Fan placement in system with fanless PSU

Filias Cupio · Post by **Filias Cupio** » Thu Mar 09, 2006 5:34 pm

I'm looking to move to a passive heatsink in the near future (Ninja, unless the Thermalright HR-01 becomes available in NZ Real Soon Now, and at similar price.) I'm wondering about the best placement for case fans.

I have an Acousticase C6607 case, which is a standard tower case layout with two 120mm fan ports: one just under the powersupply, the other bottom front. I also have a fanless Silverstone PSU. I have an Athlon 64 3000+ CPU, and a single Samsung P120 HD (SP2004C SATA.) GPU (AGP Radeon 9200) and Northbridge have Zalman fanless heatsinks. There is a removable course foam airfilter over the front port.

The current layout is the CPU has stock heatsink and undervolted fan, a single 120mm fan sucking on the front fan port, and the rear fan port blocked. This forces the exhaust air through the PSU, which should help cool it. The front fan also blows directly over the HD. (The front fan is a Thermaltake SmartFan 2, which was very disapointing noise-wise. It is undervolted to the point where it has just enough to actually start. I have a Nexus 120mm on order which should give more air and less noise.)

Here are some layouts that could make sense:
Front sucks, rear blocked (i.e. the current layout.) This makes it a single-fan system, for bonus Macho points, and exhausts through the PSU - but will it provide enough cooling to the CPU? Flow through the PSU will also have just come off the CPU HS.
Front suck, rear blocked, fan on CPU HS: as above, but better CPU cooling
Front sucks, rear blows: better for cooling CPU, but might not get much flow through PSU.
Front and rear suck: Lots of flow through PSU (only exhaust route), although the PSU input air will be straight off the CPU.
Front open but fanless, rear blows: good exit strategy for CPU heat, but likely not much flow around HD. Some of the air that enters through PSU will have already been through once and heated.

On top of all this is the question of whether I should remove the air filter on the front fan port.

Any thoughts? I'm inclined to try sticking with the current layout, for the sake of the single-fan-macho-points bonus.

Chris Chan · Post by **Chris Chan** » Fri Mar 10, 2006 5:24 am

I'd say to leave the front open but unfiltered, and the rear with a fan. Same setup as I have, and it'll give great cooling to the CPU HS.