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couple o' fan questions

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Jan 12, 2002
down at fraggle rock
ok, i'm running an xp 1700+, radeon 8500, sb xgamer, 256mb DDR, and a dvd/cdrw drive on a 300 w PSU.

Currently i have 1 80 mm fan plugged into the mobo and the CPU fan is plugged into the PSU via a molex adapter. I am planning to add 1 or 2 80mm side fans, a 60mm exhaust fan on the back, and a ram cooling fan if my PSU can handle it. So basically what I want to know is: what is a safe number of fans that can be run off a 300w PSU? I have molex adapters for these so they'll be run off the PSU and not the motherboard.

Also, what's a good setup for the side fans? should I have one blowing on the radeon and another blowing on the CPU fan?

anyways, the dragon orb's about to come off so i can replace it with a millenial glaciator....hopefully this airflow will drop my temps from 42c that i'm seeing right now to something nice and frosty.


Mar 12, 2002
Raleigh NC
I'll get some disagreement here but here i go anyway.
As for the umber of fans, just keep adding them until you see a voltage drop on your 12v line, thats what molex connectors use. It all depends on the draw each fan has too, so you cant have a set number.
As for the side fans, if the glacior draws air out from the top you dont want another fan blowing in on it. If it blows down onto the HS, I cant imagine much help comming from another fan above, fan stacking works, but only to a point. Maybe move that fan so its more over then RAM then CPU if you really want two side fans. And yes the other over the VCard is a good idea, though if it has a nice fan maybe drawing out would help dissapate the heat already drawn out by the gpu HSF. It would only take 2 seconds to try both ways, so to your own test and see which yields better results. Hope I helped.



Mar 27, 2002
I have a Tbird 1.4 [email protected] 1.667 w/ MSI K7T266a pro2-ru. I use a volcano 7 HSF. I get 46 C under load and 40 C at idle with [email protected]. 37 C with [email protected] volts.
The key to my temps is the ported duct I put over the HSF fan. It draws cool outside air in right onto the heatsink. Looks great too. That duct dropped my temps by 15 degrees compared to running the machine without it and with the case open! email me by clicking on my profile button if you want pics of what it looks like and how to do it. This will negate the need for another fan on the side since the cpu fan will be pulling the air in. Just a word on fan usage too...If you have 2- 40cfm fans, one pulling in and the other pushing out your total airflow through the case is only 40cfm not 80cfm. Also if you "stack" those same 2 fans one directly on top of the other you will not get any more airflow than with just one. The reason: the top fan pulls 40cfm in to the bottom fan. The bottom fan can only move 40cfm so by feeding air faster into it will not result in more cfm out of the bottom one. it will remain the same. In fact it can actually make it worse. If the fans are not exactly the same make and model and/or they do not turn in perfect synchronization what may happen is as the top blades turn and force air out the fan blades in the fan beneath it may be in the way of those swooshes of air(lack of a better term)and therefore deflect the air back at the top fan. Use your imagination as to what happens after that. I hope thats not too confusing, just my 3 cents.