Many have said that you can't have both power and silence. Well, after spending considerable time lurking in SPCR I decided to build something that would challenge that view.
-Maximum silence during idle while maintaining safe temperature
-Maximum performance without excessive noise.
-As little dust as possible, which means keeping the filter on the intakes. Many people don't use the filter in order to have enough airflow but this means opening the case monthly to clean it, especially bad since my room gets very dusty.
Xeon 3350 overclocked to 3.2GHz
tracend 4x2GB 1066
P5E flashed to Rampage formula
Cooler mater rs-850-emba
WD Velociraptor 300GB
Up to 8 fan active if neccessary
The build in a glance, Kama PWM on TRUE120 and S-FLEX 1600 on the back, you can also see the NB fan on the MB. The inside have Acustipack V2 triple layers on almost all surfaces. Standard 2 layers under the MB up to under the NB.
The acustipacks extend all the way to the very front end of the DVD drive. I found that this significantly reduced the noise of the drive.
Front fan cover after some cutting
Intake grille cut down to bare minimum need to hold the air filter, you can also see the 3 layer acustipack on the door and the heart of the cooling system.
The secret sauce of how to force enough air through the filter to satisfy a 4870X yet spinning slow enough. A triple fan sandwich of NMB-MAT 12G12L-BX and Saxon airflow straighteners. This triples the effective static pressure for a given rpm.
A hole was cut on the case allowing front panel cables to be routed through the space next to the floppy slot. The original hole is covered up by acustipacks.
Some people hate the top exhaust cover but I say its an opportunity. By weaving triple layers onto you can turn it into a muffler.
Unused space on front cover is filled with triple layers. This also helps blocking dust from entering through the gaps.
I could not cut the grill on the top without making it look ugly so I just left it, there is a temp sensor measuring the exhaust temp, there is another sensor taped to the intake to make a comparison.
The bottom chamber is filled with triple layers where possible and the tray itself uses double layers. There is a common opinion that the middle fan is useless, what they did not think about is why. The actual reason is that the gaps at the four corners of the separators have gaps that allow air to be recycled from the PSU chamber into the HD chamber. By using an wide I shaped piece of triple layer the fan can now properly work as intended which is pulling air into HD chamber from the front filter. In practice with the S-FLEX at 480 rpm it reduces the PSU chamber temp by at least 5 degrees. This also have the advantage of having the fan absorbed by the inside of the case instead of near the front which makesthe fan noise harder to block
sandwich (intake), back/top(exhaust), dominator fan (ram), bottom (taped to top of PSU)
The usual idle [gaming] fan speed:
sandwich-540 to 700 in summer [900 to 1000]
bottom-480 to 540
CPU-680 [speedfan controlled up to 1200 when CPU reach 60+]
Ram and NB - off unless I want to play with more overclocking
One other important factor is keeping idle heat low, this is by under clocking the 4870X2 to 275 GPU 0.9V and 300 Vram when idle. You can shave at least 10C of heat and about 10W at the wall. This allows the GPU fan to stay at 1200 rpm at all time in idle which is inaudible inside the case.
Total power at the wall using a some cheap power meter is ~184W. Peak power running burn-in's can reach 450W.
idle, The whole system is subjectively quieter that a tri-cool at low. the biggest subjective noise source is the coil whine from the samsung 245B and my ceiling light. The system only emits a faint whoosh.
Gaming, perceivable noise from the sandwich, but it is easily drowned out by the noise of the game especially using when headphones. And it's only as loud my brothers P182 with use tricools at med at all time.(he explicitly states that noise are not a issue for him
Sidebar on my 2nd monitor, at 19.5 intake temp: