cancel
Showing results for 
Search instead for 
Did you mean: 

Archives Discussions

haydent
Journeyman III

Bug- 100% CPU usage when >1 GPU installed & used

normally: 1 gpu installed & used = 1% cpu usage

This is very commonly talked about so its not just me and you likely already know about it.

during opencl activity (btc mining) when i had 1 card installed (6950) i would get 1% cpu usage, but now i have 2 installed i get 100% cpu usage on the core i set their affinity to.

i had the same problem with various driver and sdk versions not being able to fix it.

it creates alot of extra heat and power usage for apparently no good reason as the cpu shouldnt be used at all....

we really appreciate the flash video lockup fix in 11.7, that was very annoying.

a fix to this also would be the last widespread problem ive heard of...

 

0 Likes
60 Replies
haydent
Journeyman III

here are a selection of threads discussing the issue:

http://forum.bitcoin.org/?topic=6188.0

http://forum.bitcoin.org/index.php?topic=6948.0

http://forum.bitcoin.org/?topic=4446.0

http://forum.bitcoin.org/index.php?topic=5954.0

http://forum.bitcoin.org/index.php?topic=26605.0

http://forum.bitcoin.org/index.php?topic=7991.0

http://forum.bitcoin.org/index.php?topic=27322.0

http://forum.bitcoin.org/index.php?topic=17767.0

http://forum.bitcoin.org/index.php?topic=18719.0

http://forum.bitcoin.org/index.php?topic=24786.0

http://forum.bitcoin.org/index.php?topic=19951.0

http://forum.bitcoin.org/index.php?topic=30818.new#new

0 Likes
simonk83
Journeyman III

Signed up to add my support for this.  Very annoying bug that we were all hoping would be fixed with 11.7.  Unfortunately not (and neither in 11.8, so far at least).

If this could be looked at that would be great.


Thanks.

0 Likes

I too faced this problem. The programs are written in OpenCL to use ONLY GPU's. But besides GPU's the programs also uses some CPU. The CPU usage varies from 10% to even some times 100%. This is really annoying as CPU getting used, it doesn't allow other programs, background programs to work properly. Besides why should a program written in OpenCL to use ONLY GPU use CPU also?

OpenCL development team took this matter serious & give some solution to reduce CPU usage to 0

0 Likes

I can confirm that with a 6950 on win7 x64, using Catalyst 11.7 or 11.8 preview, I get 100% cpu usage on any OpenCL app. Not just bitcoin, but OCLHashCat and ighashgpu as well.

When using 11.6, the cpu usage is as minimal as it needs to be. But, 11.6 still has the UVD crash bug.

0 Likes

i can also confirm this bug. i tried with oclHashcat-lite and the SDK example programs on ubuntu linux, 64 bit. with catalyst 11.6 i had 0% cpu load while with catalyst 11.7 i have 100% cpu load.

0 Likes

Thanks for reporting this, this is a known issue with multi-gpu configurations and we are working on a solution.
0 Likes

sorry, but let me correct this. it is not a multi-gpu problem. it is a general problem.

and the base of the problem is the gpu synchronization. for example, the command clFinish() which is used for wait till all commands in the queue are finished is told to be blocking and thereby creating 0% cpu.

and this worked fine on linux till cat 11.7. means with 11.6 and older it works and with 11.7 the behavior is more like now its doing a cpu burning loop to wait for the commands finish.

on windows its diffrent. the cat 11.7 behavior was seen since some time. with cat 11.6 it already was present and i guess some older versions, too. but i remember some time in 2010 (cat 10.x) where it worked good.

if you want to reproduce (this works on a single gpu as well):

on linux: install cat 11.6 and SDK 2.4, download oclHashcat-lite, run the example script and watch cpu activity -> 0%

now switch to cat 11.7. cpu activity -> 100%

0 Likes

Originally posted by: MicahVillmow Thanks for reporting this, this is a known issue with multi-gpu configurations and we are working on a solution.


 

this is very good to hear, thankyou for the news. 🙂

0 Likes

Originally posted by: MicahVillmow Thanks for reporting this, this is a known issue with multi-gpu configurations and we are working on a solution.


By that, do you mean that it's a bug in multi-gpu configuration that affect single gpu configuration? Because I get the bug with a single gpu.

When can we expect this problem fixed? Is it a far cry for it to be fixed in the final 11.8 (the UVD fix came a month earlier than estimated)?

0 Likes

Originally posted by: rorirub
Originally posted by: MicahVillmow Thanks for reporting this, this is a known issue with multi-gpu configurations and we are working on a solution.


 

By that, do you mean that it's a bug in multi-gpu configuration that affect single gpu configuration? Because I get the bug with a single gpu.

 

When can we expect this problem fixed? Is it a far cry for it to be fixed in the final 11.8 (the UVD fix came a month earlier than estimated)?

 

 

That'd be ideal.  Fingers crossed it's a priority.

0 Likes

The August 8 Catalyst 11.8 previews don't have the bug fixed yet.

0 Likes

11.8 final also has this bug. When can we expect a fix?

0 Likes

Originally posted by: rorirub 11.8 final also has this bug. When can we expect a fix?

 

I could not tell you the time lines of fix. Please see release notes of driver whether it is fixed or not.

0 Likes

Hello,

Just wanted to let you know - you might want to look inside of the problem - it is related (according to one of the OpenCL devs) :

Infinite number of sched_yield() calls to keep the cpu busy for a hot return back to the GPU. While this potentially can yield speed-ups through all sorts of means (during gaming for example), in mining it just chews up power and doesn't increase the hash rate in my testing.

 

And this is also ported to Linux - older 11.6 drivers are ok -> 11.7 / 11.8 = high CPU usage.

0 Likes

Seeing the same issue.

With drivers 11.7 and 11.8 with one or mutliple gpu, computations on gpu also take 100% use of cpu.

With drivers 11.6, the cpu is not used, but opencl only detects a single gpu.

0 Likes

Seeing the same issue with gentoo-x86_64. 11.6 froze the x server about once per day (100% cpu usage and had to hard reboot), but the cpu usage was low. Upgrading to 11.8 shows that both opencl processes use 100% of one core (haven't had the x server crash yet).

0 Likes

I just had xorg freeze as it did with 11.6, so I'm switching back to 11.6 where I get low cpu usage at least. Perhaps this is an xorg bug, but it certainly never happened with my nvidia hardware.

0 Likes

Bump.

 

Any news on a fix yet AMD?

0 Likes

Come on guys! This is a major bug and it is still not fixed? After two releases?

Could you please give this issue a higher priority since so many of us are suffering from that bug?

Thanks!

0 Likes

Yup... But electric companies are happy ! (Maybe the driver team does have a percentage from the electric bills ? ;-))

We are giving them money 'for free' when doing OpenCL computations !

//Sarcasm off.

0 Likes

I have recenlty purchased Radeon 6950 1GB in addition to my 5770 1GB.

With 11.6 i was unable to use both cards - only 6950 (installed in primary slot on MB) 

With 11.7 and 11.8 I am able to use them both , but cpu consuption is high. 

I can provide any additional information if requested

0 Likes

Our development cycle for catalyst releases is usually 3 months.
0 Likes

Micah-

Acknowledged and I am aware about the development cycles, but you know - sometimes it's good to try/change/improve the process.

By that I mean e.g. out-of-bound fixes (call them development hotfixes/betas/alphas/internals etc.).

If a serious issue has been found and it seems it is fixed by the driver team - make some people happy and don't let them wait for three (or more) dreadded months...

Similar situation was with the HD69xx series and the hangs/restarts when OpenCL + UVD or OpenCL + GPU-Z or OpenCL + HW Acceleration (Flash/Video/Aero on) was running... Before the issue was identified and then we got the drivers with the fix I was pulling the hairs out of my head for 3 or more months... and I've nearly turned away from AMD/ATI...

0 Likes

Update : 

Rolled back to 11.6  - the CPU consuption is high .

In addidion now i cant update back to 11.8 - getting "Driver install : the INF file was not found" error ...

0 Likes

For f***s sake! Everyone using recent Catalyst versions is suffering from this problem!

Why is it so hard for AMD to bring a hotfix driver?

 

The issue is easy to reproduce:

a) take *any* AMD graphics card

b) take *any* OpenCL program

 

Question: Are you guys not testing your software before you deliver it? Or do you just don't care? I mean, helloho, always 100% CPU utilization is not that easy to miss ...

0 Likes

As I agree with your of view Tristan23, I don't like this kind of language.

I believe that if we threat each other with respect we can expect the same from the other side.

 

A happy new info - I've recently upgraded to the new RC version of 11.9 driver and I can happily confirm the issue with 100% usage is now SOLVED !

DriverVer=08/10/2011, 8.890.0.0000
8.89-110810a2-124125C

Thank you driver devs for kicking in the fix one driver release ahead (aaanyway - I still think this kind of 'fixes' should be in a hotfix driver 😉 )

0 Likes

Originally posted by: PrEzi

 

A happy new info - I've recently upgraded to the new RC version of 11.9 driver and I can happily confirm the issue with 100% usage is now SOLVED !

 

 



 

Well, I can't! Still having high CPU usage (100%) with 11.9.

0 Likes

some of my users tested it. it looks like that if its only a single GPU, the bug is fixed. if its more than one GPU it is still unfixed and stays at 100% CPU consumption.

0 Likes

Originally posted by: quadboon some of my users tested it. it looks like that if its only a single GPU, the bug is fixed. if its more than one GPU it is still unfixed and stays at 100% CPU consumption.


That explains why I still have the problem!

I do have a host with two 6970s.

God!! This is so typic AMD!! Fixing only 50% of the bug ...

I seriously hope this bug will be gone in the final 11.9 release.

0 Likes

I tried Catalyst 11.9 on Linux and the bug is *Still* there.

It's really shocking how AMD can go through release after release and let a huge bug like this go unfixed.

Right now I manage over 50 AMD GPUs, mostly 58xx series, but some 69xx series as well.  I can use Catalyst 11.6, which doesn't have the bug (at least on Linux).

 I had planned to replace 50 of them with 78xx series cards and buy another 20 when they are released, but I won't buy any 78xx/79xx because they will require a new version of the drivers which will include the CPU bug.  No chance to use an old version of the drivers to avoid the bug.

Seems like a real mistake to leave open that issue and provide a roadblock to people buying more of your product. 

AMD, please fix this issue if you want any more of my business.

0 Likes

Originally posted by: amazingrando I tried Catalyst 11.9 on Linux and the bug is *Still* there.

It's really shocking how AMD can go through release after release and let a huge bug like this go unfixed.

Right now I manage over 50 AMD GPUs, mostly 58xx series, but some 69xx series as well.  I can use Catalyst 11.6, which doesn't have the bug (at least on Linux).

 I had planned to replace 50 of them with 78xx series cards and buy another 20 when they are released, but I won't buy any 78xx/79xx because they will require a new version of the drivers which will include the CPU bug.  No chance to use an old version of the drivers to avoid the bug.

Seems like a real mistake to leave open that issue and provide a roadblock to people buying more of your product. 

AMD, please fix this issue if you want any more of my business.

Amazingrando,

Linux issue will be fixed in upcoming release. I can't tell the time lines of fix.  I will get back you with more information if i am allowed to pass.

0 Likes

I'm sorry that it took awhile to fix this issue, but the fix to remove 100% CPU usage on linux was submitted late last week. I can't give exact dates on fixes, but it should be fixed in the upcoming catalyst release.
0 Likes

What about 100% CPU bug on Windows?
It still exists in 11.9 with 2+ GPU present.

This is starting to get rediculous.  It makes AMD driver team look utterly inept when YOUR OWN EXAMPLES exhibit the bug.

Is there any fix planned for 100% CPU bug in Windows w/ 2+ GPU present?

0 Likes

Originally posted by: MicahVillmow

I'm sorry that it took awhile to fix this issue, but the fix to remove 100% CPU usage on linux was submitted late last week.


bla bla bla ... the Windows issue was reported ages ago - and it still exists. Even in 11.9.

For more than one GPU you still get 100% CPU load per GPU.

Shame on you!

0 Likes

I have Radeon 6970 and GeForce 560 in the same system. With Catalyst 11.8 and GeForce driver 280.26, both cards used one full CPU core each (so, for example, if I have a CUDA app and an OpenCL app running at the same time, I'd see two CPU cores fully loaded and two CPU cores idle).

With Catalyst 11.9, the OpenCL app no longer uses CPU (usage ~1-2%).

0 Likes

Yeah the 11.9 fixes SINGLE AMD GPU 100% bug.  However if you installed a second 6970 you would be right back at 100% CPU usage.

0 Likes

Originally posted by: hashman Yeah the 11.9 fixes SINGLE AMD GPU 100% bug.  However if you installed a second 6970 you would be right back at 100% CPU usage.

 

I see. But it's still curious to note that NVIDIA has the same problem in their current drivers.

0 Likes

I see. But it's still curious to note that NVIDIA has the same problem in their current drivers.


That's because they are both Made in China, possibly by the same people 😉

0 Likes

Any news for this issue?

0 Likes