Radeon 5970 + Zalman WCing

One, the load ability of the Zalman is wayyy below your required heatload dissipation. You need to remove 600 watts of heat with two cards, the Zalman might be able to remove 150 watts with no fans.

I see lockups and frustration in your future.

Two cards?

And how can I tell (a) how much heat I need to remove, and (b) how much heat a certain waterblock removes?

You said you need two of them. Rereading I don't know what you mean, two of them.

You start at the top of this forum and read the watercooling? Read first post. Many links inside and helpful info.

Something to help figure out your wattage requirements.
http://www.overclockers.com/forums/showthread.php?t=635...

Well, if you looked at the images I linked you would see that the 5970 has two GPUs - ergo two VGA waterblocks required.  

But I spent all my lunch hour browsing watercooling guides both here and elsewhere, so I'm a lot more confidant about putting my own system together now. I see your point about how a passive radiator may not be able to remove enough heat for both a 5970 and a CPU.

However I do still have one question - would it be better to go for a full cover waterblock for the 5970, or two GPU blocks?

I am using a powercolor 5970, it comes with a waterblock.
I think it is better to use a custom waterblock since it covers RAM and VRMs.

The problem with GPU chip only cooling, like the MCW60 made by swiftech is one thing for older cards, but TWO now for the 5970.

First, the mounting and hose routing. I can say it will be an absolute pain unless you have done it before, have a box full of of different fittings and just been around the block. I don't even know if the MCW 60 even has a buyable adaptor plate yet for that card. Go to Swiftech and see what they offer. Good company. Gabe the CEO is a smart guy, I know him somewhat.

Secondly, going GPU only WC, the VRM chips on the 5970 need REALLY good cooling. You'll need to really find the tallest, bestest heatsinks and using the best Thermal Tape(TTape) AND great fannage on them to keep them cool.

The card is a beast. If I was to get one, I would ONLY go full coverage block. $150?? I would also put it, by itself on a 120x3 radiator, seperate pump etc. By god it puts out almost 300 watts of heat.

You go big boy toys, you have to put out big boy $$. Or put up with the fan noise. I sure hope you got a real modern case with TWO 120x2 fans as intake and TWO outake fans. Might need to get better case fans.

My rig:
http://www.overclockers.com/annual-water-cooling-cleani...

Thanks for your help Conundrum, I'm a lot more confidant about how best to watercool now - through reading stickies and other posts etc.

Anyway, the rest of my system is a 930 i7 on a Gigabyte GA-X58A-UD7 motherboard. I have now planned on a Swiftech/Laing MCP355 pump and MCRES micro res, along with a 120x3 EK Coolstream XT 360 (the case is going to be a Coolermaster Cosmos S). A Swiftech Apogee XT and an EK-FC5970 would complete the circuit.

However, I see that even this may not be enough to keep all the components cool, given how much heat both overclocked i7s and 5970s generate. Two circuits may be necessary, in which case my case may not be big enough. I might just watercool the i7 at first, and leave the 5970 on stock air cooling to start with.

I am using a similar setup. i7 920, gigabyte UD7, and 5970 w/ ek waterblock

I am using a dual thickness 3x120 radiator on all CPU, motherboard, and graphics card. The card loads around 40c after some OC. Processor is around 40c as well.

It really depends on how much you OC. I have my i7 at 3.8ghz and the 5970 at 950mhz/1200mhz. I could go higher but a opted out for lower voltage and lower heat. Even with better cooling I will pass on the extra heat being dumped in my room. Dissipating the heat isn't a problem.

+1 Rofl_My_Waffle

If you OC to comfortable levels (3.6-3.8Ghz seems to be the sweet spot between low voltage and speed), you will not only skip out on the ridiculous amounts of heat that i7s can put out, but still have a CPU that is quite a step above what the default clocks are.

You had a great answer. Balance is really important, many miss that. Life will be good for you unless your old like me and took many years to learn about balance. I'm toast.

Geat answer!

I once was an apprentice baiter on a fishing ship, looks like you became a pro! JK!!!