Problem for the hardcore techies & jury riggers.

[The Rock]

Gotta problem. I FINALLY found out why I've been having trouble overclocking my last 2 processors with my Asus P2B (P2 350 / P3 450). Most people seem to be able to run the P3 450 at much higher speeds: well, not me. I bumped er up to 504 (112x4.5), and it ran fine for a day. Then my machine beeped a few times and froze solid (heat I presume?). So one day I'm messing around inside my case with my machine powered up and I notice (HOW did I miss this before) that my power supply is blowing hot air RIGHT ON TO MY CPU! (duuuhhhh...wonder where the heats coming from ). Even though I have a fairly big fan sucking air out the back of the case, it appears this ain't enough. THIS is my problem: I can't simply flip the power supply upside-down due to the design of the case since it has an unremovable "roof" on it (it's a minitower case BTW). So what can I do? IS there anything I can do besides buy a better case?


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The Rock
Home Machine: P3 450 + 128 Meg PC100 RAM + 23G Storage
Work Machine: IBM OS/390 + 10Gigs RAM + 1.5 Terabytes Storage (and no damn AGP slot...what a waste)

[Jake]

Yes, you could simply take your PSU apart and reverse the fan. Be careful though not to touch any of the components inside the PSU. They could retain current. ZAP! No fun getting electricuted!

Regards,

Jake

[Rags]

The ATX specification calls for the PS to blow down on the cpu. Most overclockers know that, by reversing your PS fan, you can get your CPU quite a bit cooler. My temp went down 10 degrees when I reversed mine.

Rags

[Buuri]

Also note that many power sources have air holes around it so reversing that fan still causes some warm air to circle in the case. In AT systems that's not an issue while in most cases the fan is in the back, but not in ATX.
I can't say if taping those holes is a wise thing to do. I know I haven't dared, 'cause I'm afraid that it'll heat up too much then..

_
B

[Fred]

What kind of RAM are you running? What speed? What stepping of PIII 450 do you have? What cache speed? Apparently the KC0 stepping PIII are easily OC'ed, I have mine running at 558, no problems attributable to the oc, the CPU generally runs at about 43 to 53 degrees C. I have an Antec dual fan heat sink on it, with a few other fans nearby, but I don't think they make much of a difference. It may be your RAM or PCI bus that doesn't like to be OC...

[Brian R.]

If you don't fell comfortable with reversing the fan, another alternative is to buy a new power supply. They remove and install quite easily.

[The Rock]

Fred:

I have NO idea what stepping of P3 450 I have; how do I find out? I'm using standard PC100 RAM (unsure of brand), and I assume my cache speed is 1/2 of CPU speed (225). Another crappy deal is that I can't monitor my CPU temperature since I don't have any kind of thermal sensor. I'm gonna hafta find one somewhere. Thanks for all the replies.



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The Rock
Home Machine: P3 450 + 128 Meg PC100 RAM + 23G Storage
Work Machine: IBM OS/390 + 10Gigs RAM + 1.5 Terabytes Storage (and no damn AGP slot...what a waste)

[Kruzin]

The P2B is very easy to add a heat sensor to for the CPU. The plug is there on the mobo already. Just go to radio shack and buy a thermistor, and wire it up to an old speaker plug. Works great, and cost $0.89. Pisses me off that Asus didn't spring the big bucks for that component (their cost woulda prob been a whole 5c), and include it with the mobo

[The Rock]

Kruzin:

Thermistor eh? Wouldn't I have to wire it to the same kinda plug that the P3 CPU fan has in order to connect it to my mobo? And would I be able to get a temp reading through Asus PC Probe software?

The Rock

[Fred]

Check out http://www.firingsquad.com/guides/p3overclocking/

It's a good guide about stepping numbers. When I asked about cache speed, I was referring to the ns (nanosecond) speed of the RAM, it's on the cache chips, but the guide goes into this as well. As far as the thermal sensor, I was referring to the diode that is (I think?) on all P3's and most Celerons, I guess your motherboard has to support it. I have the Asus P3B-F, and I use the Asus Probe utility and it will give me the CPU and MB Temp. Take a look in the BIOS for something called Hardware Monitoring, enable it, if you can (if it's there...). Your memory may not like to be OC as well. Many use PC133 SDRAM, I have PC100, and am running at 124Mhz, but your mileage may vary.

HAve a look at that site, it should answer all your questions

Fred

[Kruzin]

Not a fan plug. A 2-wire speaker plug is what I used on my P2B, and it works just dandy. And yes, this allows the P2B's PCProbe software and bios to monitor that temp. The plug on my mobo is between the AGP slot, and PCI1...there is a 3-wire connector (for wake-up on LAN...which my 3com NIC is hooked to), and a 2-wire for the temp probe...

[The Rock]

I'll give er a whack and see what happens. Thanks for all the info guys.



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The Rock
"The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: His eyes are closed."
-- Albert Einstein