Message boards :
Number crunching :
Freeing CPU cores
Message board moderation
Author | Message |
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bill Send message Joined: 16 Jun 99 Posts: 861 Credit: 29,352,955 RAC: 0 |
Has anyone posted the exact meaning of 'freeing up a cpu core' in relation to gpu usage, and the where and how to do so? And since there is more than one way to do it, which would be the best/easiest/fastest way to do it, in such a way that a newb would understand it? A faq perhaps? |
Tazz Send message Joined: 5 Oct 99 Posts: 137 Credit: 34,342,390 RAC: 0 |
Has anyone posted the exact meaning of 'freeing up I 'free up a core' in the local Preferences>processor usage tab. "On multiprocessor systems, use at most ___% of the processors." I set mine at 90% and it crunches on 7 cores and leaves the 8th free. 75% on a 4 core system will leave 1 free </Tazz> |
bill Send message Joined: 16 Jun 99 Posts: 861 Credit: 29,352,955 RAC: 0 |
Yes, but is that for ATI or NVIDIA or is there a difference between the two that newbs should be aware of. Mine are set. I'm looking for something to point to when a newb comes in that can be pointed at to answer their questions while inflicting the minimum of pain on them. |
Mike Send message Joined: 17 Feb 01 Posts: 34253 Credit: 79,922,639 RAC: 80 |
Yes, but is that for ATI or NVIDIA or is there a difference Works for both. 90% doesn`t free a full core. On a 8 core the correct settings is 86% on a quad 75%. With each crime and every kindness we birth our future. |
juan BFP Send message Joined: 16 Mar 07 Posts: 9786 Credit: 572,710,851 RAC: 3,799 |
Yes, but is that for ATI or NVIDIA or is there a difference The unwrited rules is... You need to free 1 core if you have a AMD CPU and want to crunch on the GPU (ATI or NV) even if you run only MB, if you run AP you need to add +1 free core per GPU WU (AMD or Intel CPU). To be sure the % to use just do the following math: 100*(1-(free cores needed)/(processor number of cores)) On I5 or Quad a processor number of cores = 4 On I7 processor number of cores =8 without HT or 4 with HT enabled Same works with AMD or other Intels CPU´s. It´s clear now? |
William Send message Joined: 14 Feb 13 Posts: 2037 Credit: 17,689,662 RAC: 0 |
With 8 cores one core is 12.5. Anything less than 100 will free one core. (allow 7 tasks) 88 will free one core. (7 tasks) 87.5 - since it's allow' One core not used - 7 tasks 87 will free two cores. 80 - 6 out of 8 cores in use 75 - still 6 74 - 5 70 - 5 So, for ease of editing when you have 8 cores: 50 - 4 cores used 70 - 5 cores used 80 - 6 cores used 90 - 7 cores used And for a quad: 50 - 2 cores 75 - 3 cores (you could use 80 too) A person who won't read has no advantage over one who can't read. (Mark Twain) |
Mike Send message Joined: 17 Feb 01 Posts: 34253 Credit: 79,922,639 RAC: 80 |
edited With each crime and every kindness we birth our future. |
William Send message Joined: 14 Feb 13 Posts: 2037 Credit: 17,689,662 RAC: 0 |
On a AMD CPU 88% isn`t enough. 86 should be freeing two cores - if you have more than 6 CPU tasks running, you've found a bug. A person who won't read has no advantage over one who can't read. (Mark Twain) |
Mike Send message Joined: 17 Feb 01 Posts: 34253 Credit: 79,922,639 RAC: 80 |
[quote] With each crime and every kindness we birth our future. |
Tazz Send message Joined: 5 Oct 99 Posts: 137 Credit: 34,342,390 RAC: 0 |
On a AMD CPU 88% isn`t enough. My FX 8150 is set to use 90% and it's crunching 7: 08/08/2013 11:13:54 AM | | max CPUs used: 7 One core should be enough for 2 GTX 560 with 2 wu's each, shouldn't it? The work times are similar to the GTX 560 in my other machine that has a free core (Phenom 9650) and 2 wu's. -- ONLY MB btw. </Tazz> |
William Send message Joined: 14 Feb 13 Posts: 2037 Credit: 17,689,662 RAC: 0 |
On a AMD CPU 88% isn`t enough. Well what BOINC does and what Windows does are different things. 88 will tell boinc to only run 7 tasks, 87 drops it to 6 tasks. Those 7 cores will be fully used (depending on app) the remaining core then takes the normal load - so yes, technically not a full core is available. For most people freeing most of a CPU core is enough. A person who won't read has no advantage over one who can't read. (Mark Twain) |
Mike Send message Joined: 17 Feb 01 Posts: 34253 Credit: 79,922,639 RAC: 80 |
[quote] With each crime and every kindness we birth our future. |
Mike Send message Joined: 17 Feb 01 Posts: 34253 Credit: 79,922,639 RAC: 80 |
edited With each crime and every kindness we birth our future. |
William Send message Joined: 14 Feb 13 Posts: 2037 Credit: 17,689,662 RAC: 0 |
On a AMD CPU 88% isn`t enough. Rule of thumb is one core per card. - You might want to try and free another core. We've gone horribly offtopic by the way which is quite impolite to a new user. Where's a moderator when you need one... A person who won't read has no advantage over one who can't read. (Mark Twain) |
Mike Send message Joined: 17 Feb 01 Posts: 34253 Credit: 79,922,639 RAC: 80 |
[quote] With each crime and every kindness we birth our future. |
cov_route Send message Joined: 13 Sep 12 Posts: 342 Credit: 10,270,618 RAC: 0 |
I suspect what I'm doing is different from almost everyone else: I use the anonymous platform, not stock apps, so I can use app_info.xml. In BOINC my settings are to use 100% of the CPU. In app_info, for astropulse I set <avg_ncpus> and <max_ncpus> to 1, so it sets aside a core for each GPU job when they run. For multibeam I don't free a core, I use the command line settings: -cpu_lock -instances_per_device 2 -gpu_lock which set the GPU jobs to run on an assigned single core. For my Phenom II, at least, that works as well as idling a core. |
William Send message Joined: 14 Feb 13 Posts: 2037 Credit: 17,689,662 RAC: 0 |
To answer the original question: if anyone writes a FAQ entry I'll be delighted to post it in the Lunatics FAQ section. A person who won't read has no advantage over one who can't read. (Mark Twain) |
_ Send message Joined: 15 Nov 12 Posts: 299 Credit: 9,037,618 RAC: 0 |
I am just days away from trying to get my first AMD graphics card going on a rig. Is freeing up a core something I only need to worry about for AMD cards? So far with NVidia cards, my graphics card task usually says something like (1 NVIDIA GPU + 0.04 CPUs) |
skildude Send message Joined: 4 Oct 00 Posts: 9541 Credit: 50,759,529 RAC: 60 |
try running your nvidia card with a free core for a few WU cycles see if it improves(decreases) your GPU WU completion times In a rich man's house there is no place to spit but his face. Diogenes Of Sinope |
Raistmer Send message Joined: 16 Jun 01 Posts: 6325 Credit: 106,370,077 RAC: 121 |
Did you try the same for AP and failed or just didn't try ? AP and MB share GPU/CPU lock code so if it works for MB it should work for AP too (in theory and in latest builds) SETI apps news We're not gonna fight them. We're gonna transcend them. |
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