Single line or multiple loops for CPU + GPU?

Hi, I'm looking for opinions about whether to use a single line feeding both CPU and GPU blocks, or to put a "Y" in the line and run them each from a seperate loop. Right now, I have a Thermaltake P500 pump pushing water through a 7" x 7" heater core, then it splits and runs one line to my CPU followed by the Northbridge, and a second line runs to my GPU then rejoins the first before entering the resevoir and returning to the pump. Waterblocks are my own mill work on the CPU and Northbridge, and a Danger Den 9800GTX/GTX+ full coverage block on the GPU. Tubing is 3/8" ID, coolant is plain distilled water. BFG Tech 680i SLI w/Core 2 duo E6600 @ 3.320Ghz/1.46v, XFX Geforce 9800GTX 512Mb @ 810Mhz/1910Mhz/1140Mhz & SPP is 1.45v. CPU and GPU temps are hovering around 43/44 degrees C under browsing/surfing load.

Thanks...look forward to hearing your thoughts on this.

I learned from bitter experience that the Thermaltake 500 pump is a) not reliable enough and b) not powerful enough to have multiple loops.
If you use a "Y" both water blocks have to have the same resistance to flow or one of them will not get enough volume of water to cool effectively, so I would say go with a single loop.

Load up the CPU with Orthos for 1 hr and give us load temps. Then do the same with the GPU using Furmark at your max resolution. Then we'll know what to recommend.

Splitting loops is considered a big nono with most WC sites. Most modern blocks need xxx GPM to be effective, splitting loops reduces flow terribly.

If all you have is one pump, then stick with one loop. No point using the "Y".

PS. I recommend you upgrade the pump to something more powerful, reliable and not Thermaltake. Don't do Thermaltake for watercooling.

rouge34rtw said:

Waterblocks are my own mill work on the CPU and Northbridge,

Click to expand...

Pictures? (Of the insides). Please.