Fix for slow SD card speed with HTC's Froyo Kernel

[frankoid]

There have been quite a few complaints about slow SD card speeds with Froyo/Sense ROMs (e.g. http://forum.xda-developers.com/showthread.php?t=778748).

I've looked into the problem and discovered that the poor performance is due to HTC reducing the readahead settings in their kernel.

I've attached a prebuilt kernel (as a flashable zip using Koush's AnyKernel) and a kernel source patch that fix this. Let me know how you get on

EDIT: if you prefer Richardtrip's kernel to the stock one, use the update zip here, or v5 or later of his kernel, instead of kernel_2.6.32-frankoid.zip

To see whether your kernel needs the fix you need to run a command with your phone plugged in to your computer. On Linux and OS X you need to include quotes, like this:

adb shell 'cat /sys/devices/virtual/bdi/179:0/read_ahead_kb'

If you are using Windows don't include the quotes - run this:

adb shell cat /sys/devices/virtual/bdi/179:0/read_ahead_kb

If it returns 4 then you need the fix. If it returns 128 you don't need it.

If you are a developer and you'd like to incorporate this fix into your ROM without having to change the kernel see this post for instructions on how to edit init.rc to change the readahead setting.

 

[hensk]

only for SENCE

 

[frankoid]

only for SENCE

Yes, this is only for Sense, but I haven't had any problem with SD card speeds on non-Sense ROMs.

 

[elmalote]

Will flashing this remove OC? I'm running Richards kernel and not stock. Will your zip file overwrite?

Sent from my HTC Desire

 

[frankoid]

Will flashing this remove OC? I'm running Richards kernel and not stock. Will your zip file overwrite?

I'm not sure, I don't overclock myself. I have turned off perflock in this kernel though so it might work.

You could always give it a try and restore a nandroid backup if you lose OC.

The best thing in the long run would probably be to ask Richard to apply the patch to his kernel.

 

[LoQo_]

Don't works on rcmixhd v10. I flash it and not reboot well

Sent from my HTC Desire using Tapatalk

 

[Audioboxer]

Will flashing this remove OC? I'm running Richards kernel and not stock. Will your zip file overwrite?

Sent from my HTC Desire

Want to know this as well, but if you've fixed the problem my hat off to you sir! It really annoys me.

 

[eViL D:]

Nice, gonna check it out. Do you have any statistics?

*edit, this has already been pushed upstream to .35+ kernels.

 

[harish.awe]

Not working in RcmixHD..!!!

In which ROM did you try OP..??

 

[dennis.l]

Not working in RcmixHD..!!!

In which ROM did you try OP..??

RCmixHD is the rom port from the desire HD isn't it?

 

[bobbenedetti]

I installed it on a Telus HTC Desire SLCD with LeeDroid 2.2d and tested it on a class 10 card with SD Speed Card Test..My write speed remained at the 2MB/s it showed before (same on a Class 6 and Class 2 card) but the read speed jumped to 13MB/s.
Any thoughts why the write speed didn't show the same increase as read?
Good start I love the increased read speed..it would be nice to see a similar increase in writing..

Good work

 

[hamdir]

Is the speed jump only in storage mode?

 

[hover99]

Wow many great thanks !!!

Before:
Write 4 mb/s
Read 6 mb/s

After:
Write 4 mb/s
Read 13 mb/s

On my PC i have a read speed around 19 mb/s, but 13 mb/s is fabulous enough, more write speed would be nice, but i 4 mb/s is ok for the moment..

Im using this ROM: http://forum.xda-developers.com/showthread.php?t=773997
so this should work on every Froyo Sense ROM

PS: the gallery is now so f*** fast this is great ;-)

 

[Anakha56]

Anyone with Pays ROM tried this yet? Wondering if its needed with the latest Pays ROM...

 

[ivicask]

Hello frankoid , could you make us version for Sense HD roms, as lots of files there are puted on SD, this would make entire rom much faster!

 

[hamdir]

Wow many great thanks !!!

Before:
Write 4 mb/s
Read 6 mb/s

After:
Write 4 mb/s
Read 13 mb/s

On my PC i have a read speed around 19 mb/s, but 13 mb/s is fabulous enough, more write speed would be nice, but i 4 mb/s is ok for the moment..

Im using this ROM: http://forum.xda-developers.com/showthread.php?t=773997
so this should work on every Froyo Sense ROM

PS: the gallery is now so f*** fast this is great ;-)

do you richard's UVOC installed?

 

[hover99]

do you richard's UVOC installed?

No, close to stock, only the POWERSAVING MODPACK ..

 

[whvnx]

This kernel certainly will replace Richard's. Just tried it minutes ago. In the SetCPU, the max speed goes back to 998 Mhz instead of Richard's 1330 Mhz.

 

[frankoid]

Not working in RcmixHD..!!!

In which ROM did you try OP..??

I'm using my own ROM based on RUU_Bravo_Froy2_UK_2.14.207.1. This kernel should work on most Froyo/Sense ROMs that use the stock kernel. If your Sense ROM uses a custom kernel ask the ROM's developer to apply this patch. This patch is not necessary for non-Sense ROMs.

 

[frankoid]

Nice, gonna check it out. Do you have any statistics?

*edit, this has already been pushed upstream to .35+ kernels.

Which .35 kernel? I think that the change to reduce the readahead never made it into the Cyanogen & Teamdesire etc. kernels, so this patch to increase the readahead again isn't necessary for them.