BRP5-cuda32-nv270 runs faster on old card

felixonmars
felixonmars
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Topic 197225

Hi all, I have two machines with different display card, one is GTX 650 Ti, the other is 9600 GT.

The problem is, the WUs run 8x faster on the older one (9600 GT)

I did try to run it on 550 Ti, and it's still a lot faster than 650 Ti.

All tasks were running under same OS (Arch Linux x86_64, with latest 3.11.x linux kernel, and latest nvidia driver 325.15)

I'm not familiar with GPU, so I could not really tell why it's like this - but could anyone help me?

Two WUs for comparison:
http://einsteinathome.org/task/405344492
http://einsteinathome.org/task/404679225

And one more strange thing is, I claim fairly low credits from the WUs, like for the two above WUs:
Claimed credit / Granted credit
48.38 / 3,333.00
20.51 / 3,333.00

They were both shown as "Completed and validated" though.

Thanks for any help!

Twitter: @felixonmars

felixonmars
felixonmars
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BRP5-cuda32-nv270 runs faster on old card

Oops I think I found some clue:

Using CUDA device #0 "GeForce 9600 GT" (64 CUDA cores / 312.00 GFLOPS)

vs

Using CUDA device #0 "GeForce GTX 650 Ti" (0 CUDA cores / 0.00 GFLOPS)

Why's the latter shown as 0?

Twitter: @felixonmars

Neil Newell
Neil Newell
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It seems very likely the 8x

It seems very likely the 8x WU's were using the GPU (9600GT) but the slower ones are just using the CPU instead. For some reason the GTX650Ti isn't being used.

Can you post the BOINC start-up messages?

On the strange thing about claiming low credits for WU's, I think this is what happens your GPU does work a lot faster than a CPU can. If the CPU did the work, the claimed credit would be higher - but because GPU's are so much faster, the claimed credit is lower. The 'granted' credit for a particular task is always the same, no matter how you did the work - so really 'claimed credit' isn't something to worry about.

mountkidd
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RE: Oops I think I found

Quote:

Oops I think I found some clue:

Using CUDA device #0 "GeForce 9600 GT" (64 CUDA cores / 312.00 GFLOPS)

vs

Using CUDA device #0 "GeForce GTX 650 Ti" (0 CUDA cores / 0.00 GFLOPS)

Why's the latter shown as 0?


The application code reporting these values works for GTX 5xx and earlier. GTX 6XX/7XX are reported incorrectly as zeroes, but do in fact produce results in spite of what the message says.

Gord

felixonmars
felixonmars
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RE: RE: Oops I think I

Quote:
Quote:

Oops I think I found some clue:

Using CUDA device #0 "GeForce 9600 GT" (64 CUDA cores / 312.00 GFLOPS)

vs

Using CUDA device #0 "GeForce GTX 650 Ti" (0 CUDA cores / 0.00 GFLOPS)

Why's the latter shown as 0?


The application code reporting these values works for GTX 5xx and earlier. GTX 6XX/7XX are reported incorrectly as zeroes, but do in fact produce results in spite of what the message says.

Gord

Thanks for the info, and is this also the cause that GTX 6XX cards run so slowly?

Twitter: @felixonmars

Neil Newell
Neil Newell
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RE: The application code

Quote:
The application code reporting these values works for GTX 5xx and earlier. GTX 6XX/7XX are reported incorrectly as zeroes, but do in fact produce results in spite of what the message says.
Gord


Aha, thanks; I didn't know that.

Quote:

Thanks for the info, and is this also the cause that GTX 6XX cards run so slowly?

I'm not familiar with the GTX650, but 185,000 seconds for the GTX650 task seems far too long (especially given your 9600GT did a similar task in about ~27,000 seconds).

Here's an extract from the 9600GT log:

[21:53:24][12146][INFO ] CUDA global memory status (initial GPU state, including context):
------> Used in total: 293 MB (219 MB free / 512 MB total) -> Used by this application (assuming a single GPU task): 0 MB
[21:53:24][12146][INFO ] Using CUDA device #0 "GeForce 9600 GT" (64 CUDA cores / 312.00 GFLOPS)
[21:53:24][12146][INFO ] Version of installed CUDA driver: 5050
[21:53:24][12146][INFO ] Version of CUDA driver API used: 3020

...and here's the GX650Ti.

------> Used in total: 145 MB (879 MB free / 1024 MB total) -> Used by this application (assuming a single GPU task): 0 MB
[20:17:13][7147][INFO ] Using CUDA device #0 "GeForce GTX 650 Ti" (0 CUDA cores / 0.00 GFLOPS)
[20:17:13][7147][INFO ] Version of installed CUDA driver: 5050
[20:17:13][7147][INFO ] Version of CUDA driver API used: 3020

That all looks reasonable, though I see that 'Signal 15' was thrown once in the log for the GTX650Ti.

Any ideas, Gord? They are both BRP5 tasks, both credited 3,333.

mountkidd
mountkidd
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RE: Thanks for the info,

Quote:
Thanks for the info, and is this also the cause that GTX 6XX cards run so slowly?


I don't think so. That message is [INFO] only and I don't believe the values are used anywhere.

What I do see in your scheduler log is that you have not freed up a cpu core to feed the gpu. A second issue might be the driver. This thread talks about a similar problem to yours and has a link to some info about recent Linux drivers.

Gord

felixonmars
felixonmars
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RE: What I do see in your

Quote:

What I do see in your scheduler log is that you have not freed up a cpu core to feed the gpu. A second issue might be the driver. This thread talks about a similar problem to yours and has a link to some info about recent Linux drivers.

Gord

Thanks a lot. I've tried freed up a cpu core but that doesn't make a difference - now I'm going to downgrade my driver to 304.xx and test.

Twitter: @felixonmars

felixonmars
felixonmars
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Oops, after downgraded driver

Oops, after downgraded driver to 304.108 (from 325.15), it's much faster and should be normal now.

Thanks a lot for all your help!

Twitter: @felixonmars

Bikeman (Heinz-Bernd Eggenstein)
Bikeman (Heinz-...
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Hi! You might have ssen

Hi!

You might have ssen the thread (in the Crunchers' Corner" section) that discusses results from the latest 331.xx series Beta drivers. It seems the problem is fixed in the latest beta drivers from NVIDIA, so there is hope for the next official driver.

Cheers
HB

felixonmars
felixonmars
Joined: 16 Nov 12
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Credit: 3409581
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Thanks for the info! I'll try

Thanks for the info! I'll try the 331 series once a stable version is tagged.

Twitter: @felixonmars

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