14 Sep 2004, 20:31, mark lewis (1:3634/12), wrote to Tom Walker:

Hi mark.

 ml> FWIW: proper ATX power supplies pull fresh air thru the power 
 ml> supply and blow it directly across the CPU assembly... exit ports 
 ml> in the case vary from there... true ATX power supply fans are not 
 ml> accessible from the back of the case, either...

 ml> unfortunately, many ATX power supplies are simply reworked AT 
 ml> power supplies and do continue to do things the old way...

Not really.  The original ATX design was for 200MHz CPUs which had bare
heatsinks located just below the PS fan, which was on the bottom of the PS
and inside the case.  Every one of those we built self destructed within
warranty.  I thought it was a pretty dumb idea to have the fan at the hot
top of the case blowing in and down.

As soon as the Intel CPUs began arriving with their own built-on fans, it
was no rocket science to see that the PS fan was blowing into the CPU
heatsink fins opposing the built-on fan.  I started removing all the
blow-in fans and reversing them, then we had no more problems.

Now that CPUs are up to several GHz, it's more important than ever to get
the hot air OUT of the case, and that hot air is naturally at the top.


     Good luck...  M.

--- Msged/386 TE 06 (pre)