Need some advice on a dual loop cooling system

Hi guys,

I'm helping a friend design a water cooling solution for his PC..

i'm trying to design something that would be pretty effective but i'm not sure what would be more practical or better idea etc..

basically it's 1 quad core loop
and 2 4870X2's running in crossfire...

cooling system should be able to handle all 8 cores @ 100% load... (not Overclocked)

the main reason for this setup, is because it's running Unix/Linux and the drivers are non existant and the fans run 100% on both cards 24/7 so we want a quiet cool machine

i'm drawn up something I was thinking of doing..

i'm not sure if I should completly split them or share 1 radiator and 1 resevoir..
hence why i'm looking for advice..

Should I have 2 seperate feeds from the Resevoir to each pump? (seems logical)

would it be better to have 2 smaller rads instead of 1 beast? and make 2 completely seperate loops?

if the whole thing doesn't fit in teh case (it's a full tower tho) it's not the end of the world..

model numbers refer to danger den products




let me know what you guys think

TIA

Running the loop in parallel is a bad idea. Get another rad and just make 2 loops.

I agree with atomic. Split it up into two loops. Run one of the on the cpu solo. Run the other loop with the two gpus in series. Running the video cards like this makes sure you always have good flow through both cards. You don't run the risk of one of the gpu blocks having more restriction and messing up the flow to that card (water will always go the path of least resistance).

Another +1 to separate loops. If you use the Primochill Typhoon III reservoir (they're insanely good for it), you could get away with one res and one pump (D5...get the vario and put it at top speed), but I'd suggest two rads. With the money saved on one of the pumps, you could get a decent rad for the CPU.

Two suggestions - since he's quieting it down, I'd not go with a HWLabs GTX rad; their high fin density doesn't equate to effective quiet cooling. Second, unless you're trying to use a block he already has, there are better blocks out there. HeatKiller 3.0 LT (or even the LC if you're going for a budget block) are good options, as is the Swiftech Apogee GTZ, which is down to only $50. The Swiftech Apogee XT is great, but doesn't come stock with an LGA775 backplate.

Thanks guys.. keep it coming...

no parts have been purchased yet, I didn't wanna pull the trigger till I did my homework first..

khemikal said:

Run the other loop with the two gpus in series. Running the video cards like this makes sure you always have good flow through both cards. You don't run the risk of one of the gpu blocks having more restriction and messing up the flow to that card (water will always go the path of least resistance).

Click to expand...

U said series.. But I assume you mean parallel?

if it was in series.. the 2nd card is gonna get bathed in hot water exiting the first block no?

Nope, he means series. It's easier to run in series, plus the water temperature increase between the cards is going to be minimal. Yes, it will be ever so slightly warmer, but the water is moving so fast, it won't increase that much.

Most of the time parallel is recommended against b/c block restrictions will fight against each other (higher restriction blocks will get less of the water flow than lower restriction blocks). In your case, if you wanted to run them parallel, it would be ok b/c they're identical blocks. Like he mentioned though, if something impedes the flow of one of the blocks, that block will be starving for water while the other one gets all the flow.

No, he means series. The change in water temperature is small and doesn't significantly affect performance in this case. Running anything in parallel forces the water to take the path of least resistance, and if both routes aren't exactly equal, one card will get less flow, which will affect temps more than running them in series.

edit: you beat me to it.

Ottoman said:

U said series.. But I assume you mean parallel?

if it was in series.. the 2nd card is gonna get bathed in hot water exiting the first block no?

Click to expand...

your likely thinking that when the water goes in the block, say at 20C, it will jump to 40C or so when in fact it will leave the block more like 20.5 or 21C.

the change is so small it won't effect the second gpu much if at all.

Sorry to resurrect this thread from the dead
life got busy for awhile but back in order now..

I'd like to order the parts asap.

so what parts would you recommend?

blocks: HeatKiller 3.0 LT
vidcard blocksanger Den x2 blocks
Pump: 2x DD's D5's

so I need 2 res's, fans, and 2 rad's to cool all that heat without making a racket..

the less places I have to order from the better..

how are Dangerden's rads and res's?

I would suggest the following:

CPU: HK or Apogee XT
GPU: Whatever Fullcover you can find
Pumps:2 x DDC/mcp-350/mcp-355
Res: XSPC Dual DDC 5.25 bay res
Fans: Yate Loons
Rads: 2 x MCR320