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Profile MC707
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Message 36989 - Posted: 6 Mar 2010, 2:33:13 UTC

Ok so I just saw this option in my milkyway@home preferences. I just want to know exactly what it is, and more specifically, why default is 128 compared to the humongous 50000 maximum, and what would be an appropriate amount. Finally, would 50 k burn my GPU or something xD?

Thanks in advance.
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NuclearRage

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Message 37117 - Posted: 10 Mar 2010, 3:39:43 UTC

would also like to know this as well , i am new to the project
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Emanuel

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Message 37146 - Posted: 10 Mar 2010, 19:43:51 UTC

I don't have a technical understanding of the preference, but I believe it essentially indicates how long the application can request control over the GPU at a time. That means that for higher values, the application can do more calculations in a row without giving control back to the operating system, but that also means that anything the operating system wants to do (such as drawing to the screen to update what you see) will have to wait until it gets control. So it's a trade-off between system responsiveness and Milkyway application performance - however, the amount of performance gained by using a higher setting may be negligible.
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nmeofdst8

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Message 37147 - Posted: 10 Mar 2010, 19:55:55 UTC - in response to Message 37146.  

I don't have a technical understanding of the preference, but I believe it essentially indicates how long the application can request control over the GPU at a time. That means that for higher values, the application can do more calculations in a row without giving control back to the operating system, but that also means that anything the operating system wants to do (such as drawing to the screen to update what you see) will have to wait until it gets control. So it's a trade-off between system responsiveness and Milkyway application performance - however, the amount of performance gained by using a higher setting may be negligible.


I'm 99% sure from experience in other areas...its "memory" block usage. Basically how much Video RAM can be dedicated for tasks. Thus the "interface lag" at "higher values"

I have a GTX280, set it to 50000 and can't tell a difference video wise unless I play a full screen video file, then get the occassional chop.
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Anthony Waters

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Message 38264 - Posted: 7 Apr 2010, 2:57:05 UTC

The field concurrent blocks dictates how much of the GPU will be used by the application in a single iteration. The more concurrent blocks the faster the workunits are finished, but it will cause more user interface lag.
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Profile Sutaru Tsureku

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Message 40537 - Posted: 19 Jun 2010, 1:33:10 UTC
Last modified: 19 Jun 2010, 1:44:48 UTC

I tested on my manufacturer OCed GTX260-216 @ 680/1500/1250 MHz [core/shader/RAM] the stock 128 and 50,000 and the calculation times are the same.

Which blocks are meant with this settings?

GTX260-216 - GT200b, 55nm:
Shader? This are 216.
CUDA Cores? This are 27.
ROPs? This are 28.
Shader-Cluster? This are 9.
Texture units? This are 72.
Fillrate Pixel (GP/s) - 16,128.
Fillrate Texture (GT/s) - 41,472.
[wikipedia.org/GeForce_200_Series]

Maybe I would need to insert the correct value of my GPU?


Thanks! :-)


[EDIT: The screen is connected to the onboard GPU. The GTX260-216 do only CUDA.]
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Message 40543 - Posted: 19 Jun 2010, 18:42:26 UTC - in response to Message 38264.  
Last modified: 19 Jun 2010, 18:43:57 UTC

The field concurrent blocks dictates how much of the GPU will be used by the application in a single iteration. The more concurrent blocks the faster the workunits are finished, but it will cause more user interface lag.


Much like Sutaru I didn't see any difference in completion time or interface responsiveness between 128 and 50,000. And my screen is run through the video card.

GTX260 55nm with 216 cores as well. Perhaps it would have more effect with single precision calculations where the gpu is more completely used for the computation?


nmeofdst8, As for memory usage, GPU-Z reports the same ammt of memory used no matter what the setting is set to.
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Message 49861 - Posted: 4 Jul 2011, 5:51:18 UTC
Last modified: 4 Jul 2011, 5:56:44 UTC

With gtx560ti and 384 concurrent (as many as stream processors) and no cpu in milkyway preferences I have gained 2 minutes from 8 min to 6 min, any higher value results in no acceleration or no run at all cuda milkyway chunks.
The only problem I cannot remove cpu tasks n-body simulation, even i have forbidden cpu for ever. it is heat maker, always 100% on one cpu processor.
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newfuntek

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Message 49866 - Posted: 4 Jul 2011, 9:40:25 UTC - in response to Message 49861.  

Maybe I was wrong, it only works with 128, anybody has any clues about this feature? With 128 still have 6 min without any cpu...
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Matt Arsenault
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Message 49935 - Posted: 6 Jul 2011, 6:33:56 UTC - in response to Message 49866.  

Maybe I was wrong, it only works with 128, anybody has any clues about this feature? With 128 still have 6 min without any cpu...
This isn't a feature. I think the old CUDA version might have used it. If you're changing it now it won't do anything.
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Message boards : Number crunching : Amount of concurrent blocks

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