Opinion on this W/C loop

I'm building a case from scratch and this is the cooling loop that I came up with. Note that the side with the pair of 5870's is the max heat load that I'd likely put on that side. I left out the pumps and reservoirs to simplify the illustration. Yes, it's a dual system case. Basically I want to use something like a Koolance plate heat exchanger to dump the heat from the P4 system (server) to the main loop right before it hits the radiator.

If this isn't practical, I'll just use a motherboard tray with a 120mm fan port and use a single 120 radiator. I figure the temps wouldn't be too bad if I have to use my backup plan because I'm using a 2x 120 radiator with a single fan (damaged the first fan, too lazy to replace) and temps aren't too bad.

*OR*

Would it be more practical to just add the P4 to the loop?

http://i86.photobucket.com/albums/k9...g?t=1285159402

That looks generally good; you'll want to put the res and pump (in that order) between the rad and CPU. OOC, would it be possible to just do a straight tubing run over to the P4? I ask because with it like this you would need another pump (and maybe res if you feel so inclined) for the P4. You also might want to consider trying for more rad space. My general rule of thumb is at least 1x120mm of rad space per major heat producing component in the loop, so you'll definitely be safe but I'm not sure if you'll get really good temps or not.

I would add the P4 into the main loop or branch it off the main loop with a pair of Y-connectors. In order for the heat to exchange from one loop to the other, there has to be a heat difference. The greater the difference, the quicker and more efficient the exchange. I don't see the P4 ever getting hot enough by itself (safely) to force heat into the larger loop. I think the water in the P4 loop will be much hotter than it should ever be, and the chip itself will be even more so.

Put both CPUs before the GPUs and there should be no issues at all. Just make sure that the pump and rad fans come on whenever the server is on (assuming it's always turned on) instead of when the gaming rig is on. I'd also suggest a second fan with the P4 added to the loop.

Thanks for the input. It's a rough idea right now. When the build progresses a little further I'm sure the w/c loop will as well. I might just end up using a single 120 rad for the P4