What a difference a Rear fan Makes

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Snump

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I run distributed.net's RC5 client, so the CPU is at 100% constantly. I was running about 70 degrees C for a while. I dusted everything out, and nI ran at 66 degrees. I kept it like this for a while, and it woulf fluctuate between 66 and 68 degrees. I add a case fan to the back, and now its at 60. This is under an absolute full load. I didn't think just a case fan would be that big of a deal.
 

Wayniac

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It depends really. Sometimes if too much pressure gets built up, heat will raise like crazy. You need to have case fans to keep everything moving and keep the air circulating. Also, with no fans, your processor fan uses the same hot air over and over, but with case fans, it gets new cooler air.

Crazy how much of a difference it makes eh?
 

Elbatrop1

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I noticed a huge difference by just adding a couple of case fans. I went from about 35-36C idle down to like 28C idle.

I never thought it would make that much of a difference. I added them when I added my 9800Pro (from a 9200) to carry out the extra heat:)
 

Snump

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Wayniac said:
It depends really. Sometimes if too much pressure gets built up, heat will raise like crazy. You need to have case fans to keep everything moving and keep the air circulating. Also, with no fans, your processor fan uses the same hot air over and over, but with case fans, it gets new cooler air.

Crazy how much of a difference it makes eh?
Both cases have front fans, I thought that was enough. But... I'm still using those ribbon IDE cables. Too lazy to get a SATA hard drive, or use those round cables.
 

Wayniac

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Snump said:
Both cases have front fans, I thought that was enough. But... I'm still using those ribbon IDE cables. Too lazy to get a SATA hard drive, or use those round cables.
It also depends how they're set. You usually want the front as intake and back as exhaust. If they were both set to one direction then pressure might have been building up, or if one is exhaust and one is intake, your airflow could have been pretty goofy giving you hot pockets in your case.
 

Snump

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Wayniac said:
It also depends how they're set. You usually want the front as intake and back as exhaust. If they were both set to one direction then pressure might have been building up, or if one is exhaust and one is intake, your airflow could have been pretty goofy giving you hot pockets in your case.
Right, I knew that. I just thought that with front fans blowing in, the air would shoot out the back thanks to the power supply fans. What's funny is, I have both PCs on the floor on a rug, crapped into a desk compartment. There's about half an inch between the two of them - plenty of room behind though, with my UPS right next to them as well. This is temporary. Even with that the temp hangs around at 60 to 62 under distributed.net's full load.
 

SHAWN

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I dont know what my rig runs at but i have 2 80mm fans in the rear, 1 on the door, 2 in the front and one 92mm pointing down from my PSU. All I know is that when i touch my hard drives and under the heatsink, its warm not hot. I can hold my fingers there for as long as i wanted to.
 
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