Experimenting with Case cooling

Did some experiments with cooling my case over the past few days and thought I would share the info. I was a bit surprised and let down by the results to be honest.

Here is my system, please don't laugh its an upgrade as I go kind of deal lol.

Windows 7 64 bit
Biostar mcp6pb m2+ mobo
AMD athlon II x2 240 2.8 ( overclocked to 3.5)
4 gigs of PNY ram (2x2 gigs)
PNY 9800GTX+ with 512 of ddr3
140 gig sata HDD (7200 rpm)
DVD drive
Black Widow power supply

All this tucked away in a 2 year old Emachines case with the stock cpu heat sink and fan. Basically the Emachine has been gutted and upgraded. The only original parts are the hard drive, case and dvd drive.

I was running this set up tucked in a hole in my computer desk with no door in front of the tower. The hole is not quite twice the size of the tower.

Normally I run this with no cover on the side of the tower, I just leave it open to let air circulate and because I am always messing with it. I decided to see what would happen if I installed some fans and put the cover back on it. So off to Staples I went ( only place around me with any selection of case fans to speak of).

I came home with three antec fans. One 120 mm 3 speed fan, one 80 mm 3 speed fan and another 80 mm single speed fan. The 80 mm fans have a 30 cfm rating and the 120 has 80 cfm in high speed. I also had a spare 80mm cpu fan I robbed from my old motherboard. I don't know the cfm, but it cranks. Runs at 4500 rpms and moves some serious air compared to the new ones I purchased.

I did some torture tests with a video tester and prime 95 to get a base line of temps while at idle and under a full load. And ran the same tests with different configurations of the fans. I tried positive, neutral and negative set ups to see which would work best. Temp readings were taken with CPUID monitor.

I have one 80 mm fan in the back ( the fast one) and another in the front. I modified the front face place to mount it on the bottom of the tower. I put the 120 mm fan on the side near the top and the other 80 mm fan on the bottom blowing right on my graphics card. ( that sucker gets HOT under a load!).

Base line for the CPU was 31 at idle and 58 under a load. This is with the cover on it like it was stock. Only cooling was the stock heatsink and fan on the CPU

The 9800 gtx+ was around 52 at idle and 86 under a load. Yes I said 86 freakin degrees C! The card is slightly overclocked and the fan speed is set to stay at 100%. This obviously needed some attention. I took the heat sink off the graphics card and trimmed away some of the plastic cover that enclosed the whole heat sink. I felt it was trapping heat inside and not letting air to flow around the heat sink. I put the heat sink back on using Antec Thermal 5 thermal paste. The heat sink actually touches the GPU and chip sets on the card.

Next I ran a test with the cover off the side like I normally run it.

CPU was 23 at idle and 52 under a full load, and the graphics card went down to 41 at idle and 72 under a load.

After trying several fan configurations with neutral, positive and negative flows the best I came up with was a negative flow system having the back fan sucking air, the side 120 MM sucking air, the front fan sucking air and the bottom side 80 mm fan blowing in on my graphics card.

The temp for this set up are as follows:

Cpu at idle varies between 19 and 23 degrees, however under a full load it climbs to 56 C. Not bad for an overclocked cpu with the stock HS and fan.

The graphics card was better though at 40 C at idle and 65 C under a full load. That is waaay better than 85-86 C!

The let down of the whole thing is that the system ran more cool stock with the cover off! I could have easily added one fan to the graphics card to cool it down some. So I spent 50 bucks on fans, HOURS modifying my case and testing different configurations. The system is much louder and glows like someone spilled nuclear waste on it because two of the fans have LED's ( didn't have a choice in the matter). And I am sure it sucks more energy with all those fan running. All to get temps not quite as good as it was stock with no lid on it lol.


My next project will be modding an air purifier with two vent ducts blowing right into the computer.

Paul