Subject: Side Fans and Ducts
By: JDNightWalker (IP: 139.182.47.*)
Written on: 10-01-2006 22:46

Hello! I'm hoping I might get some opinions on an overheating problem and possible solutions.

Before I start, the pertinent facts:

HP Media Center m1050y Micro ATX Case
Intel Pentium D 830 3.0GHz Processor
Intel D945GTPLKR Motherboard
1.0GB DDR2 667MHz RAM
ATI Radeon x700 PCI Express Video Card
Creative SoundBlaster Audigy2 ZS Sound Card
Conexant TV Tuner
Antec TruePower TPII-550EPS12V 550 Watt dual-fan Power Supply
Dell 1905FP Flat Panel Display connected via DVI


Over the Christmas Vacation, I rebuilt an HP Media Center m1050y computer, upgrading it from a Pentium 4 to a Pentium D 830 3.0GHz processor. The case is a crowded Micro ATX case, and the motherboard I used was an Intel D945GTP mATX board. At first, using the boxed Intel heatsink/fan assembly, the CPU was running 55-60C idle and up to 70C under load (according to Intel's Hardware Monitoring Software, not the BIOS.) I upgraded the heatsink assembly to Thermaltake's Big Typhoon and used Arctic Silver 5 for the thermal grease. Idle is now about 45C, 60C under heavy, constant load.

The problem I have now is that the Graphics Processing Unit (GPU) is overheating, I believe, due to the sheer amount of heat being poured into the case from the CPU. The symptoms: When I use CPUBurnIn to put the GPU and CPU at full load, or I do a lot of running around in the graphics-intensive game Final Fantasy XI (1280x1024, other graphics setting also set to their max) I can hear the GPU fan kick into high gear, and then after a few minutes the monitor starts to lose signal and go into sleep mode. Under an older driver version, the monitor flickers in and out of sleep mode. Under the latest drivers, it goes to sleep and never recovers. Both require reboot, and sometimes the symptoms continue even after a "warm boot".

Solution 1

My first solution was to replace the secondary rear 92mm fan with a more powerful TurboFan from Mad Dog Multimedia as well as fill the last available card slot at the very bottom of the case with another slot-type fan. The slot fan has a max CFM of 35 and the 92mm fan's max CFM is 55. Both fans should be running at their max, as they are both connected directly to power, not through the motherboard (where the CPU has regularly been slowing them to quiet the computer.) So far, with all this air being exhausted from the case, I have not yet been able to recreate the glitch, the GPU fan will kick to high for periods of a minute or two here and there, but that's it. The CPU is also running a few degrees cooler.

The problem is that my nice, quiet computer now is a few decibels away from a jet engine or a loud server.

Proposed Solution 2

The front of the case is too small for me to mount anything but a couple 60mm fans, so it doesn't allow me to do much in terms of actively drawing air in from the front. The way that the HP case is designed, the side farthest away from the motherboard, the opening side, isn't a sealed side. It's covered in pinholes to allow some air to be drawn in that way. What I'm thinking about is possibly slicing into that side and mounting a 120mm fan directly over the four card slots, drawing cool, bottom air in over the cards that would then rise and be exhausted out and up via the rear aux fan and the two PSU fans. To try and give the CPU less recycled air and more fresh, outside air, I was also thinking of making another 120mm slice over the Big Typhoon's 120mm fan and possibly making a short duct out of something like duct tape (not dissimilar to the duct shown in articles on this site.) I've seen a duct like this before in some of Antec's Thermally Advantaged case designs. I can then return the rear aux fan to the CPU's control (so it will be quieter) and remove the noisy slot fan.

Please tell me what you think of this new solution? Is it viable? Is it worth it? Do you have any other ideas I haven't thought of? All comments welcome!

Thanks in Advance!!

By: JDNightWalker (IP: 139.182.47.*)
Written on: 12-01-2006 17:43

I just wanted to post an update for any interested parties.

I went ahead with my proposed solution 2 and have been met with success. I made a square slice for the 120mm fan of the Big Typhoon CPU cooler, used a chrome wire guard to protect the opening and constructed a short shroud just inside the case out of a clear plastic box that used to house some other computer part when it was on the retailer's shelf (I put a spare 120mm fan inside it just for comparison, it fit perfectly. New life given to a box that would have otherwise gone in the trash.) I also made another slice over the PCI and PCI Express slots and mounted a 92mm fan and wire guard (couldn't fit a 120mm fan there, not enough room.) Here are the results:

CPU Temperature (idle): 42-45C
CPU Temperature (load): 52-53C
Unable to keep GPU fan at high for long periods (except during a pure graphics burn-in test)
So far, unable to recreate prior reported graphics glitches.
Computer fans are quieter than the on-board GPU fan at full load (my benchmark)

The only really strange but understandable thing I now experience is the fact that, now that so much air is being pulled in by the CPU and side fans, there is air coming out from every opening. Front, back, even a few air holes added on the opposite (motherboard) side of the case. The air coming out feels fairly cool to the touch, so for now I'm seeing it as a good thing, that all components are getting nice, fresh air, even if it's coming from the opposite direction it used to.
By: roller377 (IP: 64.12.116.*)
Written on: 05-03-2006 20:27

hey bud i run a 3.40eghx prescott at first i hav an old case i moded to hold two 80mm fron intake fans & a big typhoon cpu cooler i swaped the orig 54cfm fan with a thermaltake A2018 94cfm FAN and the only exhast i had was the power supply it had a bottom fan & a fan at the rear of the case, i got it to idel at 27c-30c and with prime95 benchmark i never went over 39c this was good for an old white case i moded a little, but as i got the case i was waiting to afford the lian li pc-65b with dual 80mm front intake & 1 80mm on top,1-80mm rear -the idle temp stayed the same & max temp was around 35-37c so i made a realy thin alum duct for the power supply fan to blow away from my rear case fan & turned it around then used a very thin duct to direct the cool air to the typhoon it made my idle temp 27c-& max around 33c no joke & room temps around 75 F if you need more help email me at dunccolwe at as i can give more detail from my trial an error
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