W/C for 4 x 295GTX

Hello folks,

I'm trying to build a dedicated folding (plus a little gaming) rig. As of now I'm planning to buy Asus mobo with 7xPCI-E and plug 4 x 295GTX in there. As this beast will sit in my bedroom, water cooling sounds like a great idea. However, there is a problem: most water blocks I could find for 295GTX have nozzles at the side, which makes installing 4 of them right next to each other impossible. Are you guys aware of any water block that would allow me to make this happen? On a more general note, what would be your recommendations when building this kind of a rig?

Thanks!

P.S. This will be built from scratch, so I can buy whatever components are needed (case, WC system etc). Budget for this whole endeavor is around $4K, but the hardware itself will eat up a good chunk, so I'd rather not go for ultra-pricey options in WC.

First thing, 4k for this project is not nearly enough. You're talking 1800 in GPU's alone and another 400 for the motherboard. A case to hold this kind of gear would be 300.00 or more. That's 2500 without a CPU, memory, PSU(s) (you'd probably need a couple), drives and we haven't even talked watercooling yet that would run 1500 or more, etc.

You are pretty limited to full coverage waterblocks for 295's due to the dual GPU's. You do realize you could SLI two of the four and the other two are just independant cards...right? Connecting them all together is easy for a block like this:

http://www.performance-pcs.com/cata...=product_info&cPath=240_582&products_id=25949

When you remove the stock cooler you replace he double slot PCI with a single. You use a normal barb on the top of the first card and bottom of the last and connect the rest with something like this:

http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=342&products_id=24980

You need at least two good 3x120 rads or more, one for each two GPU's and if you want to cool the CPU, that would be another plus the block. About the only case that can handle all of this (Special motherboard, rads, two PSU's) is a Mountain Mods and you're talking 550. For what you are looking to do, you have to go pricey with watercooling. You're trying to cool 1000w and that won't happen cheaply.

Thanks, this is really helpful.

Daddyjaxx said:

First thing, 4k for this project is not nearly enough. You're talking 1800 in GPU's alone and another 400 for the motherboard. A case to hold this kind of gear would be 300.00 or more. That's 2500 without a CPU, memory, PSU(s) (you'd probably need a couple), drives and we haven't even talked watercooling yet that would run 1500 or more, etc.

Click to expand...

Yeah, I come to realize that the budget will have to creep up somewhat. I was considering trying to get away with one monster PSU (seen some 1.5kW models) and therefore a cheaper case. Other than that, your estimate seems spot on.

You are pretty limited to full coverage waterblocks for 295's due to the dual GPU's. You do realize you could SLI two of the four and the other two are just independant cards...right?

Click to expand...

As this will primarily be a folding rig, SLI doesn't matter too much. Whenever I decide to play a game or two, I will be quite happy with what just the two of the four 295GTX's can do for me

Connecting them all together is easy for a block like this:

http://www.performance-pcs.com/cata...=product_info&cPath=240_582&products_id=25949

When you remove the stock cooler you replace he double slot PCI with a single. You use a normal barb on the top of the first card and bottom of the last and connect the rest with something like this:

http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=342&products_id=24980

Click to expand...

So basically all four cards will be hard-connected to each other by these little tubes? That's an interesting idea, but I'm concerned about the exact dimensions - what if the connector ends up being 0.2" too long and won't fit between the cards?

You need at least two good 3x120 rads or more, one for each two GPU's and if you want to cool the CPU, that would be another plus the block. About the only case that can handle all of this (Special motherboard, rads, two PSU's) is a Mountain Mods and you're talking 550.

Click to expand...

I was actually considering using one monster rad for everything, and just let it (and the pump) sit separately from the case. This would let the case be smaller (and cheaper). Wouldn't that also be quieter and more cooling-efficient?

P.S. Just for the record, I found a waterblock with tubes sticking out parallel to the card itself, which means no problem installing 4 in a row:

http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=576&products_id=26140

Your speaking of a rig with 4x GTX295 and OFTEN using the word "CHEAP" ........ there is something WRONG here.

One rad won't come even close to cooling 4 295 GTX's. You are talking eight 275 GTX's here.

Those connectors work perfectly. You connect one, pull it to the next card and connect it to that one.

The perfect setup would be three individual loops IMO. One for each two cards and one for the CPU. Folding on 4 of these cards will generate a lot of heat.

You'll need to get rid of some major heat man, I don't think a single rad designed for PC water cooling can cut it. I've seen one though designed for 9x 120MM fans, something like that might do it, I'd go with two pumps too if you'd like to do one loop. I think three 2x120 heatercores / radiators (or one of those large 9x120s or a car radiator or something) and a pair of good pumps would work, I would definitely put the cooling gear in an external box if that works out for you though, should make choosing a case a lot easier. You can definitely save some money on cooling and still have a good setup if you want to.

Boulard83, well "cheap" is a relative term. Nothing is "cheap" in this rig; however, I also don't want the components to be unnecessarily expensive. If the price is justified - fine, I'll shell out an extra buck; but if there's a more cost-efficient solution - why not consider it?

Ben333, that's what I was thinking - something serious, like a car radiator, and one or two high-power pumps. Might end up being a better solution. Three loops/rads are fine too (although more complicated), but I'm a bit concerned that if I stuff all this into a case (even if it's a large case), I will end up running a ton of noisy fans on all sides of the case, which kinda defeats the purpose.

Ben333 said:

I think three 2x120 heatercores / radiators (or one of those large 9x120s or a car radiator or something) and a pair of good pumps would work.

Click to expand...

We even sure that car radiator could handle that much heat? lol

If you run the water over all four cards, the fourth card is going to be running pretty warm... i really think that 2 loops would be best... you are cooling 8 GPUs here... i'm not sure of the TDP of them, but it's probably a lot...

On a side note - if you guys have better ideas of a setup for this kind of rig, I would be happy to hear them. So far, the requirements are as follows:

1) One system only (no farms);
2) Maximum possible performance for folding;
3) Usable as a desktop/gaming rig (I rarely have much time to play, but want to have that option);
4) As quiet as possible (it will be located either in my bedroom or in the closet right next to it, so something that sounds like an Airbus won't work);
5) Preferably, the main unit (case) not too large (although this is up for change if it turns out external rads are not an option for some reason).

Initial budget was $4K with air cooling; now that I am considering WC, this will probably have to be $5K or so. However, I don't want any ridiculously pricey solutions like Tesla (which in fact doesn't even perform much better than a gaming GPU).

Let me know what you think. I do realize I might be speaking total nonsense - I was out of the o/c world for about 3 years now, so I'm obviously out of sync. Any comments appreciated.

sounds like you need to build a custom rad/pump/res case like i did.

here is the build.


it keeps the main case clean and silent (if you have the external farther away then i do and closed off more)

i would do 1 big loop and get the XSPC dual or even triple top with 3x mcp355's.

Let me chime in for a sec. To watercool FOUR GTX 295's you have to go full cover blocks to make them fit side by side. Thats ohh $150 each. You can use one rad, as long as it's a MONSTA Feser and the required fans. All you need is a DDC3.2 and a good XSPC restop. While folding you'll probably be at 200 watts or so on each GPU, so 800 watts at a 15C delta should be fine.

That should be enough cooling for the GPU's. At about $1000 (+100 maybe) total to cool the GPU's.

Then a decent CPU loop of the same pump, good 120x3 rad/fans and pump. Hose clamps etc of course for both loops. The CPU loop can easily be done under $300 or so.

The OP needs to uderstand this rig while folding will make a TON of heat. The room this is in will need supplimantary cooling, like an AC unit in the window.

My sig rig, with the house AC set at 80F, thermostat in another part of the house. My PC room was at 80F. I primed my chip and GPU at the same time to stress test (no overclocks and just ONE GPU at the time), my room was 89F an hour later. Standard secondary bedroom size.

No matter watercooling or air cooling, you WILL need extra room cooling to make it livable. You also need to undersatnd that watercooling is still connected to the ambient air temps. You got poor ambients? You got poor temps.

Your best bet is a Big portable AC unit in a small room, with cables running out of the room so you have some hearing left. Save your money, don't go watercooling, because you need to spend it on the AC unit and your cooling electricity bill with that massive folding rig running 24/7.

CompuTamer said:

If you run the water over all four cards, the fourth card is going to be running pretty warm... i really think that 2 loops would be best... you are cooling 8 GPUs here... i'm not sure of the TDP of them, but it's probably a lot...

Click to expand...

In a closed loop there is only a diference of 1C or less between one spot and another, the 4th card should be as cool as the others. I personally would run one giant loop with something like a car radiator or one of those 9x120s to cool all four cards and the CPU, I'd use a pair of MCP 600 / 655s too, maybe an Eheim would work better for a large loop too. If things don't work out with that setup, you can always buy another radiator and pump to either work into the big loop or put the CPU on its own loop.

@ Conumdrum, I know the cards' GPUs are rated at those wattages, but in the end I don't think thats the real amount of heat coming out of them. Whether they are watercooled or not, that heat will still be going into the room so I'd say its worth it. If it ends up heating the room up a noticeable amount which I agree it will then the RZA might have to look into a window AC or some other solution. Depending on the climate, maybe having the large radiator outside, or build a box to keep it in the window.

Conumdrum said:

The OP needs to uderstand this rig while folding will make a TON of heat. The room this is in will need supplimantary cooling, like an AC unit in the window.
.

Click to expand...

What about having the exaust air going outside?

I say for sure go water , Get 2 big truck rads Put them outside No noise except for the fan in your PSU + your HHDs

honestly if you are going with the blocks you posted earlier, I'd look into having it on 1 big loop but instead of running the cards in series run them in parallel just split before the cards and join back after... but that's just another idea in your melting pot

Looking foward to pics of this project. I would like to get back into folding but can't afford the extra ££ it puts on my electric bill

OMG that's something I didn't think of Extra $150/month right there... Ouch.

Still, I want to try to build this baby.

Spawn, I would probably try to stuff everything except the rad into the case, so that the exterior is as neat as possible when the case is closed. Don't want wiring/tubing/etc all over the place. (At least not in my bedroom If I had a basement, I would totally go your route.)

Conumdrum, question for you: why do I need a separate loop for my CPU? Given the amount of heat those 8 GPUs generate, adding CPU into that loop should be a joke, no?

As to the climate - it is actually freaking COLD here all year round, as for my tastes. My room runs at 65F days and 55F nights most of the year. So I actually have a heater in my room - could use some extra heat from this baby

Ben333, I think you're spot on - regardless of the cooling system, all the heat ends up in my room. WC is much much quieter, so I'd rather pay $1000 for being able to sleep from time to time

deed, this might actually be an awesome idea. I have a window in my closet - I can put the rad right next to it and have the fans blow outside.

Console, well putting stuff outside is quite complicated (I rent a room, so have limited permissions), and also might get me in trouble if this thing gets a lot of sunshine. The last thing I want is for it to heat up to 150F and fry my PC.

Flurp, the idea is interesting, but in Swarm's thread people suggest it doesn't typically work out well, unless perfectly executed. This will be my first WC, so perfect execution is unlikely to happen


Question: does the tubing length matter substantially? I assume it does as it adds flow resistance, but to what extent? Will I be able to have the case in my room and the rad in my closet? It's like 10' apart.

Just noticed you msg to deed, Would it not be better having the fans sucking air in from the outside instead of blowing warm air out??

As far as I'm aware tubing lengths don't impact on cooling a great deal. Ofcoase you will need good pumps for that setup.

I think an argument can be made for both ways. I can try both As long as tubing allows me to place it that far from the PC itself.

i would grab a pair of mcp655's for silence and performance. as you saw in my thread i have a good deal of tubing (almost 20 feet) so you should be fine with all the stuff you want plus 10 feet of tubing to the closet. though if you plan to keep the door closed that won't work to well.