Message boards :
Application Code Discussion :
GPU app teaser
Message board moderation
Previous · 1 . . . 3 · 4 · 5 · 6 · 7 · 8 · 9 . . . 19 · Next
Author | Message |
---|---|
Send message Joined: 30 Aug 07 Posts: 2046 Credit: 26,480 RAC: 0 |
Also, I can raise the workunit-per-cpu limit. What would be a good value? I think one of the recent updates to the BOINC server code allows for a separate daily WU queue for GPUs. I'll do a little looking into it and if thats the case then we can give the GPUs a 10k daily limit without touching the other one. |
Send message Joined: 25 Nov 07 Posts: 25 Credit: 54,443,893 RAC: 0 |
Sounds like a good idea to me. |
Send message Joined: 28 Aug 07 Posts: 31 Credit: 86,152,236 RAC: 0 |
I think one of the recent updates to the BOINC server code allows for a separate daily WU queue for GPUs.Well, it may (i don't know). But I known that even latest BOINC client 6.6.7 still doesn't recognize GPUs (means both nVidia and ATI/AMD GPUs), only CUDA capable devices. (not only) MW would benefit a lot from support of ATI GPUs under BOINC, especially those capable of double precision... BOINC Project specifications and hardware requirements |
Send message Joined: 26 Jul 08 Posts: 627 Credit: 94,940,203 RAC: 0 |
avg_ncpus set to 0.1 You should not set max_ncpus to another value than exactly 1. It is the maximal number of cores a single WU can use. As the app is single threaded it can't use more than a core. That the WUs are taking the same time no matter how many WUs are running concurrently is perfectly normal. There is probably a slight increase in efficiency (maybe 5%) if two WUs are running compared to a single one. The reason is that you can carry out the few calculations still necessary on the CPU in the time when another WU is waiting for the GPU. But more than two WUs won't help more (but don't hurt either). You will have a throughput of about one WU per 9.x seconds either way on a HD4870. But there is a limit on the number of concurrent WUs. If you try to run more than 12-16 (~30) WUs on a 512MB (1GB) card, it starts to get slower and finally breaks, because there is not enough memory on the card. In the moment there is no mechanism to check for available RAM on the card. You shouldn't set avg_cpus to very low values to avoid this situation. PS: I guess the credit situation gets better if the limits are lifted by Travis ;) |
Send message Joined: 12 Nov 07 Posts: 2425 Credit: 524,164 RAC: 0 |
I think you need to make sure that there is plenty of work to do if many of these are ran. Might be time for server #2. Doesn't expecting the unexpected make the unexpected the expected? If it makes sense, DON'T do it. |
Send message Joined: 12 Nov 08 Posts: 26 Credit: 1,542,686 RAC: 0 |
max_ncpus back to "1". avg_ncpus set to 0.25. If I keep the default value of 0.50, I have only three WU running at the same time : two optimized MW and one World Community Grid. With avg_ncpus to 0.25 I have four workunits (two for each project) Travis > thank you very much for your answer about the credits, it's a very good news. For maximum number of units per core, I can say that : with a Core2Duo and a HD4850 512Mo, I crunched 2000 workunits in 6 hours (with no other projet running at the same time, so the CPU wasn't at full use). So 4.000 workunits per core and day will be enough for this configuration (my computer is working "only" 12 hours per day or so, so 4.000 WU per core and day is the very, very maximum). I don't know how many workunits can be crunched with another model of ATI. Cluster > If I understand correctly, your optimization uses "only" one core at a time, is that right ? Is it possible to use more core, so we can use only Milkyway on one computer with more than one core ? Do you need something special to help you for your tests ? PS : during this writing I reached my 2.000 workunits limit - later than before, probably because I tried avg_ncpus to 0.10 ... Star Wars BOINC Team |
Send message Joined: 8 Dec 07 Posts: 60 Credit: 67,028,931 RAC: 0 |
max_ncpus back to "1". With the gpu, I can crunch 16 @ a time with the i7, so 10k limit per core, or 80,000 in my case, would be a more realistic than 4000. |
Send message Joined: 26 Jul 08 Posts: 627 Credit: 94,940,203 RAC: 0 |
Cluster > If I understand correctly, your optimization uses "only" one core at a time, is that right ? Is it possible to use more core, so we can use only Milkyway on one computer with more than one core ? The goal is actually to use not a full core (or even more), but maybe only 10% of a core or so. This way your CPU would be free to crunch something else. If it is really wanted I could put in support for simultaneous crunching of MW on GPU and CPU. But this would have a low priority on my list. |
Send message Joined: 26 Jul 08 Posts: 627 Credit: 94,940,203 RAC: 0 |
With the gpu, I can crunch 16 @ a time with the i7, so 10k limit per core, or 80,000 in my case, would be a more realistic than 4000. But the throughput is still be one WU every 9 seconds or so with a HD4870. It is not getting faster with more concurrent WUs. So with a HD4870 a limit of 10,000 WUs a day would be enough as long there is no multi GPU support implemented (or massive overclocking involved). I would say 10,000 WUs per host and day are needed now. When multiple cards are working and/or newer GPUs are available, this needs to be raised again. |
Send message Joined: 6 Apr 08 Posts: 2018 Credit: 100,142,856 RAC: 0 |
Cluster > If I understand correctly, your optimization uses "only" one core at a time, is that right ? Is it possible to use more core, so we can use only Milkyway on one computer with more than one core ? What I would like to see is the ability to use my Nvidia in MW. I know you are using an ATI since it is faster, but I only have the Nvidia which I'd be interested in transferring from crunching on GPUGRID to MW. |
Send message Joined: 26 Jul 08 Posts: 627 Credit: 94,940,203 RAC: 0 |
Cluster > If I understand correctly, your optimization uses "only" one core at a time, is that right ? Is it possible to use more core, so we can use only Milkyway on one computer with more than one core ? Afaik, there is already a student starting to work on a CUDA app. As this is easier to work with, I guess we could see some results soon ;) But don't expect times much below 25s per WU for nvidias GTX line. And older ones won't work at all (lack of double precision units). |
Send message Joined: 6 Apr 08 Posts: 2018 Credit: 100,142,856 RAC: 0 |
What I would like to see is the ability to use my Nvidia in MW. I know you are using an ATI since it is faster, but I only have the Nvidia which I'd be interested in transferring from crunching on GPUGRID to MW. 25 secs? Blimey, hurry up student :) |
Send message Joined: 26 Jul 08 Posts: 627 Credit: 94,940,203 RAC: 0 |
25 secs? Blimey, hurry up student :) But that is soooo slooooow compared to the less than 10 seconds on ATIs HD4870 ;) |
Send message Joined: 12 Oct 07 Posts: 77 Credit: 404,471,187 RAC: 0 |
25 secs? Blimey, hurry up student :) 25 sec is good enough for me, hurry up student :-) |
Send message Joined: 27 Aug 07 Posts: 647 Credit: 27,592,547 RAC: 0 |
25 secs? Blimey, hurry up student :) Rats, I need a new graphics card finally! Lovely greetings, Cori |
Send message Joined: 8 Dec 07 Posts: 60 Credit: 67,028,931 RAC: 0 |
With the gpu, I can crunch 16 @ a time with the i7, so 10k limit per core, or 80,000 in my case, would be a more realistic than 4000. oh, i agree with that too. the turn around time for the gpu app was about 2 1/2 minutes. i've been running the op app this week and it's crunching 8 wu's in 6 minutes since the .19's came out, so that limit needs to go much higher as well. |
Send message Joined: 26 Jul 08 Posts: 627 Credit: 94,940,203 RAC: 0 |
With the gpu, I can crunch 16 @ a time with the i7, so 10k limit per core, or 80,000 in my case, would be a more realistic than 4000. It should be enough for your i7, as the current limit is 1,000 WUs per day and core/thread. That means on your i7 you have actually 8,000 WUs a day to play with. You won't come close to that limit with the CPU alone, but it will last for 21 hours a day only on the GPU ;) |
Send message Joined: 30 Aug 07 Posts: 2046 Credit: 26,480 RAC: 0 |
Cluster > If I understand correctly, your optimization uses "only" one core at a time, is that right ? Is it possible to use more core, so we can use only Milkyway on one computer with more than one core ? Yeah hopefully within the next week or two we'll have an alpha CUDA application for you guys to crash :D |
Send message Joined: 12 Apr 08 Posts: 621 Credit: 161,934,067 RAC: 0 |
Yeah hopefully within the next week or two we'll have an alpha CUDA application for you guys to crash :D Well, I have one GTX 280 and 2 GTX 295s ... start your engines ... Of course we will need a setting on the site to get only CPU work, only CUDA work ... or both ... |
Send message Joined: 2 Jan 08 Posts: 23 Credit: 495,882,464 RAC: 0 |
Yeah hopefully within the next week or two we'll have an alpha CUDA application for you guys to crash :D It's effectively important to have both options. |
©2024 Astroinformatics Group