Task taking 1 CPU plus 1 GPU ?

Matthew S. McCleary
Matthew S. McCleary
Joined: 5 May 09
Posts: 6
Credit: 183,078
RAC: 0
Topic 194746

I've got a quad-core Phenom box with a 9600 GT and a 9600 GSO.

Yesterday I was scratching my head trying to figure out why it was only running four tasks (that is, two CPU and two GPU) when it should have been running four CPU and two GPU.

I figured out what was happening -- it was running two Einstein@home tasks and those two tasks were both using 1 CPU core and 1 nVidia GPU at the same time! BOINC even said "1.00 CPUs plus 1.00 NVIDIA GPUs" for each task.

Any idea why that was happening? I suspended each task, but then BOINC started running two more Einstein tasks doing the same thing. I had to reset the Einstein@home project to get it to behave.

I thought Einstein couldn't even use CUDA...

Michael Karlinsky
Michael Karlinsky
Joined: 22 Jan 05
Posts: 888
Credit: 23,502,182
RAC: 0

Task taking 1 CPU plus 1 GPU ?

Quote:

I've got a quad-core Phenom box with a 9600 GT and a 9600 GSO.

Yesterday I was scratching my head trying to figure out why it was only running four tasks (that is, two CPU and two GPU) when it should have been running four CPU and two GPU.

I figured out what was happening -- it was running two Einstein@home tasks and those two tasks were both using 1 CPU core and 1 nVidia GPU at the same time! BOINC even said "1.00 CPUs plus 1.00 NVIDIA GPUs" for each task.

Any idea why that was happening? I suspended each task, but then BOINC started running two more Einstein tasks doing the same thing. I had to reset the Einstein@home project to get it to behave.

I thought Einstein couldn't even use CUDA...

For info on Einstein CUDA applications, see this sticky thread.

BTW, the so called ABP2 application is supposed to use one CPU && one GPU.

Michael

Michael Goetz
Joined: 11 Feb 05
Posts: 21
Credit: 3,060,627
RAC: 1

RE: I've got a quad-core

Quote:

I've got a quad-core Phenom box with a 9600 GT and a 9600 GSO.

Yesterday I was scratching my head trying to figure out why it was only running four tasks (that is, two CPU and two GPU) when it should have been running four CPU and two GPU.

I figured out what was happening -- it was running two Einstein@home tasks and those two tasks were both using 1 CPU core and 1 nVidia GPU at the same time! BOINC even said "1.00 CPUs plus 1.00 NVIDIA GPUs" for each task.

Any idea why that was happening? I suspended each task, but then BOINC started running two more Einstein tasks doing the same thing. I had to reset the Einstein@home project to get it to behave.

I thought Einstein couldn't even use CUDA...

You diagnosed the situation correctly.

The current E@H GPU app still runs mostly on the CPU, and only uses the GPU a little bit. So, it ties up a whole CPU core AND your whole GPU. Although the GPU app runs faster than the CPU-only app, it doesn't run a whole lot faster.

If you have other projects you can run on your GPU, you're probably better off not running E@H GPU apps yet -- IMHO they're very immature at this point and a waste of GPU resources. If you're not running anything else on your GPU, then it doesn't hurt. It will (in most cases) run faster than the CPU-only application. (Although, if you have a fast CPU and slow GPU, some people have reported that the GPU app runs *slower* than the CPU app. YMMV)

Want to find one of the largest known primes? Try PrimeGrid. Or help cure disease at WCG.

Matthew S. McCleary
Matthew S. McCleary
Joined: 5 May 09
Posts: 6
Credit: 183,078
RAC: 0

RE: You diagnosed the

Message 96717 in response to message 96716

Quote:


You diagnosed the situation correctly.

The current E@H GPU app still runs mostly on the CPU, and only uses the GPU a little bit. So, it ties up a whole CPU core AND your whole GPU. Although the GPU app runs faster than the CPU-only app, it doesn't run a whole lot faster.

If you have other projects you can run on your GPU, you're probably better off not running E@H GPU apps yet -- IMHO they're very immature at this point and a waste of GPU resources. If you're not running anything else on your GPU, then it doesn't hurt. It will (in most cases) run faster than the CPU-only application. (Although, if you have a fast CPU and slow GPU, some people have reported that the GPU app runs *slower* than the CPU app. YMMV)

Is there a way I can configure Einstein to use only the CPU, yet allow other projects to use the GPU if they wish?

Matthew S. McCleary
Matthew S. McCleary
Joined: 5 May 09
Posts: 6
Credit: 183,078
RAC: 0

RE: For info on Einstein

Message 96718 in response to message 96715

Quote:


For info on Einstein CUDA applications, see this sticky thread.

BTW, the so called ABP2 application is supposed to use one CPU && one GPU.

Michael

Ah, after reading that thread it makes sense. Unfortunately it seemed to be running extremely slowly on my 9600, and I'd prefer to use the GPU for another project. I think when my GTX 260 arrives I'll give ABP2 another shot.

Bikeman (Heinz-Bernd Eggenstein)
Bikeman (Heinz-...
Moderator
Joined: 28 Aug 06
Posts: 3,522
Credit: 692,141,872
RAC: 14,754

RE: Is there a way I can

Message 96719 in response to message 96717

Quote:

Is there a way I can configure Einstein to use only the CPU, yet allow other projects to use the GPU if they wish?

Sure, go to the E@H project preferences http://einstein.phys.uwm.edu/prefs.php?subset=project and deselect the option to use GPU.

The setting will be synced to your PCS when doing the next server communication (can be forced by pushing "update" in BOINC manager).

This will disable GPU for Einstein@Home on all your hosts. If you rather want to disable GPU only for selected hosts, you con assign those hosts to a special venue you do not use (say, "school") and disble GPU processing only for this venue. The venue can be selected on the page showing your host details.

Cheers
HB

Matthew S. McCleary
Matthew S. McCleary
Joined: 5 May 09
Posts: 6
Credit: 183,078
RAC: 0

RE: Sure, go to the E@H

Message 96720 in response to message 96719

Quote:

Sure, go to the E@H project preferences http://einstein.phys.uwm.edu/prefs.php?subset=project and deselect the option to use GPU.

Great! Thanks for the tip.

Bikeman (Heinz-Bernd Eggenstein)
Bikeman (Heinz-...
Moderator
Joined: 28 Aug 06
Posts: 3,522
Credit: 692,141,872
RAC: 14,754

RE: RE: Sure, go to the

Message 96721 in response to message 96720

Quote:
Quote:

Sure, go to the E@H project preferences http://einstein.phys.uwm.edu/prefs.php?subset=project and deselect the option to use GPU.

Great! Thanks for the tip.

You're welcome! But be warned, you might find out that the ABP2 tasks run quite a bit slower on your AMD quad-core CPU. The difference between GPU and CPU task runtime actually in general seems to be much larger for AMD CPUs: the Intel Core2s seem to do a far better job computing the FFTs in ABP2, which is the part that is done on the GPU in the CUDA app. I would not be surprised if the GPU app were faster on your PC by a factor of 1.7 to 1.9. That seems to be about the ratio for my AMD 4850e PCs

CPU : 5700 sec 5.7k sec

GPU (9800 GT "Eco") : 3k sec

Factor: 1.9 (almost twice as fast, and this isn't even a very fast CUDA card). A factor of 2 is probably the upper limit of the speed-up that you can expect.

It will be intersting to see the comparison for your AMD quadcore.

CU
HB

Matthew S. McCleary
Matthew S. McCleary
Joined: 5 May 09
Posts: 6
Credit: 183,078
RAC: 0

RE: You're welcome! But be

Message 96722 in response to message 96721

Quote:


You're welcome! But be warned, you might find out that the ABP2 tasks run quite a bit slower on your AMD quad-core CPU. The difference between GPU and CPU task runtime actually in general seems to be much larger for AMD CPUs: the Intel Core2s seem to do a far better job computing FFTs, which is the part that is done on the GPU in the CUDA app. I would not be surprised if the GPU app were faster on your PC by a factor of 1.7 to 1.9. That seems to be about the ratio for my AMD 4850e PCs

CPU : 5700 sec 5.7k sec

GPU (9800 GT "Eco") : 3k sec

Factor: 1.9 (almost twice as fast).

CU
HB

I stuck with AMD for years since the price/performance ratio was so much better than Intel, but lately I'm finding going with AMD really puts you behind the game as compared to those crunching with Intel chips, especially Core i7s. The SETI guys swear by Intel -- the only computers in the top 20 or so with AMD chips also have four or five GTX 295s. :)

I'll give this some thought. I need to come up with an overall strategy for which DC projects are going to run best on my half-dozen boxes, and maybe detach some.

Bikeman (Heinz-Bernd Eggenstein)
Bikeman (Heinz-...
Moderator
Joined: 28 Aug 06
Posts: 3,522
Credit: 692,141,872
RAC: 14,754

RE: The SETI guys swear by

Message 96723 in response to message 96722

Quote:
The SETI guys swear by Intel -- the only computers in the top 20 or so with AMD chips also have four or five GTX 295s. :)

You'll find the same Intel dominance here at E@H, it's a bit sad :-( .

CU
HB

Michael Goetz
Joined: 11 Feb 05
Posts: 21
Credit: 3,060,627
RAC: 1

RE: You'll find the same

Message 96724 in response to message 96723

Quote:
You'll find the same Intel dominance here at E@H, it's a bit sad :-( .

Yup. For years it was cool and smart to be in the AMD camp -- their chips were faster, cheaper, and drew less power (which is super important for laptops.)

It took a while, but the empire finally struck back with the Core2 chips, which were markedly faster and significantly lower in power consumption than their AMD equivalents. Intel was still more expensive, but at least you were getting more bang for your buck.

The Core i7 is continuing where the Core2 left off. AMD has its work cut out for it; they are definitely behind the curve with respect to CPUs.

Want to find one of the largest known primes? Try PrimeGrid. Or help cure disease at WCG.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.