I currently have a Core i7 920 @ 4Ghz and a HD5850 @ 1000/4800 under water and in one loop, The loop goes like so:
This works great, after a few hours having fun on BFBC2 my CPU is at 50C and my GPU is at 40C, However the HD5850's VRM's are touching 80C and as I would like to add another HD5850 to the loop I want to first add some additional cooling power in the form of a XSPC 120mm Single Radiator, mounted internally in my case.
The new loop would be like this:
Res>Pump>Triple Rad>CPU>Single Rad>GPU>Res
My question is, will my pump be able to effectively pump the water around the loop?, At the moment it does a great job, the water flows pretty fast around the loop.
Laing DDC-1T Pro Pump 440 L/hr 10W (MCP350) : DDC-1T
XSPC Laing DDC 200ml Reservoir Pump Top : Plexi
XSPC 360mm Triple Radiator Black - RS Series : RS360
Watercool Heatkiller LT Rev 3 CPU Waterblock for Intel 1366 : Acetal
EK Full Cover Waterblock for ATI 5850 Graphics Card : FC5850 Plexi
XSPC 1/2" ID - 3/4" OD (13-19mm) High Flex Tubing : White 2 Meters
6 x Barbs and Hose Clamps
Bi distilled water + Petra's Tech PT PHN Nuke Concentrated Biocide
To begin with, I would not recommend running from pump into the rad, as it kills your pressure right off the bat (CPU blocks need as much pressure to them as possible to cool adequately, as they have such a small area they need to remove heat from). I'd have the rad as the last piece in the loop before making it back into the res.
I think that your best bet is two separate loops, one going Res-pump-CPU-rad-res and the other res-pump-GPU-GPU-rad-res. I know for sure if having 4x120 total would be enough rad for a loop with an i7 at 4GHz (at least 190w of heat to dissipate) and two 5850's (about 150w stock/ at least 175w at your clocks, each).
You won't need another res (if yours has two in/outputs, if not, a Dremel is your friend!), but you'll need another pump, rad, and GPU block.
Let me put it this way, I've got a fountain pump for my setup that has roughly twice the GPM that yours does, and I have it passing through my CPU, then GPU full cover block, then through a 10"x12" A/C evaporator coil (cools about as much as a 2x120 rad, I've got a true 4x120 rad on the way), and the pressure is maybe 1/4 what it was to begin with. The true rad will relieve that some, though.
I think that adding another block for it to push through, and then ANOTHER rad, will be too much for that single pump alone.
I'm sure it will work aleast till he can buy one more pump. The flow may not be what most would want but it is a strong little pump. He could possible mod it to a 355 if his pump has the open pin/jumper. I would need pics to let you know. I'm not sure what you have without the name of your pump (fountain pump?). I have 4 MCP655 in my rig and have MCP355's in most of my other rigs. I have ran a MCP355 in a system with 2x triple rads, 3x EK blocked 4890's, Chipset block and a EK cpu block and had no flow issues. I would say he is not running as much as i am and his pump is a little lower wattage but i think he will be fine! If needed i will run a flow test for him... If you can mod the pump to a 355 it would be great. Also GPM is not what always counts head pressure has alot to do with it also if not more! If he don't use to much extra hose and not to many 90's it should be fine. Not perfect but it will work. Maybe look into a cheap pump top to help with the head pressure.
I'm just gonna go for it and see how it does. I think it'll be ok. I'm optimistic
Worse case it will work till you can get another pump!!! just keep the hose as short as you can and try not to have to many 90's none if possible. PM/post your results. I can run a test on one of my 350's tonight i you would like first?