How powerful a pump do i need for this setup
 

my system is a 4400+ OC 2600mhz
2 256mb 7800gtx

i plan to make the case look neat and clean
but the 3/8 tubing looks nicer than 1/2

the blocks i will be using is the storm or the apogee
2 maze 4 gpu water blocks
and a DD xtreme 2 radiator with 2 120mm fans


do you think the 3/8 tubing with a swifftech mcp350 pump will give about the same performance as 1/2 tubing with a swiftech mcp655 pump

and if the 1/2 tubing is better then by how many degrees

Re: How powerful a pump do i need for this setup
 

Wont be much diff between the 2 really. Dont go with the BIX though, you need loud ass fans to make it perform, get the BIP or a PA series Thermochill.

Re: How powerful a pump do i need for this setup
 

Approximator to the rescue (really must post this version online).
Note I have done some substitutions as I don't have PQ/CW data for your bits.

MCP350
Storm on 110W CPU (big fat guess at wattage)
2 x MCW55 each on 50W GPUs
MCR220QP with fans at 7v (this rad is probably less flow restrictive and air restrictive than yours, but I'm yet to add in figures for the DD Extreme)
Assume 2m of tubing to hook it all up.

Now, my model does not handle changing barb sizes. So, it assumes you are stretching 3/8" tubing over the storm's 1/2" barbs, and the HE120.2 model assumes 5/8" barbs. This is the coding I am doing now, but meanwhile...

3/8" tubing: 2.64 LPM, coolant at 10.27°Caa (degrees C above ambient), CPU at 26.64°Caa, GPU 1 at 10.87°Caa , GPU 2 at 11.14°Caa

1/2" tubing: 2.76 LPM, coolant at 10.26°Caa (degrees C above ambient), CPU at 26.54°Caa, GPU 1 at 10.83°Caa , GPU 2 at 11.09°Caa

W00t! Now the Apogee is a better choice IMHO for this loop. It may perform worse on the CPU or not (fight rages in other threads) but it is less restrictive for the flow rate, and 2.x LPM is not ideal.

That said, fitting a MCP655 will only know one degree tops off your CPU temp, and that's with 1/2" tubing. The best way to lower temps here is that the water temp is a bit high: suggest PA120.3 rad if my wattages are right.

Re: How powerful a pump do i need for this setup
 

In a nut shell ...

Storm, use the D5 (mcp650) with 1/2" ID tubing.
Pros: D5 has speed control
Cons: D5 is large

Apogee, use the DDC-1 (mcp350) with 3/8" ID tubing.
Pros: DDC-1 is compact and powerful.
Cons: No speed control, must add separately.

For an error of 1 or 2 degrees, more or less, the 3/8" tubing works the best inside a case.

Personally, I have an external WC'ing setup. Only two tubes run in/out of the computer. Less chances for leaks to occur.

Re: How powerful a pump do i need for this setup
 

Just get an MCP655...lol