[quotE=On Feb 5,2013;327610]All exponents below [B][COLOR="DarkRed"]26,083,693[/COLOR][/B] have been tested and double-checked.
All exponents below [B][COLOR="Indigo"]44,250,841[/COLOR][/B] have been tested at least once.

[U]Countdown to testing all exponents below M([B][COLOR="Blue"]xxxxxxxx[/COLOR][/B]) once: 52,242[/U]

Countdown to proving M([COLOR="Purple"]30402457[/COLOR]) is the [COLOR="Purple"]43[/COLOR]rd Mersenne Prime: 9,399
Countdown to proving M([COLOR="MediumTurquoise"]32582657[/COLOR]) is the [COLOR="MediumTurquoise"]44[/COLOR]rd Mersenne Prime: 50,453[/QUOTE]

All exponents below [B][COLOR="DarkSlateBlue"]26,114,633[/COLOR][/B] have been tested and double-checked.
All exponents below [B][COLOR="Indigo"]44,250,841[/COLOR][/B] have been tested at least once.

[U]Countdown to testing all exponents below M([B][COLOR="Blue"]57885161[/COLOR][/B]) once: 39,714[/U]

Countdown to proving M([COLOR="Purple"]30402457[/COLOR]) is the [COLOR="Purple"]43[/COLOR]rd Mersenne Prime: 4,641
Countdown to proving M([COLOR="MediumTurquoise"]32582657[/COLOR]) is the [COLOR="MediumTurquoise"]44[/COLOR]rd Mersenne Prime: 39,834"

I just turned over 4 THz-days in P-1 under GPU72. (PrimeNet lists a couple of hundred GHz-days more.) I guess when GPU P-1 comes into its own that won't seem like such an accomplishment.

I am trying to imagine the GIMPS box of the not-too-distant future. It really seems that the CPU will only be there for housekeeping and won't really need that much crunch ability. What would be needed is a motherboard with LOTS of PCIe slots, appropriate chips to keep them at x16 speed, a very beefy PSU, and excellent cooling.

That suggests that my current board (Asus Crosshair V Formula-Z) could run at least 3 GPUs, but could be happy with a (cheap) non-FX quad core CPU. It would only be able to do PCIe 16x8x8, though. (Of course, such a thing would likely [U]require[/U] water cooling, at least for the GPUs.)

Does anyone have ideas about what the optimal GPU-centric GIMPS platform would be? I'm thinking in terms of currently available hardware such as motherboards, CPUs, RAM, etc.

The most unfortunate thing is that most of our gpu software works best (or only, in some cases) with the Cuda, not OpenCL. I say that not because I love ATI (<3 nvidia) but because I've seen a lot of boards set up for the crossfire config with 4 gpus, but have very seldom seen any good nvidia boards with more than 3.

I think the heat from 4 high end ati cards would be realy extreeme though - I have an overspec 480 and an overspec 580 in my watercooled rig, and require 2 14cm x 42cm radiators. There are 6 14mm fans attached to those radiators (3 each) and while the whole rig is nearly silent the amount of heat it generates ensures that my bedroom windows are open all winter long. I should probably put the computer in the basement and use it to heat the house - I may have to at the peak of summer this year.

One could get better cooling solutions (in my case, I had one radiator for years, and added a second one - I wouldn't have purchased two at the same time when phobya also makes a 42x42 version) but I think with 4 high end cards you would actually need a mini fridge to keep up with the heat output, or something exotic with a lot of surface area and at least 2 pumps.

hmmm a quad-590-SLI that would make 8 GPU right? LN cooling, for sure.

[QUOTE=Aramis Wyler;339542]... but I think with 4 high end cards you would actually need a mini fridge to keep up with the heat output, or something exotic with a lot of surface area and at least 2 pumps.[/QUOTE]

When I was working with SETI there was a fellow in the GPU Users' Group who used a small aquarium cooler in his liquid cooling loop.

[QUOTE=Aramis Wyler;339542]
I think the heat from 4 high end ati cards would be realy extreeme though -...[/QUOTE]

Have you considered the "open-bench" style?

EDIT: Would make a good room heater maybe.
EDIT2: [URL]https://www.youtube.com/watch?v=O5aR-hUIY6A[/URL] Trollololol... look at the top of the room!

[QUOTE=kracker;339576]... look at the top of the room![/QUOTE]

LOL... In Canada that would be a very profitable "Grow Show"....

[QUOTE=chalsall;339577]LOL... In Canada that would be a very profitable "Grow Show"....[/QUOTE]

They have them in the USA too. I wonder how much he pays for his electric bill.

[QUOTE=Chuck;339553]When I was working with SETI there was a fellow in the GPU Users' Group who used a small aquarium cooler in his liquid cooling loop.[/QUOTE]

Aquariums themselves (even aside from their pumps) are pretty entertaining in the water cooling environment because with a reservoir like that the glass sides of the aquarium constitute so much surface area that they start making remarkably good radiators. I'm not seen anyone successfully use a water-filled aquarium as a cooling reservoir (though I'm sure someone has!) but the mineral oil filled aquariums radiate enough heat out for submerged systems. I hear that capillary action makes them pretty miserable to actually use though, unless they're headless.

I have a smallish (10 gallon) aquarium that's not being used right now, but I've never been moved to actually try to use it. I'd do it if it meant I could keep tropical fish in there, but I don't want their biology in my computer any more than they want my toxins in their environment.

[QUOTE=Aramis Wyler;339592]Aquariums themselves (even aside from their pumps) are pretty entertaining in the water cooling environment ...[/QUOTE]

I don't know if my previous post was misleading — the fellow in the SETI GPU Users' Group was using a small refrigerating unit (an aquarium chiller) in the loop, not an actual aquarium tank.

It was clear. Just really, aquariums do fun things when paired with watercooling. Some of those aquariums pumps though are a good buy too for the thrust they put out, and they're often submersible which cuts down the noise (vibration) a lot.