Bitcoin Forum

Hi guys,

I just noticed that the 100% CPU bug finally went away after installing AMD catalyst 11.12
and having only one monitor plugged into my main card (crossfire disabled).

I am using Windows 7 32 bit. We have been waiting for this for months!

Awesome!

I can confirm. CPU bug is finally gone with catalyst 11.12 Windows x64.

Also confirmed.   However,  I can no longer run a 256 worksize on my 5970's.  :(  Lost about 26mhash/sec per GPU.   Pleh.   Just can't win with these drivers...

  that bites. have you tried it with the other vector settings and the smaller worksize?

Yeah.   I haven't tried every combination because I ran out of time,  but I couldn't seem to max out the GPUs anymore (bouncing between 92 and 93 percent activity).

  rgr, thanks for the reply. I will be watching for your feedback on the results if you have time to check the other combos. I'm not able to get to my system to up the Cata drivers atm or would flip thru them myself.

really ? 

Strange, it doesn't seem to work on just any rig for me. One system with two cards mining (no onboard gpu) is fine. Here I get 0-4% pending cpu usage. Doesn't even matter if I put in a dummy plug or not. I still use those sometimes b/c they make overclocking much easier.  On my other rig, I haven't yet been able to get it to work yet. Either my drivers are messed up although I spend quite some time installing and deinstalling/sweeping or is it cause I'm using multiple (3+) cards including onboard graphics or is it some software glitch...

On 5870s and 5770s there seem to be no issues with worksize for me.

Hasnt fixed cpu bug for me on win7/32 AND speed went down by 30mhash.
Reinstalled 11.11  speed is still down...  will update after checking

Edit: 3x5850 in system

Ok, just to get this out of the way again. Are any of you running multiple cards who had the 100% cpu bug fixed?

What about Linux ?

What is the CPU usage like on a low end CPU with multiple GPUs with a clean install of 11.12 ?

perhaps I should add: my fixed computer runs an AMD X6 cpu. Until this day, I had always had one fully used core. No luck still on AMD Dual Cores.

Once again: Win 7 32 bit, two actively mining GPUs.

Now works like charm on my dual core system (no onboard gpu present).

It works! Finally!  ;D
Very low cpu % on all cores.

Windows 7 x64
Core i5 2500k
2x Radeon HD6990

Wow, thank god! It's about time!

I too can also confirm that mining on win 7 64 bit with a radeon 5970 with crossfire enabled works without 100% per core cpu usage.

For the longest time I'd get the best hash rates with a 256 worksize on my 5970.  Then for some reason (maybe I switched drivers, I don't remember) 128 gave me the best results.  What miner version are you using?  I'm using Phoenix 1.50.

OK, so I tried installing 11.12 and 12.1 both, with the same results.

I tried this on one of my rigs: AMD x4 core, with 3x 5830s - Win 7 64bit

The 100% CPU bug is ..... improved I guess.

CPU usage before the bug on this rig was under 4% (of one core) total for 3 instances of poclbm. Now it's 40% - I wouldn't call that solved.

CGminer uses 40-50% if restricted to 1 core, but then GPU utilization drops below 99% - without restriction it uses about 10-15% per core.

But now for the real bad news - card performance dropped 14%. I had about 930Mh on this machine. Each card is running 950/300 clocks. Now I'm getting around 800Mh. I've tried several miners and messed with the settings....this is the best I can get.

I'll be switching back to 11.11 soon.

I installed 11.12 and went from about 412-414 MH/s per core down to 368 MH/s per core.  I lost over 40 MH/s per core, or around 80 MH/s total on my 5970 :(  But CPU usage is only 60%.  Cool I guess.

The Catalyst package installs two independent components that may individually affect performance: the video card driver, and the OpenCL SDK and DLLs. You can start the Windows installation, cancel after it has extracted the components, and then explore to the directory containing the individual components for manual installation. Note, the "display driver only" download actually includes OpenCL, drag and drop transcoding, and Visual C++ runtimes too.

I would be curious if just the new driver with older OpenCL or old driver with new OpenCL yields an improvement in the issues above (I don't have multi-gpu to thoroughly test).

Here are the typical extracted locations:

Video driver (specify this location when using device manager-> update video card driver):

C:\ATI\Support\11-12_vista32_win7_32_dd\Packages\Drivers\Display\W7_INF

OpenCL installer:

C:\ATI\Support\11-12_vista32_win7_32_dd\Packages\Apps\OpenCL\OpenCL.msi

I can answer my own question now. The video card driver gives a minimal improvement over 11.6: at lower aggression settings, phoenix gets about 1 mhash more, but about the same at max settings.

The OpenCL version 2.6 included in the 11.12 package will completely hose your system for a 10%+ loss, you'll then need to uninstall the OpenCL installation or use the "uninstall all ATI software" option, and also find and delete C:\Windows\System32\amdocl64.dll, C:\Windows\System32\amdoclcl64.dll, C:\Windows\System32\OpenCL.dll, and reinstall the old OpenCL to get your performance back.

I can't test multi-GPU CPU usage though, so try to install the new driver only (through device manager, for each video card, after extracting the driver components, on Windows) and rebooting.

Didn't notice any performance loss while the cpu bug went away completely. All lower end cards though.

All I had to do was copy the 6 dlls mentioned in the other thread from 2.5 on top of the 2.6 ones. That fixed the performance drop and CPU usage went back to 100%. A lot less hassle.

I can confirm ATI drivers version 11.12 solve the problem under Linux, too. The CPU usage of phoenix went down to 1%.
Now I can mine both Bitcoin and Litecoin in the same rig... Yippee!

Link to other thread plz?

CPU usage for me went from 100% to around 60% or 70%. It bounces around. On my single card machine my reported hashrate went down 20mhs but my pool is saying it is the same as before based on submitted shares.

i've posted this in a couple other threads- i run a 5870 and 5770 with a slight loss in hashing power usin GUIminer but the CPU bug is gone for me

Another satisfied customer. Bug is gone with marginal performance loss.

Scroll to post 11.
https://bitcointalk.org/index.php?topic=54693.0

CPU problem solved for me.  I'm running debian.

I can hardly believe it, it actually works! 2x 6950, GUIMiner, W7 64bit. 1-2% CPU usage, no noticable loss in performance.

Could any of you please tell me if you got it to work on a mainboard with an integrated gpu? I got rid of the cpu bug only on my non-onboard gpu rigs. I do use the internal graphics to run windows, in order to not lower the hash rate while working. Cheers!

Still seem to have the problem on one Win7x64 machine, but not on another.  WTH

downgrade to 2.1. no cpu bug, no performance loss either :D

I believe there were performance improvements with the newer sdks, so downgrading to 2.1 would mean quite a loss in performance, or wouldn't it?

No, I've not heard of any performance improvements. 

But downgrading isn't a option, as the one having the problem is is my primary gaming rig.

Upgraded to 11.12 on one of my rigs... 2x6950 went from 740mhash to 680mhash...  but the CPU bug is gone.  Not sure if the tradeoff is worth it on this box.

Well, even though I upgraded my gaming rig, it seems the driver update didn't take.  I re-did it and the CPU bug does indeed seem to be gone on 11.12.  Hoo-ray!