Bitcoin Forum

Hi,

I have two 6970 in my system.

- When I use a Catalyst version > 11.5 my CPU shows 100% load per core when running OpenCL code (before it was around 3%).

- When I use Catalyst < 11.5 I see only one of my two GPUs in the system.

Question: How can I use BOTH my GPUs AND don't have this 100% load bug?

cheers,
F.

Simple ... you can't until AMD gets around to fixing it.   >:(

11.10 fixes 1 (single) GPU 100% CPU bug in both Linux & Windows.
11.11 fixes 2+ GPU 100% CPU bug in Linux but not Windows.

Currently there is no fix for 2+ GPU 100% Bug in Windows.

yell @ ATI/AMD

you havent mentioned what OS or miner you are using - useful info for accurate answers :)

a workaround for ppl with multi cores on windows is set miner affinity to one core, this way its only 100% on 1 core and you can use others :)
task manager > processes tab > right click miner process> set affinity > uncheck all but 1 core :)

11.6 (original, not 11.6b release) seems to work the best for most. If you have a multi-core CPU, you can force all your miners to run only on the same single CPU core by forcing CPU affinity. Here's a batch file that starts my miners as an example (if you are on Windows):


The affinity setting is actually a bitmask in hex, 01=CPU0, 02=CPU1, 03=CPU0+CPU1 etc.
I am also running Phoenix from source, not the binary, so correct the exe above if you are the other 99%.

this bug has been known for a long time thats what the search button is for =p

If you are not comfortable with batch files, an alternative would be to use GUIMiner, which has checkboxes for the specific CPU cores you want to assign to each GPU. As was mentioned before, you set them all to the same core. That one core will be used 100%, but if you have a dual or quad core machine, the remaining cores will be free.

11.12 fixes the 100% bug on my machine (APU A6-3650 + HD 6670)
Me happy :)

Is there any mining speed increase with the newest version?

Some people are reporting ~20 Mh/s decreases.

I'll stick with the high CPU usage then... it's not causing that much of a temperature increase for me and I don't use the machines for anything other than mining except the occasional test web server config, but even that's rare... (They're built from spare parts I had laying around and a couple of cheap 5830s from ebay)

I haven't fount a drop in perf.
Currently 120 on the 6670 (@900) and 40 on the A6 (at stock 444)

No speed decrease at all for me. Version 11.12 seems to have finally fixed this annoying bug under Linux, and the hashrate of my two 5870's is the same as before, totaling ~850 MH/s.

If you have installed 11.12 (or 12.1 driver), start its setup (i.e. c:\ATI\Support\11-12_vista64_win7_64_dd_ccc_ocl\setup.exe )
Then uninstall Ati Stream (AMD APP SDK) only and install:
for 64-bit Vista/Windows 7:  http://www2.ati.com/drivers/11-2_vista_win7_64_ocl.exe
for 32-bit Vista/Windows 7:  http://www2.ati.com/drivers/11-2_vista_win7_32_ocl.exe
for 64-bit XP: http://www2.ati.com/drivers/11-2_xp64_ocl.exe
for 32-bit XP: http://www2.ati.com/drivers/11-2_xp32_ocl.exe

You will have previous mining performance and no 100% CPU Bug!

I tried this and can't really recommend it. Performance was back to normal, but total core usage fluctuates between 20-50% each on all cores (4 core). If you quarantine the processes to 1 core, one of the cards can't get more than 96% and loses mhash, and that core's usage goes back to 100%. (Previously all 3 were steady at 99%.)

This rig was a 3x 5830 Win7 64x AMD x4 core.

Thanks for the suggestion though. It might work better for other setups.

To start your miners with Above Normal priority, use script with following commands to assign each miner to the different core:

start /AFFINITY x /ABOVENORMAL miner_command
where x = 2^{core no.} (i.e. 1,2,4,8 ...)

This way you can get rid of the fluctuations and even mine Solidcoins or Litecoins on all CPU cores and Bitcoins on GPUs.

@up
Are you sure that the miners are responsible and not some other processes?
I use Windows 7 x64 and phoenix miners and they have 1% CPU usage in the Task Manager.
I have Intel C2Q 9450 + Asus Commando (p965) MoBo, Radeons 5850 and 5830.

Thanks, but I am sure. This is a dedicated rig and usage is near 0% when it's not mining. It's been a while since I tried phoenix though, I'll give it another shot, but in the past phoenix made things worse as far as resources go.

that will wear out one of your cores pretty quick, unless your script rotates the cores.

I don't overclock CPU and its cooling is sufficient (Scythe Mugen), so wearing the CPU out is not feasible.
Besides, my point is to NOT load the cores in 100%, to save energy or increase profits by mining solidcoins !

My phoenix batch script goes like this:

wait, why are you setting to different affinity? wouldn't it be better to pack all instances into one core? it doesn't affect speeds for me

I have assigned BTC miners to different CPU cores at increased priority to allow mining solidcoins on four CPU cores at the same time.

Why are you mining ScamCoins? 

For purpose of this thread: to test if I can mine BTC and SC at the same time. And to get rich  ;D