mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Hardware > GPU Computing > GpuOwl

Reply
 
Thread Tools
Old 2021-02-12, 21:55   #23
ewmayer
2ω=0
 
ewmayer's Avatar
 
Sep 2002
Rep├║blica de California

1162610 Posts
Default

I run 2 instances per card on each of my Radeon VIIs for 2 reasons:

1. Gives an total throughput boost in the 7-10% range;

2. If one job hangs or crashes - infrequent, but it does happen - one minimizes the total throughput hit.

Even if one has a GPU model where 2-instances is slightly slower in total-throughput terms - say no more that 5% - [2] makes it worth doing, IMO.

On the R7 I found negative benefit from > 2 instances.
ewmayer is offline   Reply With Quote
Old 2021-02-13, 07:35   #24
ZFR
 
ZFR's Avatar
 
Feb 2008
Bray, Ireland

11·13 Posts
Default

Quote:
Originally Posted by ewmayer View Post
...
OK, gotcha. Guess I'll test it out and if the throughput is same or slightly lower, I'll go with 2.

Last fiddled with by ZFR on 2021-02-13 at 07:36 Reason: Spelling mistake
ZFR is offline   Reply With Quote
Old 2021-02-19, 15:02   #25
ZFR
 
ZFR's Avatar
 
Feb 2008
Bray, Ireland

100011112 Posts
Default

Quote:
Originally Posted by ewmayer View Post
Even if one has a GPU model where 2-instances is slightly slower in total-throughput terms - say no more that 5% - [2] makes it worth doing, IMO.
On GeForce GTX 970 getting worse results. 12.3 ms/iter when running one instance. When running 2 I get 28.6 average. That's about 16% worse throughput.

Last fiddled with by ZFR on 2021-02-19 at 15:10
ZFR is offline   Reply With Quote
Old 2021-02-20, 09:16   #26
ZFR
 
ZFR's Avatar
 
Feb 2008
Bray, Ireland

8F16 Posts
Default

Actually, never mind. That was when I tested by putting the assigned exponent into worktodo, which does a P-1 on it simultaneously?

When I simply test with the -prp <exp> arguments, the throughput on running two instances is only 2% worse. I'll just use 2 instances for the in-case-it-hangs-or-crashes reason.
ZFR is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
gpuOwL: an OpenCL program for Mersenne primality testing preda GpuOwl 2696 2021-04-18 17:48
Gpuowl / Linux question Prime95 GpuOwl 13 2020-01-03 22:44
Help with OpenCL under Linux and nouveau xilman Software 2 2019-11-14 09:19
GPUOWL AMD Windows OpenCL issues xx005fs GpuOwl 0 2019-07-26 21:37
Can't get OpenCL to work on HD7950 Ubuntu 14.04.5 LTS VictordeHolland Linux 4 2018-04-11 13:44

All times are UTC. The time now is 00:00.

Wed Apr 21 00:00:52 UTC 2021 up 12 days, 18:41, 0 users, load averages: 4.33, 4.23, 3.74

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.