the device is either off-charger with 80% battery or on-charger with 30% battery. The goal is to have fstrim run roughly once every 24 hours if you’re in the habit of plugging the device in to charge every night.
Click to expand...
Click to collapse
Finally Google, you hear us out! Thanks.
Great review from anandtech as always: #fstrim #trim #vold #android #nexus
http://www.anandtech.com/show/7185/android-43-update-brings-trim-to-all-nexus-devices
I really wish Google will also implement the Moto X's Flash Friendly File System aka f2fs on next version of Android to improve random write IOPS and overall system responsiveness.
http://www.anandtech.com/show/7235/moto-x-review/9
-------------
Dear All,
I've been curious after reading Anandtech articles regarding Asus Nexus 7 storage performance and how it compared to other Asus Tablet and Galaxy Nexus. Using Androbench app from Google Play as their tool, I managed to get the result of my Galaxy Nexus after it being used to watch tv series this last three week, and to my surprise, the performance was slowed down perhaps because all the capacity has been used and overwritten and thus having this write amplification effect on flash memory and ssd.
I don't know how to TRIM a eMMC storage on Galaxy Nexus, neither have the knowledge of app or tweak to TRIM, thus I reset to factory image since it formated six partition and restore each to a clean slate with the bootloader, radio, system, userdata, boot, and recovery images. So here's the result I found as per attached. The results were quite shocking though not so significant but it seemed the flashing of the images did restore the storage performance back to normal.
Now I wonder if Linux kernel on Android Jelly Bean supports or will support automatic trimming the eMMC in the near future so it will restore the eMMC (storage) write performance when idling, or is there a tool or adb command to trigger the TRIM command so we don't have to do the backup and restore when resetting to Google factory image?
Resources:
Anandtech: Exploring the Relationship Between Spare Area and Performance Consistency in Modern SSDs
Anandtech: Asus Nexus 7 Storage Performance
Anandtech: SSD Anthology
Anandtech: Performance Over Time and TRIM
Wikipedia: TRIM
Debian Linux SSD Optimization
Impact of ext4′s discard option on my SSD
Android on eMMC: Optimizing for Performance
LINARO: Intro to eMMC - Effectiveness of TRIM
I found bug reported on Android Open Source Project with Issues ID 37258. The screenshots of their Androbench app results were scary, reach below 1Mbps for sequential write (recall the USB1.1 performance?).
Please vote for this issues if you're having similar slow down experience after using your sdcard's capacity to the max. There are already more than 200 people vote for this issue. The more people vote the more chance AOSP developer would hear us out. To vote, click the star icon below add comment section on bottom of this following Android Open Source Issues page:
Nexus 7 Poor Write Speeds After Using Almost All Storage Capacity
Galaxy Nexus GSM Poor Write Speeds After Using Almost All Storage Capacity
Galaxy Nexus Storage Performance Over Time & TRIM
Current work around:
fifthelement said:
There is a much better app than lagfix to trim manually. free, ad-free with schedules and lollipop support : https://play.google.com/store/apps/details?id=com.fifthelement.trimmer
Click to expand...
Click to collapse
use AuxLV's LagFix (fstrim) app from Google Play weekly. (highly recommended) :good:
use backfromthestorm fstrim init.d to fstrim on each reboot flashed using CWM recovery, no crontab yet, but much appreciated. (highly recommended) :good:
use your storage wisely, keeping your free space available at 25% available or more to avoid significant slow write degradation. (highly recommended) :good:
return to stock or format /system, /data/, and /cache could help your eMMC storage performance back to normal. (recommended)
mounting the /data partition with discard option and secured erase the free space. (proceed with CAUTION since there's bug brick on some eMMC chip, you may want to check your eMMC chip first using "Got Brickbug ?" app by Chainfire.)
using kernel with fsync off. (NOT recommended)
Keeping your storage at 25% available will make the storage sub-system performance more consistent on SSD, I believe eMMC using same NAND chipset as in SSD less the controller.
Galaxy Nexus eMMC chip list:
VYL00M (insignificant effect)
V3U00M (significant effect)
My take on Galaxy Nexus 16GB storage performance (eMMC VYL00M rev. 0x25):
Return to stock factory image and filling up the storage with 4GB space available:
SW from 7.53MBps to 5.46MBps ~ 27% loss
RW from 0.24MBps to 0.22MBps ~ 8% loss
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"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
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"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Before and after filling up to 389MB space available:
SW from 7.53MBps to 3.91MBps ~ 48% loss
RW from 0.24MBps to 0.23MBps ~ 4% loss
Delete some files to make 4GB space available, and reboot:
SW from 3.91MBps to 6.96MBps ~ 78% gain
RW is the same on 0.23MBps ~ no gain/loss
My take on Nexus 4 16GB storage performance:
Before and after filling up the storage (coming from 5GB and filling it up to 1.2GB space available):
SW from 10 MBps to 4 MBps ~ 60% loss
RW from 1 MBps to 0.39 MBps ~ 61% loss
Did a reboot and the performance is getting better (1.2GB space available, deleted some files left with 2.2GB space available but the performance is more less the same):
SW from 4 MBps to 9.89 MBps ~ 147% gain
RW from 0.39 MBps to 0.51 MBps ~ 31% gain
Using the fstrim app (LagFix for Nexus 7 and HTC One X) and reboot (2.2GB space available):
SW from 9.89 MBps to 9.9 MBps ~ 0.1% gain
RW from 0.51 MBps to 1.07 MBps ~ 110% gain
I attached the cwm packages just for backups. Original scripts are written by backfromthestorm. :good:
Credits (notify me if I forgot to add you here):
ph4zrd
AuxLV
backfromthestrom
JPBeard21
markop90
alangrig
BrianDigital
---
quick thought on samsung eMMC brick bug and how fstrim prolong nand chipset lifespan:
the eMMC brick bug on samsung devices might be related with its own ssd department too. more info about this firmware bug in anandtech site here.
Earlier Samsung told us that all review samples including our three shipped with a pre-production firmware that had a bug in it causing the failures (retail units were shipped with a newer firmware without the bug). At the time we didn't know what exactly was wrong in the firmware, but now we do. When the drive was issued a secure erase command, it would clear all table mapping information at the Address Translation Layer (ATL) but not at the Host Interface Layer (HIL). The data in both layers needs to be up-to-date for the drive operate properly, so when a write request came in, the controller wasn't able to map the data correctly, which caused the firmware to hang. An SSD obviously can't operate without a functioning firmware so from a user's standpoint, it looked like the drive had completely died even though only its firmware was broken.
Click to expand...
Click to collapse
me myself often wonder how come almost all review sites told us to trim in order to prolong the nand chipset lifespan and improve performance. i think i finally found a link to confirm that trim/fstrim does improve nand chipset lifespan by reducing the write amplification.
without trim: storage is nearly full (used, free, and mark as deleted block), and you need to write a bunch of new files which exceed the free available block, the system must do this cycle: read the mark as deleted blocks, erase the mark as deleted blocks, modify the free available block, and write the new files.
with trim: storage is nearly full (used, trully free available), and you need to write a bunch of new files, the system just do this cycle: write the new files, hence less write amplification, longer lifespan and much faster write performance.
the trim command and secure erase are somehow very well explained in this write amplification article on wikipedia here.
TRIM is a SATA command that enables the operating system to tell an SSD what blocks of previously saved data are no longer needed as a result of file deletions or using the format command. When an LBA is replaced by the OS, as with an overwrite of a file, the SSD knows that the original LBA can be marked as stale or invalid and it will not save those blocks during garbage collection. If the user or operating system erases a file (not just remove parts of it), the file will typically be marked for deletion, but the actual contents on the disk are never actually erased. Because of this, the SSD does not know the LBAs that the file previously occupied can be erased, so the SSD will keep garbage collecting them.
The introduction of the TRIM command resolves this problem for operating systems which support it like Windows 7, Mac OS (latest releases of Snow Leopard, Lion, and Mountain Lion, patched in some cases), and Linux since 2.6.33. When a file is permanently deleted or the drive is formatted, the OS sends the TRIM command along with the LBAs that are no longer containing valid data. This informs the SSD that the LBAs in use can be erased and reused. This reduces the LBAs needing to be moved during garbage collection. The result is the SSD will have more free space enabling lower write amplification and higher performance.
The actual benefit of the TRIM command depends upon the free user space on the SSD. If the user capacity on the SSD was 100 GB and the user actually saved 95 GB of data to the drive, any TRIM operation would not add more than 5 GB of free space for garbage collection and wear leveling. In those situations, increasing the amount of over-provisioning by 5 GB would allow the SSD to have more consistent performance because it would always have the additional 5 GB of additional free space without having to wait for the TRIM command to come from the OS.
Click to expand...
Click to collapse
resources:
http://www.anandtech.com/show/6503/second-update-on-samsung-ssd-840840-pro-failures
http://en.wikipedia.org/wiki/TRIM
---
Factory reset via stock recovery, and then use LagFix app or cwm flashable fstrim for optimizing io performance:
AuxLV has made this wonderful app to fstrim your NAND/eMMC storage so it will restore the write performance back to normal after having slow down issues on sequential write and random write due to usage over time. Tested on Nexus 4 and it worked, yay! Do note that this app contains ads from doubleagent and admob as some reported on the original thread.
Take a look at AuxLV LagFix (fstrim) original thread here. AuxLV LagFix (fstrim) FAQs here.
There are two versions of LagFix:
LagFix (fstrim) Premium version - no ads + ability to auto-run trimming on specified schedule. The best choise!
LagFix (fstrim) Free version - trims your memory with one click, has ads, no schedule.
Click to expand...
Click to collapse
backfromthestorm also compiled a flashable script to do fstrim using CWM recovery. take a look at his post here or download the fstrim CWM packages as follows:
fstrim for /system, /data. and /cache here (works on Nexus 4 too!)
fstrim for /data and /cache here
fstrim on reboot here
It seems there's a typo inside the above fstrim init.d script. here's a fix from JPBeard21:
https://www.box.com/shared/l5afni1mxe1wpb2ubw3s

i'm wondering too
Sent from my Galaxy Nexus using xda app-developers app

My sequential write is down to 2.27mb/sec

Never reset my phone to stock and my numbers are all much better than yours. Using Faux kernel with FIOPS scheduler

Looks like someone has been changing ROMs without doing a factory reset...
Sent from my Nexus 7 using xda premium

Teezekel said:
Interesting
Click to expand...
Click to collapse
kizakiyuria said:
i'm wondering too
Sent from my Galaxy Nexus using xda app-developers app
Click to expand...
Click to collapse
Yeah, i never thought this would happen. Hehe
peachpuff said:
My sequential write is down to 2.27mb/sec
Click to expand...
Click to collapse
Whoa, did you frequent use your storage with lots of small and big file sizes?
I guess you do a lot of write-delete-write cycle like me. I get new hobby to watch 720p movies and hdtv series on this gnex, and total Bit written in my storage were over 16GB, hence the flash memory or nand's write amplication occured and slowed down both sequential and random write speed.
Sdobron said:
Never reset my phone to stock and my numbers are all much better than yours. Using Faux kernel with FIOPS scheduler
Click to expand...
Click to collapse
Now that is awesome! Stock kernel didn't have this tweak on storage performance. hope they will add this feature on next build.
Sent from my Galaxy Nexus

Soldier-2Point0 said:
Looks like someone has been changing ROMs without doing a factory reset...
Sent from my Nexus 7 using xda premium
Click to expand...
Click to collapse
I would point to how much free space is left rather than that wiping everytime a rom is changed....
Sent from my Nexus 7 using Tapatalk 2
---------- Post added at 05:28 AM ---------- Previous post was at 05:26 AM ----------
Sdobron said:
Never reset my phone to stock and my numbers are all much better than yours. Using Faux kernel with FIOPS scheduler
Click to expand...
Click to collapse
Is fsync turned off in faux?
Sent from my Nexus 7 using Tapatalk 2

BrianDigital said:
Is fsync turned off in faux?
Sent from my Nexus 7 using Tapatalk 2
Click to expand...
Click to collapse
Is fsync enabled by default on stock kernel? That explains the slow performance on write but with safer data.
Sent from my Galaxy Nexus

Disregard

There is absolutely no point at all in doing this. The increase is so small that its just a waste of time.
Sent from my Galaxy Nexus using xda app-developers app

chrone said:
Is fsync enabled by default on stock kernel? That explains the slow performance on write but with safer data.
Sent from my Galaxy Nexus
Click to expand...
Click to collapse
Yes it is enabled in stock setups, turning it off just leaves the stuff in ram it also tricks benchmarking tests with inaccurate data since its not doing the writing
To the op my stock gnex has results more akin to the after trim results how much storage do you have free
Sent from my Nexus 7 using Tapatalk 2

GldRush98 said:
First off, trim is a command, and more specifically an ATA command. It has nothing to do with eMMC storage. There is no such thing for eMMC.
Second off, eMMC doesn't really need to be trim'ed like SSD's do. The eMMC 4.5 spec did include a discard sub-operation, but it is really not beneficial, especially on our low storage capacity mobile devices.
Click to expand...
Click to collapse
thanks for the heads up. unfortunately a lot of nexus 7 users report slow performance once their sdcard was fulled with data and the regression was pretty much down to below 1Mbps for sequential write. take a look the bugs reported on android open source project.
Smokeey said:
There is absolutely no point at all in doing this. The increase is so small that its just a waste of time.
Sent from my Galaxy Nexus using xda app-developers app
Click to expand...
Click to collapse
same as the above.
BrianDigital said:
Yes it is enabled in stock setups, turning it off just leaves the stuff in ram it also tricks benchmarking tests with inaccurate data since its not doing the writing
To the op my stock gnex has results more akin to the after trim results how much storage do you have free
Sent from my Nexus 7 using Tapatalk 2
Click to expand...
Click to collapse
oh okay, nice to know that.
the available storage left around 3-5gb i guess?
forgot to check when it's down to 5Mbps sequential write. i watched supernatural season 1 to season 6 using gnex before reset to factory image, and the total amount of the serial was more less 42Gb, thus frequent copy-watch-delete thing.
care to vote for bug fix on android open source project as follows? more than 200 people voted this bug to be fix or this feature to be implemented. hope google will listen.
the bug report link, to vote on this following link, click the star button below add comment section at bottom of adroind open source project but report page:
https://code.google.com/p/android/issues/detail?id=37258

Same issue here... If my free space goes below 3gb the phone begins to slow down horribly... Until I factory-reset it....
Random writes <0.50 mb/s on androbench

BrianDigital said:
I would point to how much free space is left rather than that wiping everytime a rom is changed....
Sent from my Nexus 7 using Tapatalk 2
---------- Post added at 05:28 AM ---------- Previous post was at 05:26 AM ----------
Is fsync turned off in faux?
Sent from my Nexus 7 using Tapatalk 2
Click to expand...
Click to collapse
I'm pretty sure I recall reading it's off but I'm not 100% sure...

I usually have about 1 or 2 movies (~700MB or ~1.6GB) on my phone at a time and never had any problems. One day, I felt ambitious to watch a few movies and pretty much got my GNex to under 3GB. Since then, it hasn't been the same.
What I have
GSM Galaxy Nexus
yakjuxw
4.1.1 stock
Unlocked and Rooted
Baseband version I9250XXLF1
Kernel Version 3.0.31-g6fb96c9
Build Number JRO03C.I9250XWLH2
What I've tried
Clearing up movies, camera pictures/videos
Uninstalling recent apps
Clearing app/browser caches
AndroBench Results with 8.14GB available
Sequential Read = 1.97 MB/s
Sequential Write = 0.14 MB/s
Random Read = 0.39 MB/s, 101.47 IOPS(4K)
Random Write = 0.0 MB/s, 1.76 IOPS(4K)
EDIT: Converted from Yakjuxw to yakju using this and now running stock 4.1.2. Now my AndroBench is
26.93 MB/s
12.21 MB/s
8.98 MB/s
0.52 MB/s

markop90 said:
Same issue here... If my free space goes below 3gb the phone begins to slow down horribly... Until I factory-reset it....
Random writes <0.50 mb/s on androbench
Click to expand...
Click to collapse
zero_x3 said:
I usually have about 1 or 2 movies (~700MB or ~1.6GB) on my phone at a time and never had any problems. One day, I felt ambitious to watch a few movies and pretty much got my GNex to under 3GB. Since then, it hasn't been the same.
What I have
GSM Galaxy Nexus
yakjuxw
4.1.1 stock
Unlocked and Rooted
Baseband version I9250XXLF1
Kernel Version 3.0.31-g6fb96c9
Build Number JRO03C.I9250XWLH2
What I've tried
Clearing up movies, camera pictures/videos
Uninstalling recent apps
Clearing app/browser caches
AndroBench Results with 8.14GB available
Sequential Read = 1.97 MB/s
Sequential Write = 0.14 MB/s
Random Read = 0.39 MB/s, 101.47 IOPS(4K)
Random Write = 0.0 MB/s, 1.76 IOPS(4K)
This last AndroBench test is just horrible.
Click to expand...
Click to collapse
same boat here. reset to factory image does format the sdcard and the performance is back to normal again. i hope they do fix this on next build to trigger a command something like TRIM on SSD without having the need to reset to factory image periodically. please vote at the bottom page of page one for Android dev to hear us out regarding this problem. this happens on Nexus 7 as well.

Mounting the relevant partitions with ext4's discard option (as I suggested on code.google.com/p/android/issues/detail?id=39154) seems to fix the problem. You may then fill the filesystem with zeros using dd and simply delete the created file afterwards.

How do you guys regard these results?:
Sent from my Galaxy Nexus using xda premium

I had this problem, and remounting data and cache with discard option on every boot solved this.

alangrig said:
How do you guys regard these results?:
Sent from my Galaxy Nexus using xda premium
Click to expand...
Click to collapse
It's normal.
When your sequential write speed is way below 7MBps then something is not right. The random write will be affected too.
Sent from my Galaxy Nexus

Disabling CPU Rendering (?)

Just flashed a new ROM today (OneOfAKindV11 by ipromeh) and gaming works really smooth even when its clocked at 1.6GHz... I heard Disabling CPU Rendering will make gaming more faster... Last time, when i tried it, game lags alot and overall performance is bad...
Can anyone tell me if the tweak is good or not?

Maybe it's good disabling CPU Rendering on newest CPU with newest GPU...But our GPU needs an additional support from the CPU

So its not good to disable it even with cm10 alpha 7? Just leave it as is?
Sent from my GT-I8150 using xda premium

Disabling CPU rendering diables the CPU rendering for the User Interface and forces the GPU to do it. So it affects the launcher, browser and scrolling but not games. For JB it´s not needed because of project butter which makes it already smooth.
JB also dosen´t use the exact same drivers like ICS, so what gives you a performance boost in CM9 doesn´t have to do the same in CM10.

I install seeder for disable CPU rendering... But I have problem with flash when I see flash video (ex: youtube)...

arya_ruby said:
I install seeder for disable CPU rendering... But I have problem with flash when I see flash video (ex: youtube)...
Click to expand...
Click to collapse
That´s interessting.... does the problem disappear if you re-enable CPU rendering? Also are you using CM9 or CM10?
For me there is no problem in watching youtube after disabling CPU rendering in CM9, but must agree that in both ROMs some flash videos are not displayed correctly. This is more related to the GPU drivers in CM9 and CM10 and the missing flash support in ICS and JB.
There are sites where the flash videos are not displayed correctly in CM9 and CM10, no matter you disable CPU rendering or not, but at least youtube is working well in CM9 after disabling CPU rendering. Can´t tell how about CM10, but CM10 needs both for project butter to work.

honeyx said:
That´s interessting.... does the problem disappear if you re-enable CPU rendering? Also are you using CM9 or CM10?
For me there is no problem in watching youtube after disabling CPU rendering in CM9, but must agree that in both ROMs some flash videos are not displayed correctly. This is more related to the GPU drivers in CM9 and CM10 and the missing flash support in ICS and JB.
There are sites where the flash videos are not displayed correctly in CM9 and CM10, no matter you disable CPU rendering or not, but at least youtube is working well in CM9 after disabling CPU rendering. Can´t tell how about CM10, but CM10 needs both for project butter to work.
Click to expand...
Click to collapse
I running CM10. And I was disable it, but I can't find the different.
Thanks for help me.

arya_ruby said:
I install seeder for disable CPU rendering... But I have problem with flash when I see flash video (ex: youtube)...
Click to expand...
Click to collapse
Seeder is *NOT* for disabling CPU rendering.
--- Sent from Opera on Lenovo T420 ---

pepoluan said:
Seeder is *NOT* for disabling CPU rendering.
--- Sent from Opera on Lenovo T420 ---
Click to expand...
Click to collapse
True dat...
Too much flashing! I'm blinded on my Galaxy W!

pepoluan said:
Seeder is *NOT* for disabling CPU rendering.
--- Sent from Opera on Lenovo T420 ---
Click to expand...
Click to collapse
Ohhh. Thanks for clarify this. Never dealed with seeder so am not aware atm what it is for.
So if someone is saying it disabled CPU rendering as well, I take this information as to be true.
@arya_ruby: Your postings are very irritating. In the one hand your a claiming seeders is disabling CPU rendering and this is causing problems with youtube, in the other hand you are saying you disabled it but can´t (find?) (or see) a difference.
So what?
First you should inform what seeder is for and what´s doing on your phone before making conflicting claims.

honeyx said:
Ohhh. Thanks for clarify this. Never dealed with seeder so am not aware atm what it is for.
So if someone is saying it disabled CPU rendering as well, I take this information as to be true.
@arya_ruby: Your postings are very irritating. In the one hand your a claiming seeders is disabling CPU rendering and this is causing problems with youtube, in the other hand you are saying you disabled it but can´t (find?) (or see) a difference.
So what?
First you should inform what seeder is for and what´s doing on your phone before making conflicting claims.
Click to expand...
Click to collapse
Since I was slightly involved in the development of Seeder, let me give some information:
Seeder's purpose is to quickly fill up the entropy pool used by /dev/random and /dev/urandom. If this pool gets empty, lags will happen as the kernel interrupts things (including, blocking multithreading temporarily) to fill up the pool. With Seeder running, it periodically fills up the pool to prevent it from ever draining completely.
Some people swear that installing Seeder makes their phones run smoother, because the kernel never has to trigger 'urgent refilling', which as I mentioned before, temporarily disables multithreading.
However, things learnt during the (sometimes heated) discussion about how Seeder does its magic, undoubtedly have trickled down to kernel makers; many have identified the possible bottlenecks where lags happen, and many actively took steps to prevent such situation from happening. Thus, as time goes by, the improvement Seeder brought originally gets less and less significant, even to the point that it's no longer perceptible.
Sent from my GT-I8150 using xda app-developers app

pepoluan said:
Since I was slightly involved in the development of Seeder, let me give some information:
Seeder's purpose is to quickly fill up the entropy pool used by /dev/random and /dev/urandom. If this pool gets empty, lags will happen as the kernel interrupts things (including, blocking multithreading temporarily) to fill up the pool. With Seeder running, it periodically fills up the pool to prevent it from ever draining completely.
Some people swear that installing Seeder makes their phones run smoother, because the kernel never has to trigger 'urgent refilling', which as I mentioned before, temporarily disables multithreading.
However, things learnt during the (sometimes heated) discussion about how Seeder does its magic, undoubtedly have trickled down to kernel makers; many have identified the possible bottlenecks where lags happen, and many actively took steps to prevent such situation from happening. Thus, as time goes by, the improvement Seeder brought originally gets less and less significant, even to the point that it's no longer perceptible.
Sent from my GT-I8150 using xda app-developers app
Click to expand...
Click to collapse
Sadly, some using Seeders... Some use crossbreeder... Its the same rite?
Too much flashing! I'm blinded on my Galaxy W!

TiTAN-O-One said:
Sadly, some using Seeders... Some use crossbreeder... Its the same rite?
Too much flashing! I'm blinded on my Galaxy W!
Click to expand...
Click to collapse
Kinda similar...
Seeder uses rngd, which uses a PRNG.
Crossbreeder uses haveged, which uses a CSPRNG based on a multitude of CPU counters.
From a security point of view, haveged is more secure than rngd. But I can find no way to tune haveged's parameters, so I can't be sure that it won't be triggered at inopportune times.
rngd, OTOH, is much more tunable; the flashable-zip available in the Seeder thread has been tuned by me and @ryuinferno to be less intrusive.
(Just in case anyone is wondering: we had tuned rngd's nice value so it yields to higher-priority processes, tuned its cycle period so that it won't get triggered too frequently, tuned its 'high watermark' to make it return faster, and so on).
Sent from my GT-I8150 using xda app-developers app

pepoluan said:
Kinda similar...
Seeder uses rngd, which uses a PRNG.
Crossbreeder uses haveged, which uses a CSPRNG based on a multitude of CPU counters.
From a security point of view, haveged is more secure than rngd. But I can find no way to tune haveged's parameters, so I can't be sure that it won't be triggered at inopportune times.
rngd, OTOH, is much more tunable; the flashable-zip available in the Seeder thread has been tuned by me and @ryuinferno to be less intrusive.
(Just in case anyone is wondering: we had tuned rngd's nice value so it yields to higher-priority processes, tuned its cycle period so that it won't get triggered too frequently, tuned its 'high watermark' to make it return faster, and so on).
Sent from my GT-I8150 using xda app-developers app
Click to expand...
Click to collapse
But Seeders will Conflict with Crossbreeder rite? I thought its 2 separate tweaks so that we can use both and have NO lags at all ^~^
Too much flashing! I'm blinded on my Galaxy W!

TiTAN-O-One said:
But Seeders will Conflict with Crossbreeder rite? I thought its 2 separate tweaks so that we can use both and have NO lags at all ^~^
Too much flashing! I'm blinded on my Galaxy W!
Click to expand...
Click to collapse
Not conflict, but since both will fill the same entropy pool, why install both and consume valuable RAM and CPU cycles?
There are *no* other purpose of rngd and haveged.
That said, Crossbreeder is not just haveged; there are other tunings that Crossbreeder does in addition to haveged.
Sent from my GT-I8150 using xda app-developers app

High CPU usage on IO requests

Sprint Galaxy Nexus with CyanogenMod and Franco.kernel. The phone slows to a crawl on many IO requests and I'm not sure why. I tried both row and CFQ and while row is sometimes better about it often times it will be unusable for minutes at a time. I tried to record a video yesterday and the moment I clicked record, my phone froze for 10 minutes and didn't return to normal until I managed to close the camera app. It also happens a lot on chrome, next browser, and stock browser. Are there any utilities to check the storage for errors
Sent from my Galaxy Nexus using xda app-developers app

I just did a benchmark with AndroBench and my random write is a whopping 0.16MB/s and sequential write is 5.15MB/s with the ROW scheduler
Did another benchmark after changing to CFQ scheduler and Random Write was 0.15MB/s so no real change, sequential write was 4.98
This was all after doing an fstrim which I heard was supposed to help solve these problems, but I don't have benchmarks from before, oh and I have 18GB free

i had these lags as well, turned out my device did not like francos kernel at all.
and i think i needed a full wipe since franco has some leftovers that dont get removed when flashimg other kernels.
also had to do it with roanager and not twrp... maybe you have the 2nd device that does not like francos kernel....
Sent from my Galaxy Nexus using XDA Premium 4 mobile app

[Q] Improving Performance?

Just curious if anyone else is getting extremely slow performance? I'm running CM10.1 and it is slow -- one of the last stable builds.
I've found that I can't have Hangouts + Facebook or Hangouts + Chrome open at the same time. It'll take ages to load something, so I end up having to force close everything pretty often. And my phone's battery is getting worse and worse in terms of performance
Have been debating what the cause could be. I have a TON of music on my external_sd -- wondering if maybe Android is constantly scanning it and it's slow/losing battery from that. The media scanning icon is not up, though. Could be the ROM? Have been debating dropping back to using a deodexed/debloated stock ROM. Wondering if maybe the battery is just naturally degrading -- I've had the phone for ALMOST one year. Wondering if it's the issue with just having 1GB of RAM on the device?
Any thoughts from anyone on improving performance? I would love to be able to go to work without having to charge the phone. I can go for about 8 hours at work (sometimes listening to music, sometimes not) and by the time I'm home, my phone is anywhere from 10-20%.

terinfire said:
Just curious if anyone else is getting extremely slow performance? I'm running CM10.1 and it is slow -- one of the last stable builds.
I've found that I can't have Hangouts + Facebook or Hangouts + Chrome open at the same time. It'll take ages to load something, so I end up having to force close everything pretty often. And my phone's battery is getting worse and worse in terms of performance
Have been debating what the cause could be. I have a TON of music on my external_sd -- wondering if maybe Android is constantly scanning it and it's slow/losing battery from that. The media scanning icon is not up, though. Could be the ROM? Have been debating dropping back to using a deodexed/debloated stock ROM. Wondering if maybe the battery is just naturally degrading -- I've had the phone for ALMOST one year. Wondering if it's the issue with just having 1GB of RAM on the device?
Any thoughts from anyone on improving performance? I would love to be able to go to work without having to charge the phone. I can go for about 8 hours at work (sometimes listening to music, sometimes not) and by the time I'm home, my phone is anywhere from 10-20%.
Click to expand...
Click to collapse
as I know media scan only runs after boot.
Most of android devices has less then 1 giga ram, I don think you need more. You can enable comcache. settings -> performance -> memory management -> zram , it needs kernel support.
zram compresses memory.
My 4.3 roms dont have zram support.
Factory reset always win. You should try latest cm10.2, I think 4.3 faster.

bubor said:
My 4.3 roms dont have zram support.
Factory reset always win. You should try latest cm10.2, I think 4.3 faster.
Click to expand...
Click to collapse
Wait, so the newest pacman doesn't have zram support? Is in the settings though.
Sent from my SGH-I927 using XDA Premium 4 mobile app

LaizureBoy said:
Wait, so the newest pacman doesn't have zram support? Is in the settings though.
Sent from my SGH-I927 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
kernel doesnt have zram.

Zram and other improvements
Hello, good afternoon to all
First, sorry to revive an old post, but i can't post in dev zone.
I am currently improving the performance of my i927.
I installed the kernel "LiteKernel" (V4.0-20130113 ICS) but I have some doubts. For example, how I can enable zram? How I can make a small OC the GPU?
I would appreciate some more advice.
Stock ICS 4.0.4 ROM UCLJ3 with LiteKernel ICS V4.0-20130113
Thanks a lot!

Try with trickster mod
Sent from my SGH-I927 using xda premium

Androide3 said:
Try with trickster mod
Sent from my SGH-I927 using xda premium
Click to expand...
Click to collapse
Thanks a lot!
zRam activated and working, and see that GPU is on 400mHz always
But i was thinking in app like Android Tuner that can set a boot profile... because i have to enable zRam every boot
Any idea? any other improvement?
THANKS!
EDIT: Now i see the option that i can set a profile when boot with trickster mod!! thanks again!

Performance Improvement

Let me introduce myself first. I have been developing software for Windows for almost 20 years. I love to tweak and tinker. That is what drew me to the Android platform. With that said, here are my findings:
I own a T989. I love the phone. I have tried numerous tweaks and scripts etc out there. In the end I found some very minor tweaks that I have done manually that make a noticeable difference in performance and a battery life.
The biggest increase in performance and battery life that I had noticed was going from a stock rom to CM 10. I am currently on CM 10.2 (and eagerly awaiting a stable version of CM 11).
With that said I noticed that if I changed just a few minor things CM 10.2 runs considerably faster.
Here is what I have done:
1. Disabled ZRAM completely. I have noticed that my phone boots faster with it disabled. I noticed that multitasking was not as good with it disabled but the phone seemed much snappier.
2. Changed Min Free values. I used the Performance Control app for this. My settings are currently as follows:
Foreground Applications: 16 mb
Visible Applications 18 mb
Secondary Server: 23 mb
Hidden Applications 42 mb
Content Providers 49 mb
Empty Applications 56 mb
This seemed to help a lot with multitasking and now it multitasks fast and the phone is much snappier and less laggy. So far my phone is very stable and fast.
3. Set SD Card Read Ahead to 2048.
4. I also left KSM disabled and left Allow purging of assets disabled.
That's it. My phone is rock solid stable and fast with these settings. I also noticed that my battery lasts about 15% longer. Even better than just switching to CyanogenMod 10.2 alone.
Let me know if it works for you.

I would absolutely love to try this, but I don't understand majority of what you wrote. I'm familiar with cyan though..
Sent from my SGH-T989 using xda premium

What is it that you don't understand? Maybe I can help.
Sent from my SAMSUNG-SGH-T989 using XDA Premium 4 mobile app

Here http://forum.xda-developers.com/showthread.php?t=2401988
*MEGA 4.4.2*GS2 4.4.2*2SHAYNEZ*
---------- Post added at 06:51 AM ---------- Previous post was at 06:48 AM ----------
How do you disable zram entirely is what I'm wondering ?
*MEGA 4.4.2*GS2 4.4.2*2SHAYNEZ*

Disabling ZRAM is CM is easy. Under the performance menu just go to Memory Management > ZRAM. Select Disable. Reboot.

Oh I'm running slimkat on my i9205 mega and downloaded the performance apk. And I'm running beanstalk on my t989
*MEGA 4.4.2*GS2 4.4.2*2SHAYNEZ*

I updated the OP with new Min Free settings. I noticed that it wasn't as stable as I thought. After using it heavily all day I updated some apps in the Play Store and the launcher hung and everything was slow until I rebooted.
I then changed it to the new values above and used it very heavily. I made sure at least 18 apps were open then reinstalled those same apps from the Play Store (I uninstalled them first). So far no problems.

Moderator: Please delete this post. I accidentally double posted.

Is there a way to disable ZRAM on a rooted stock T989 running 4.1.2?
Thanks in advance,
rabilancia

As far as I know the stock ROM doesn't have ZRAM.
Sent from my SAMSUNG-SGH-T989 using XDA Premium 4 mobile app

waresoft said:
As far as I know the stock ROM doesn't have ZRAM.
Sent from my SAMSUNG-SGH-T989 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
Try this then then me??
MR.GALAXY S²

waresoft said:
Let me introduce myself first. I have been developing software for Windows for almost 20 years. I love to tweak and tinker. That is what drew me to the Android platform. With that said, here are my findings:
I own a T989. I love the phone. I have tried numerous tweaks and scripts etc out there. In the end I found some very minor tweaks that I have done manually that make a noticeable difference in performance and a battery life.
The biggest increase in performance and battery life that I had noticed was going from a stock rom to CM 10. I am currently on CM 10.2 (and eagerly awaiting a stable version of CM 11).
With that said I noticed that if I changed just a few minor things CM 10.2 runs considerably faster.
Here is what I have done:
1. Disabled ZRAM completely. I have noticed that my phone boots faster with it disabled. I noticed that multitasking was not as good with it disabled but the phone seemed much snappier.
2. Changed Min Free values. I used the Performance Control app for this. My settings are currently as follows:
Foreground Applications: 16 mb
Visible Applications 18 mb
Secondary Server: 23 mb
Hidden Applications 42 mb
Content Providers 49 mb
Empty Applications 56 mb
This seemed to help a lot with multitasking and now it multitasks fast and the phone is much snappier and less laggy. So far my phone is very stable and fast.
3. Set SD Card Read Ahead to 2048.
4. I also left KSM disabled and left Allow purging of assets disabled.
That's it. My phone is rock solid stable and fast with these settings. I also noticed that my battery lasts about 7% longer. Even better than just switching to CyanogenMod 10.2 alone.
Let me know if it works for you.
Click to expand...
Click to collapse
Running JMT8 right now, and this has been one of the best posts I've seen on this forum. All roms I ever flashed would be snappy for the first couple days then slow to a crawl after a month. This has brought this phone back to life and prevent me from having to flash all the time. I wasn't able to do the ZRAM disable since I don't think I have that settings, but I updated the min-free settings and have seen noticable improvements. Thanks!

waresoft said:
1. Disabled ZRAM completely. I have noticed that my phone boots faster with it disabled. I noticed that multitasking was not as good with it disabled but the phone seemed much snappier.
Click to expand...
Click to collapse
Thank you so much! My lag is completely gone after disabling zram.

urBMidol said:
http://forum.xda-developers.com/showthread.php?t=2411161 flash this n be oh so happy ???
MR.GALAXY S²
Click to expand...
Click to collapse
What does this do exactly?

Will SD Card Read Ahead 2048 not reduce the life of the SD? (and by a lot since my current ROM was 200% less.)
Sent from my SAMSUNG-SGH-T989 using XDA Premium 4 mobile app

Zram has been disabled in the latest night lies just a fyi
Sent from my SAMSUNG-SGH-I727 using xda app-developers app

bobiscool07 said:
Will SD Card Read Ahead 2048 not reduce the life of the SD? (and by a lot since my current ROM was 200% less.)
Sent from my SAMSUNG-SGH-T989 using XDA Premium 4 mobile app
Click to expand...
Click to collapse
No. In writing a lot over time can possibly reduce the life of the SD. I don't believe that reading will.

waresoft said:
No. In writing a lot over time can possibly reduce the life of the SD. I don't believe that reading will.
Click to expand...
Click to collapse
I been rokcN 4096 n my exSD is cool I guess is there a way to test it
HERCULES S²

hatememarkz said:
I been rokcN 4096 n my exSD is cool I guess is there a way to test it
HERCULES S²
Click to expand...
Click to collapse
I use ROM Toolbox to benchmark. 2048 usually yields better results overall.
https://play.google.com/store/apps/details?id=com.jrummy.liberty.toolbox

waresoft said:
I use ROM Toolbox to benchmark. 2048 usually yields better results overall.
https://play.google.com/store/apps/details?id=com.jrummy.liberty.toolbox
Click to expand...
Click to collapse
Bro got that not a noob u tried okj yet
HERCULES S²