Posts by archan127

1) Message boards : Projects : Performance issues since I added cosmology@home (Message 67932)
Posted 21 Feb 2016 by archan127
Post:
That can be complicated if you use multithreaded apps.

For normal single threaded CPU tasks, which most BOINC project apps are, I will only allow the BOINC manager to use 3 of my 4 processors, and the GPU task will use the remaining core. If it is a multithreaded app, the app will use as many cores as you have allocated to the BOINC client, I think. If you don't restrict how many cores it can use, it will use all of them. With milkyway@home, if I restrict the number of processors to three, and then update the project, when I run the multithreaded app there, it will only use 3 CPU cores, leaving 1 core available to help crunch the GPU task.

If you look at the GPU tasks running in the BOINC manager, they will tell you how much of a CPU core the app uses. For example, for Einstein@home, most of the the GPU apps will use 0.2 CPU + 1 GPU which means it should only use 20% of the CPU core and the GPU. SETI@home uses 0.04 CPU + 1 GPU for the multibeam app, which means it should only use 4% of the CPU and the GPU. POEM@home actually uses 1 CPU + 1 GPU for the nVidia app, so it will take a whole CPU core and the GPU.

I'm not sure how the cosmology@home apps work since I haven't run the new ones yet, but I am assuming since they are multithreaded they would work the same as in milkyway@home. By restricting the number of cores BOINC can use, you can leave a core available for GPU tasks.

Also, I have found with the nVidia card, CUDA apps use less CPU cycles and OpenCL apps use more CPU cycles. When I run the nVidia astropulse app for SETI@home, it uses an entire CPU core, but the multibeam CUDA app barely uses the CPU at all.

Go to the computing preferences in the options or tools menu, and see the option: Use at most ___ % of the CPUs, you can control how many CPUs BOINC will use.

http://boinc.berkeley.edu/wiki/Local_preferences
2) Message boards : Projects : Performance issues since I added cosmology@home (Message 67926)
Posted 20 Feb 2016 by archan127
Post:
Yes...I have 4 cores and all the cosmology@home apps use 4CPUs. That's the reason. But would that explain that it changes settings on my video card? as long as cosmology@home runs I cannot change clock settings in afterburner.


GPU tasks do require at least "part" of a CPU core. I have come to the realization that with my 4 core CPU, if I'm also running a GPU workunit (usually with my nVidia card), such as SETI or Einstein, I allocate a whole core just to the GPU task running... I also have an Intel GPU and will allocate a whole CPU to that if its running a task as well. So I end up running 2 CPU tasks, and 2 GPU tasks (1 nVidia, 1 Intel) and leave 2 CPU's for the GPU tasks to use.

By using 4 CPU cores for cosmology, and running a GPU task, you are essentially "starving" the GPU of CPU cycles it needs to complete a task, causing it to take longer to process a task. Perhaps it downclocks the GPU because its running too fast for the CPU to keep up with limited CPU clock cycles?

As a good rule of thumb, for me at least, is for every GPU task I run, I count on using 1 CPU core also for that task.
3) Message boards : BOINC client : Problems with FreeBSD BOINC client 7.2.33 WCG certificate error (Message 58430)
Posted 5 Dec 2014 by archan127
Post:
I am currently using FreeBSD x86_64 10.1 stable running the BOINC client version 7.2.33. As recently as November 23, 2014 I was able to connect to the World Community Grid to crunch workunits. I just recently updated my version of Firefox to 34, which also involves updating the certificate store ca-root-nss.crt. Now I am unable to connect to WCG without it throwing the error Scheduler request failed: Peer certificate cannot be authenticated with given CA certificates. So I enabled the <http_debug> flag and got the whole picture:

Thu Dec 4 18:04:26 2014 | World Community Grid | update requested by user
Thu Dec 4 18:04:29 2014 | World Community Grid | Sending scheduler request: Requested by user.
Thu Dec 4 18:04:29 2014 | World Community Grid | Not requesting tasks: "no new tasks" requested via Manager
Thu Dec 4 18:04:29 2014 | World Community Grid | [http] HTTP_OP::init_post(): https://scheduler.worldcommunitygrid.org/boinc/wcg_cgi/fcgi
Thu Dec 4 18:04:29 2014 | World Community Grid | [http] [ID#1] Info: Connection 1 seems to be dead!
Thu Dec 4 18:04:29 2014 | World Community Grid | [http] [ID#1] Info: Closing connection 1
Thu Dec 4 18:04:29 2014 | World Community Grid | [http] [ID#1] Info: Connection 0 seems to be dead!
Thu Dec 4 18:04:29 2014 | World Community Grid | [http] [ID#1] Info: Closing connection 0
Thu Dec 4 18:04:29 2014 | World Community Grid | [http] [ID#1] Info: Hostname was NOT found in DNS cache
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: Trying 198.20.8.246...
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: Connected to scheduler.worldcommunitygrid.org (198.20.8.246) port 443 (#4)
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: successfully set certificate verify locations:
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: CAfile: /usr/local/share/certs/ca-root-nss.crt
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: CApath: none
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: SSLv3, TLS handshake, Client hello (1):
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: SSLv3, TLS handshake, Server hello (2):
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: SSLv3, TLS handshake, CERT (11):
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: SSLv3, TLS alert, Server hello (2):
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: SSL certificate problem: self signed certificate in certificate chain
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] [ID#1] Info: Closing connection 4
Thu Dec 4 18:04:30 2014 | World Community Grid | [http] HTTP error: Peer certificate cannot be authenticated with given CA certificates
Thu Dec 4 18:04:31 2014 | World Community Grid | Scheduler request failed: Peer certificate cannot be authenticated with given CA certificates

So there is a self-signed certificate in the chain. Does anyone have any advice on where to go to help resolve this issue... i.e. WCG, BOINC, FreeBSD, Mozilla? I'm a little confused. Thank you all in advance!

Jeremy
4) Message boards : Questions and problems : Starving the GPU with inadequate CPU resources? (Message 54248)
Posted 23 May 2014 by archan127
Post:
Thank you both for your responses.

I run Einstein GPU along with 4 CPU units (quad-core i5) without any problems, do you know what's keeping you from using all allocated cores? Memory?


I prefer to keep my computer running BOINC with 3 cores (3 CPU workunits) plus the GPU using a little bit of the unallocated core for its workunit. I've found it snappiest, since I am on the computer often using Office or using the internet while I'm crunching. If I do leave the computer for extended periods, I will usually turn it up to 4 CPUs.

The problem is right now I'm running a primegrid@home genefer world record NVidia task using OpenCL and it really likes the CPU. It says that it only takes 0.0484 CPUs + 1 NVIDIA GPU but when I run Windows task manager it is fully utilizing the CPU almost 100% of the time. If I'm not around to manually control the CPU workunit queue, it will run 4 CPU workunits plus the GPU workunit. But if I do that it really throttles down the GPU workunit from 24% down to 2 or 3%. It is already going to take 260 hours to finish that workunit, I don't want to slow it down any more than that.

I suppose I could modify the init_data.xml file and tell it to go ahead and use the full CPU, it would make controlling the queue much easier, but I don't like to mess with those allocations. I'm of the mindset that the program developers and project administrators know what works best for their projects, not me. And I have found in some apps messing with the CPU allocation can actually slow the GPU down, not speed it up.
5) Message boards : Questions and problems : Starving the GPU with inadequate CPU resources? (Message 54218)
Posted 21 May 2014 by archan127
Post:
This question has probably been asked several times. But I would like some clarification on how CPU allocation works when GPU computing is involved.

I have a 4 core computer and use a NVidia GPU (the GPU is dedicated to BOINC projects only) to compute work units as well. I normally like to set the BOINC client to use 3 CPUs to crunch 3 CPU based workunits (such as Rosetta, NFS, yoyo, or climateprediction.net, etc.) I also usually crunch 1 GPU based workunit at a time, most of the time constantly, warm weather permitting.

I know that if a GPU based workunit requires a large portion of a CPU resource (such as an Einstein@home workunit requiring 0.45% of a CPU), it can cut down the number of CPU workunits crunching to 2 (using the above 3 CPU allocation). But how about the workunits that require small CPU resources? (such as seti@home CUDA based workunits are usually pretty small CPU resource requirements, or primegrid). These workunits usually require 0.04% of a CPU. When I crunch these GPU workunits with the 3 CPU workunits, it does not cut the number of CPU workunits down to 2.

My question is, if I am crunching 3 CPU workunits and using the GPU to crunch a workunit and it only requires, say 0.04% of a CPU, am I starving the GPU of CPU resources by limiting the BOINC client to 75% (or 3 CPUs)?

Thank you for your time.



Copyright © 2024 University of California.
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.