CPU vs GPU
21 Nov 2013 11:41:34 UTC
Topic 197280
(moderation:
Hi, is there any option where I can select for example:
1. use 25% of CPU
2. use 90% of GPU
... or something similar, and I haven't seen it? :D
There's one "use GPU continously" or "use GPU acc. to settings", but if I select in settings to use 25% of CPU, does that mean it also uses 25% of GPU, or not?
CPU vs GPU
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1. Yes, in your Computing preferences the setting "On multiprocessors, use at most xx% of the processors" limits the number of cores Boinc can use to process tasks.
2. No, it's all or nothing for the GPU usage.
another question: I have a
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another question: I have a Pentium (4, I guess) Celeron at 1,6Ghz and I was thinking of buying a GeForce GTX 760. The comp is about 10 years old. Would it be ok to make that combination? Wouldn't the GTX be "too" powerfull for the CPU?
RE: buying a GeForce GTX
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Pls check your mainboard, GTX 760 requires a pci-e 2.0 slot minimum, better pci-e 3.0
It's possible that your board has pci only ...
RE: another question: I
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Hi John,
Welcome to Einstein@Home. We hope you enjoy your stay.
It's great to want to put old hardware 'back into service' and also upgrade it, but there are a number of potential issues you have to be mindful of. Alex has already highlighted one of these.
In addition to that one (no PCI-e slot for the GPU), your machine would be unlikely to have a PSU (power supply unit) of sufficient capacity to handle the card. You would also be unlikely to have enough memory. Even if you were to try to run the machine 'as is' and you did have enough memory for CPU tasks, it would be incredibly slow and wasteful of electricity for the output you might be able to get.
If you were prepared to 'get your hands dirty' you might be able to upgrade enough parts to turn it into quite a decent crunching box. The biggest question to ask is whether or not your current case could take a standard ATX or mATX motherboard and a standard PSU? If so, for about $250 or so, you could purchase new motherboard, PSU, CPU and RAM and end up with a machine that would handle your proposed GPU very nicely. You would be reusing your existing case and CD/DVD drive and hopefully your HDD if it was suitable.
If you wanted to consider this but didn't feel confident, I'm sure there would be a number of people willing to give advice and instructions about what to do.
Best of luck with whatever you decide to do.
Cheers,
Gary.
Hi Gary, many thanks for the
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Hi Gary, many thanks for the details.
I know it's quite triky to find the right combination for the MB, RAM, CPU (a new one), a PSU and a case. I guess that's why putting back to work an old computer is sometimes quite a challenge. I have some homework to do :)
Cheers!
As an alternative, I'm
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As an alternative, I'm curious what would a computer config. look like, judging from the perspective of components' quality/price/efficiency?
There were a few configurations here that had an i5k (or i7k), 4gb ram, a 150$ MB (motherboard) and 1 (or even 2) nvidia gtx 660. From my estimate, that's about 700-800$. Would this b close to 100% price/power/efficiency report? If not, how would a config that aimes for 100% look like?
RE: As an alternative, I'm
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It depends on what you're trying to maximise; I'd say that for efficiency generally go for the latest-generation CPU/GPU, for quality pay a little more and for price go for AMD rather than Intel.
For e@h specifically, gaming-style setups will churn out the results but at the cost of efficiency. On here, point-scoring vs. cost seems to be all about middle of the pack GPUs, low-end CPUs and good motherboard chipsets. From that perspective, your configurations look good but you could save money on the CPU (unless you have other reasons for needing a multi-core monster).
RE: ... There were a few
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I presume you are asking for suggestions that give you the best possible crunching power and efficiency for the lowest possible price. The answer to that (as always) is - it depends :-).
You first need to decide which particular science run you are interested in. In your earlier message, when you talked about adding a reasonably powerful GPU to a quite old system, I assumed you were most interested in GPU crunching using either the Arecibo radio telescope data or the Perseus arm survey (PAS) using the Parkes radio telescope data. If that's the aim, you really can get away with quite a low cost CPU to support the GPU. If you're more interested in Gravity Wave (LIGO data) or Gamma Ray Pulsar (Fermi satellite) searches, you need only CPU power, as there (probably for a while anyway) is no GPU app in production for those searches.
For a GPU cruncher, you would need a basic motherboard (H81 chipset $40 - $70), a basic CPU, eg Pentium G3220 (~$70), RAM 2x4GB DDRIII ($70-$80) and a PSU - good brand around 500W and 80+ certified (~$60). The total of the above should be around $250 or so. If you wanted a quad (or higher) core CPU, the cost would go up quite a bit without making any real difference to the GPU output.
The GPU is your choice and would be on top of the above. If you chose a GTX660, it would probably cost around $200-$250 and for quite a bit less money you could get an AMD HD7850 (cheap because of the new models that are out now). I'm running a couple of HD7850s (2 separate hosts) and they have RACs around 65K. One is powered by an old Phenom II x4 and the other by an i5-3570K. The one in the Phenom II x4 host is actually performing slightly better, which surprised me. In both cases the GPUs crunch 4 tasks in parallel in around 5 hours with 2 CPU cores running CPU tasks and the other two supporting the GPUs. Because of the greater difficulty in cooling, the greater expense of higher spec'ed parts, and the potential to lose performance per GPU, I tend to avoid using more than 1 GPU per host.
For your old Celeron 1.6GHz, can you give the specs for the case, PSU, optical drive and HDD, if you would like to consider upgrading it, thanks?
Cheers,
Gary.
Just a small gotcha to be
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Just a small gotcha to be careful of - the old HDD and optical drives will use IDE interfaces, but new motherboards will be predominantly SATA. Not insurmountable, but something to check.
I have a PC with 2 SATA disks
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I have a PC with 2 SATA disks and an IDE/ATAPI DVD writer. Since this is no longer working, I bought a new one, but I could only find a SATA. OK, i bought an Advance small printed board which connects IDE to SATA or SATA to IDE. I thought to have solved my problem, but the new SATA DVD writer needs also a SATA power cable, which my older power supply does not have. So I gave up and use the DVD writer of my newer HP laptop.
Tullo