Welcome to MilkyWay@home

Selecting tasks for CPU


Advanced search

Message boards : Number crunching : Selecting tasks for CPU
Message board moderation

To post messages, you must log in.

AuthorMessage
ProfileBill Eckard

Send message
Joined: 10 Jun 11
Posts: 2
Credit: 3,065,946
RAC: 0
3 million credit badge11 year member badge
Message 70117 - Posted: 19 Sep 2020, 14:34:39 UTC

I am processing GPU tasks on multiple GPU's and I also wanted to process CPU tasks. However, I received Separation tasks for the CPU which are better processed with the GPU. I there any way to limit the CPU processing to only tasks that specifically require processing this way, such as N-Body?
ID: 70117 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
ProfileKeith Myers
Avatar

Send message
Joined: 24 Jan 11
Posts: 642
Credit: 497,941,874
RAC: 200,540
300 million credit badge11 year member badgeextraordinary contributions badge
Message 70119 - Posted: 19 Sep 2020, 21:05:05 UTC - in response to Message 70117.  

Create two different venues. One with cpu only and one with gpu only. Then run two BOINC clients with each one crunching either the cpu or gpu venue.
ID: 70119 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
ProfileBill Eckard

Send message
Joined: 10 Jun 11
Posts: 2
Credit: 3,065,946
RAC: 0
3 million credit badge11 year member badge
Message 70120 - Posted: 20 Sep 2020, 17:57:23 UTC - in response to Message 70119.  

Thank you
ID: 70120 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Diplomat

Send message
Joined: 3 May 19
Posts: 2
Credit: 12,505,669
RAC: 23,012
10 million credit badge3 year member badge
Message 70125 - Posted: 24 Sep 2020, 3:26:34 UTC
Last modified: 24 Sep 2020, 3:29:18 UTC

How did you decide that NBody are better for CPU than Separation?

Pointswise Separation tasks grants you more credits: 227 credits for about 1,5 hrs of 1 CPU
While Nbody 8 CPUs for 15 min only 36 credits,

That's actually quite frustrating 8*15=120 min CPU time for only 36 credits =( very very conservative
ID: 70125 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Profilemikey
Avatar

Send message
Joined: 8 May 09
Posts: 2984
Credit: 497,717,591
RAC: 193,424
300 million credit badge13 year member badgeextraordinary contributions badge
Message 70126 - Posted: 24 Sep 2020, 11:48:02 UTC - in response to Message 70125.  

How did you decide that NBody are better for CPU than Separation?

Pointswise Separation tasks grants you more credits: 227 credits for about 1,5 hrs of 1 CPU
While Nbody 8 CPUs for 15 min only 36 credits,

That's actually quite frustrating 8*15=120 min CPU time for only 36 credits =( very very conservative


But if you run 6 tasks in the same 1 1/2 hours you will get 216 credits
ID: 70126 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Diplomat

Send message
Joined: 3 May 19
Posts: 2
Credit: 12,505,669
RAC: 23,012
10 million credit badge3 year member badge
Message 70128 - Posted: 24 Sep 2020, 12:11:21 UTC - in response to Message 70126.  
Last modified: 24 Sep 2020, 12:21:58 UTC

But if you run 6 tasks in the same 1 1/2 hours you will get 216 credits

Don't forget core count!

NBody: 6 tasks х 1 set of 8 CPUs yield 216 in ~1,5 hrs
Separation: 1 task * 8 CPUs yield 1816 in a same ~1,5 hrs
ID: 70128 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Profileeiernacken1983

Send message
Joined: 1 Jul 19
Posts: 5
Credit: 4,503,883,588
RAC: 4,644,202
3 billion credit badge3 year member badge
Message 70129 - Posted: 24 Sep 2020, 13:09:10 UTC - in response to Message 70125.  

How did you decide that NBody are better for CPU than Separation?

Pointswise Separation tasks grants you more credits: 227 credits for about 1,5 hrs of 1 CPU
While Nbody 8 CPUs for 15 min only 36 credits,

That's actually quite frustrating 8*15=120 min CPU time for only 36 credits =( very very conservative


I think he compared the time of the separation tasks when processed on GPU vs CPU.

Separation on GPU: 12 - 300 seconds (depending on the gpu)
Separation on CPU: 5400 seconds

less than 300 seconds < 5400 seconds --> so it is not efficient to process separation on CPU

As NBody can only be processed on the CPU he doesn't want to block his CPU with Separation units.

If you use a GPU the you don't care about the small amount of credits you can make with a CPU.
(Separation: 1 task * 8 CPUs yield 1816 in a same ~1,5 hrs --> separation on Radeon VII: 12 Secs/task --> 300 Tasks per hour --> 450 tasks per 1.5 hours = 68,100 credits)

So if you want to maximize scientific output (not credits) for the project you should do separation on GPU and NBody on CPU. I think this was the intention of Bill Eckard. If yes, I agree with him :-)
ID: 70129 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote

Message boards : Number crunching : Selecting tasks for CPU

©2022 Astroinformatics Group