Best CUDA GPU for the $$

[Christenson]

I see another CUDA GPU in my future, and much better and more expensive than the cheap Pyramid GEForce210 I have running at the moment.

Assuming I have sufficient CPU and power supply (and I'll be purchasing the power supply), am I best off with a GTX560 ? Which card builder does the best job? Optimum here is either mfaktc or cudaLucas(better) or PM1-lucas(doesn't exist yet) or NFS@home(may never exist) progress per day per capital $ spent on the card, somewhere near $500. I'm thinking about operation billion digits.

Also, I'm considering running this on an older (P-4 CPU), which might not be the greatest idea. What's the minimum CPU I need to keep the GPU well fed?

Incidentally, I don't think the machine will run Windows; I'm pretty happy with Xubuntu.

[moebius]

For a Gigabyte GTX 560Ti OC you need a power supply with 500W min.
The card works with a Athlon XP Processor and 2 GB RAM , but a i7 Processor/4GB RAM is recommended by the manufacturer.


Throughput ~130 M/s for a 332 XXX XXX exponet trialfactoring from 74 to 76 bit (see attached image) on my PC (Ubuntu 10.10 , Phenom II X4 955@3,2 Ghz)

[henryzz]

From what I have read mfaktc requires much more cpu power supporting a 560 than any P4 could provide. Look at http://www.mersenneforum.org/showpos...&postcount=663 (580 i know) and other recent posts in that thread for estimates. At the very least 2 very fast cores will be needed to support it.

[Christenson]

Sounds like I should plan an new PC (running i7 sandy bridge) to help feed this thing. The extra cores can do P-1. Obviously, I'll need a 550W (or is 750W better?) PS. Is the extra $100 for 570 versus 560 worthwhile?

Word was they were going to reduce the required CPU power for mfaktc, next release, or at least throttle it so I can run it while doing other stuff on the PC with the GEForce 210 card.

[Brain]

My Core i5 750 @ 3.6GHz with GTX 560 non OC consumes 383 Watts (AC Power) (4 HDDs). My 400 Watts (DC power) power supply (energy effiecient) is sufficient. But keep in mind that especially the 12V lanes are critical. mfaktc does ~210M/s.

[moebius]

Brain is right, with four intstances of mfaktc the throughput for my card is ~230 M/s for a 332 XXX XXX exponet trialfactoring from 74 to 75.

[Christenson]

So, should I oversize the power supply? (certainly makes it easier to ensure the system operates)
And whither GTX560 versus GTX570? Is the extra $100 worth it?

[moebius]

>=550W with a minimum 12V current rating of 30 A with two 6 Pin PCIexpress supple mentray power connector should be enough.

[Christenson]

So here is the shopping list for the new GPU System with a Sandy Bridge CPU. Comments invited. I was happy with my Galaxy GeForce210, AsRock Mobo, and Antec PS, so I'll take some convincing to change the branding, but I'm still full of questions -- for example, is a dual GTX460 going to outdo a GTX570? Should I get a dead-cheap ($30) VGA GPU for the occasional display on this machine, as well as my debugging toolkit, or will a GTX440 do the job? Am I wasting my $$ getting a motherboard with 32Gig RAM capability and 3 slots that could take GPUs? How do I get 32Gig RAM in this Mobo?
I have some flexibility in the budget, so keep that in mind, and I'm happy to pay a little to avoid trouble. OS will be 64-bit Xubuntu 10.10 or later. All prices are US$$. I'm also planning on doing a little more than TF/mfaktc on this machine, possibly sieving and/or LL testing.

http://www.newegg.com/Product/Produc...82E16811147144Rosewill Destroyer ATX Case, 3 fans, $49.99
(or should I do the Antec case?http://www.newegg.com/Product/Produc...82E16811129042, Antec Three Hundred ATX case, with bottom PS, $59.99)

http://www.newegg.com/Product/Produc...82E16817371044 Antec Earthwatts EA-650 SLI-ready 650W Power Supply, $79.99

http://www.newegg.com/Product/Produc...82E16813157229ASRock P67 EXTREME4 (B3) LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 ATX Intel Motherboard, $159.99
(or am I overprovisioning, and should I get the somewhat cheaper
http://www.newegg.com/Product/Produc...82E16813157230ASRock P67 EXTREME4 (B3) LGA 1155 Intel P67 SATA 6Gb/s USB 3.0 ATX Intel Motherboard, $129.99 ???)

http://www.newegg.com/Product/Produc...82E16819115070Intel Core i7-2600K Sandy Bridge 3.4GHz (3.8GHz Turbo Boost) LGA 1155 95W Quad-Core Desktop Processor BX80623I72600K, $314.99

http://www.newegg.com/Product/Produc...82E16820104166Kingston HyperX 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model KHX1600C9D3K2/4GX, $99.98 for 2 packages and 8GB.
(Wondering if I should spring for 16 GB or 32GB; not at all clear which modules will work; these are on ASRock's QPL list)

And finally, the video cards:
The obvious choice, pictured on Galaxy's website:
http://www.newegg.com/Product/Produc...82E16814162070Galaxy 57NKH3HS00GZ GeForce GTX 570 (Fermi) 1280MB 320-bit DDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card, $334.99

I've asked Galaxy about how this one differs; besides the form factor and fan location, it seems to be the same:
http://www.newegg.com/Product/Produc...82E16814162075Galaxy 57NKH3HS4GXK GeForce GTX 570 (Fermi) 1280MB 320-bit DDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card

Finally, the 400 series cards are much cheaper, so maybe I should get two of these instead?
http://www.newegg.com/Product/Produc...82E16814162058Galaxy 60XMH6HS3HMW GeForce GTX 460 (Fermi) GC 768MB 192-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card, $169.99 with $50 mail-in rebate.


I also did some checking on a GEForce 520 versus GEForce 440 as a cheap ($79) upgrade to my AMD Phenom II six-core Xubuntu 10.10 system, which doesn't have a big enough power supply to support larger cards. I'm pretty sure I want the 440.

As with the chess positions thread, discussion is welcome...I'd much rather look silly here than waste weeks hunting tech support.

[S34960zz]

What are your plans for cooling (I may have overlooked)?

One thing I have noticed with mfaktc is that my motherboard temperature runs noticably hotter (bus traffic?) when running mfaktc compared to Prime95 (LL or DC work). This is a performance laptop with presumably well-engineered cooling, but right now I have 67 C on the 3 cores running a Prime95 DC (1 worker/3 thread, each thread its own core), 72 C on the core running mfaktc, and 74 C on the motherboard temperature sensor. Ambient is 22 C (72 F). I usually only run 2 threads on the DC worker and leave Core#2 unassigned; for some reason just that core runs about 5-6 C hotter than its peers 0, 1, 3. This is an i7-840QM with a Quadro FX 2800M. I've wondered if the heat transfer paste was not well-applied over Core#2.

So, do you have special plans for cooling your RAM, CPU, as well as venting the heat from the graphics cards? Are some motherboards known to be more performance-oriented to handle heat from super-busy busses?

I am also thinking about building a system (and may take notes from the list you've built!) but I'm leaning towards a water-cooled solution at the moment. Microway's advertisements on the back cover of Linux Journal are super-neato, too (www.microway.com) [no affiliation, just envious].

[lavalamp]

S34960zz, if you're thinking of going water cooled, you should know that it's a lot more expensive than air cooling, and involves a lot of headaches. If done right it's more effective than air cooling of course, but the time involvement to set it up is also much greater.

Good air cooling is definitely the easier way to go, and probably more reliable. For a decent air cooler you don't need to go too expensive, here's a nice big stack o' fins for $30:
http://www.newegg.com/Product/Produc...82E16835233082

You could use the stock Intel cooler, but from your choice of a K branded CPU, I'm guessing overclocking is on the cards, and the stock cooler just won't take you the places you want to go. It's worth considering if you really want hyperthreading by the way, if not then you may as well save $90 and go for the 2500K, which is exactly the same chip, but with HT disabled. They run it 100 MHz slower by default, but the multiplier is unlocked so that's just to help justify the increased price of the 2600K.

With regards to the RAM, if you're only going to be running P-1 on a couple of cores, then 4 GB is probably fine. I don't think you'll be running 32 GB since you'd need 8 GB memory modules for that and I've not seen any retailing. There are 4 GB modules though, so you could hit 16 GB if you wanted to, it's up to you really, if you think you'll use it then go for it, otherwise you might as well save your money. The third way is to hedge your bets, use only 2 of the 4 memory sockets so that if you want to upgrade later it's easy to just drop another 2 sticks in.

For 4 GB, I'd probably go with these over the Kingston modules because they have a lower latency:
http://www.newegg.com/Product/Produc...82E16820144436

And for 8 GB, GeIL again:
http://www.newegg.com/Product/Produc...82E16820144477

Both Kingston and GeIL are solid brands, here I'm differentiating on performance and price respectively.

Good PSU choice, has the 80 Plus Bronze certification, but be aware that it has only 2 PCIe power connections. By no means a show stopper as there are converters from molex power to PCIe power connectors, but if you get more than 1 graphics card and they don't include a converter, you may need to add one or two to your basket.

For the motherboard, here's a cheaper offering from MSI:
http://www.newegg.com/Product/Produc...82E16813130583

It has two PCIe 16x slots although one is only 8x electrical, but that's fine for crunching, there's a ridiculous amount of bandwidth in those PCIe lanes and I don't think any GPGPU program even comes close to using it. The down side is that there's only one PS/2 port if you're using a PS/2 KVM, if not then I guess it doesn't matter.

When you're crunching with graphics cards, they can get pretty loud! They usually have pretty decent, but compact, cooling solutions. To compensate, they run their fans at 15 trillion rpm. If that will bother you then you can of course spend more money on aftermarket GPU coolers too. The advantages of these are lower temps and less noise, but the disadvantages are that they tend to be 3 slot (rather than 2 slot) coolers, and they don't exhaust the air outside of the case.

For example:
http://www.arctic.ac/en/p/cooling/vg...us.html?c=2182