[luau] Underclocking

[MonMotha]

Comments inline.

R. Scott Belford wrote:
>>*Via C3 - says it needs a fan, but apparently they were designed to be
>>used with a heatsink only
> 
> 
> This is an intriguing chip that I came across a few weeks ago in my search to 
> build the coolest possible POS box.  I like it very much and will be testing 
> it alongside of a few celerons.  Maybe I will try it without a fan.
> 

As I said, I think the engineering docs say a fan is not needed, but 
make sure you watch the temp probe while you have it off (and make sure 
the case has good airflow; the heat has to go somewhere).  Also remember 
that C3s aren't fast. I've heard 1/2 the MHz to get a PIII comparible 
figure...OUCH!

> 
>>I've seen numerous Pentium IIs and some Pentium IIIs running with
>>just a heatsink and using fan ducting to blow air across it.
> 
> 
> My favorite two boxes use an older slot PII and Celeron.  The Celeron runs 
> fanless, 24/7, in a debian box.  It's got a decent graphics card and is good 
> enough for the rare Xwindows browsing and emailing.  Very cool box that has 
> run for a few years (touchwood) straight here in humid Hawaii.  The PII box 
> has run just as long, but it does have a CPU fan.  Both use the 440BX chipset.
> 
> The registers across the island that never give me any trouble after years of 
> continuous and poorly ventiliated service are based on the Intel 440BX 
> chipset.  Aopen still sells what may have been its greatest motherboard with 
> this chipset
> 

The BX was a great chipset.  I actually have my PIII 1GHz on one of 
those bad boys.

> http://www.aopen.com/products/mb/ax6bcproii(m).htm
> 
> I have opened cases to find pounds of dust, a stalled cpu fan on the PII 350, 
> but stable performance nonetheless.  This can be the platform for a cheap, 
> stable, and maybe even fanless desktop if it is silence that you seek from 
> your computer.  I know that you are working with an Athlon and and Asus 
> mboard already, so this may not be very relevant.  I love these older 
> motherboards so much, though, that I had to share my measly $.02.
> 
> scott
> 
> 
> 
>>especially if your PSU blows
>>hot air inward (as reccomended by the ATX spec) rather than outward
>>(what most PSUs do in white boxes).  
> 
> 
> I didn't know that was the spec.  It completely defies the logic of 
> facilitating the escape of the already rising hot air by blowing outward.  I 
> usually add a few case fans to blow inward and help force the hot air out the 
> top through the PS.  Perhaps I should re-think this.  Very interesting.

The idea was to eliminate an extra fan, and this was back when CPUs 
could have warm (but not hot; notice how OEMs use small power supplies 
when they do this?) air blown across them and still be effectively 
cooled.  Obviously you can see the reasons why most white box PSUs are 
done differently (even my old PII-300 Dell has a PSU fan that blows out 
and a case fan behind the fanless heatsink on the PII).

--MonMotha