Opteron & X850 on water
 

My main system has seen some changes, so here's the new description. The focus remains on near-silence with good performance. You can see more details at SPCR.

The PC has an Opteron 144 @ 2.4 and an X850 XT @ 580/580, while the loop uses a Cathar G4, Maze4 GPU, early DDC, and 2-333 heater core. Airflow comes from an 80mm L1A running on the Seasonic PSU's stock controller and a Yate Loon 120 on Sunbeam Rheobus. Both fans receive about 5V and run very quietly, though the low airflow limits cooling. The CPU's & GPU's reported temps stabilize around +30C over ambient when both are loaded.

I have a WD2500KS in a Smart Drive 2002 enclosure, which leaves the DDC as the system's loudest component. The Rheobus allows me to handle this by undervolting the DDC slightly, and that reduces the noise significantly. Since taking the pictures, I have surrounded the pump with foam as well.

Note the different hose sizes. Bacause I wanted to minimize downtime, I converted the pump's outlet and Storm's inlet to 3/8" to match the Maze4. The other lines are still the 7/16" I used originally, because the rad has 1/2" barbs. Likewise, the tee in the pump's feed line is a leftover from the system's P4 days and is in a poor location. I've found that two tee-lines allow very rapid filling/bleeding with the dual-pass radiator, but they do need to be high points. If I ever do a complete rebuild on this system, the plumbing will change a bit.

Here are the higher-res shots, with a sample below: Pic 1, Pic 2, Pic 3.

http://img.photobucket.com/albums/v4...CGPU3small.jpg

Re: Opteron & X850 on water
 

I'm still amazed that this works. Nice! Have you thought about attaching the DDC to a lead (or other) weight? Use drill and tap screws and attach it to a hunk of mass. I'm thinking of doing that to a DDC that I have since I don't move the computer around.

Re: Opteron & X850 on water
 

Not a bad thought, Brian, but I think the pump's acoustic output is more of a problem than vibration-induced noise. With the lined panels and such, this Genie is suitably massive! OTOH, a block of lead is dirt cheap, and another 5 pounds won't make the PC noticeably heavier... I may try that next time I open it.

Re: Opteron & X850 on water
 

This makes me wonder... How do you absorb high-frequency (16KHz?) noises well if they are merely being transmitted through the DDC case and the water+tubing?

Re: Opteron & X850 on water
 

For the pump, enclosing it in a high-density absorber (I've gone with foam in a heavy box) and for the tubing, I very much doubt 16kHz vibrations transmit into tygon.