Wow CPU temp major drop off. Does 35C sound better than 78? And what's safe for a K7 .25um

[Noriaki]

Some one you may remember my panic from the other day when my athlon was reading 78C.
Well..I found 3 things wrong with that cooling I had (or didn't have)

[*]There was a GAP between my heatsink and heat transfer plate..ouch, in fact is was a big enough gap that I could comfortably fit a thermal probe in it without squeezing.
[*]There was no thermal grease at all, not that it would have helped with the last point
[*]I had a wimpy little heatsink with a single dinky little maybe 40-50mm fan.

All that left me at 78C with RC5 running...not surprising...god damn it how could they even sell a CPU with that kind of cooling..

Anyhow now I got an Alpha P7125 with dual 60mm 26CFM YS Tech fans and thermal grease. I'm running at a much nicer 35C...
(this is with the thermal probe slid down between the PCB and the heat transfer plate because I have no cover on my athlon)

So now that I have it at a reasonable temperature, how high is safe to run it up to (I have a GFD )

Thanks in advance, and extra thanks to everyone that helped me with the P7125 assembly.

 

[Dulanic]

You lucky... I had a gap between my FOP 38 and my 800 T-bird and it went toasty within 15 seconds.

 

[Noriaki]

I only had a gap at the top maybe it was new.....I just noticed it today..I think the bottom half was touching...though not well...
78C is plenty toasty for me...



Damn these guys generate heat fast.
It's a 550, and at 550 it was 35C, at 600 it's 42-43C

700 wouldn't POST at 1.6V (not that I really expected it to), what's the default voltage for a 700Mhz Athlon .25um ?

 

[Noriaki]

Ack so much for my grand overclocking plans.

I have a 550 .25um Athlon classic, it's running at 600Mhz 1.6V (default) seems happy enough. It will not fully load win2k at 650 at 1.7V...

Hrmm...do you guys think I'll be able to push it any more? 1.75V maybe?
I'm not sure how high I want my Vcore to go...

 

[Fardringle]

As long as your temperatures stay reasonable (and they should with that new heat sink) you will probably be fine going as high as 1.85v, but I'd move up in the smallest increments you can until you get the stability you want, then increase the multiplier again, and increase the voltage again, until you get to a point where you either can't go any higher, or you are satisfied with what you have...

 

[corkyg]

I have found that anything under 55° C is green. I like it under 40° C.

 

[SDTom]

How far your 550 will go depends on a lot of things, cache chips, L2 divisor, true core speed, vintage of chip, etc.

It sounds to me that you may have one of the older .25 cores, they do run warmer than the later week .25 hybrids and do not OC quite as high as the later chips.

The stock cache chips on a 550 are the 3.6 ns. they will max out around 650 - 700 at the stock 1/2 L2 divisor.

My guess is that you may need up to around 1.8v to get 650 stable if it is one of the older stock 550 cores.
It may be also that the very high temps you were running may have taken a toll on the chip and will limit your success.

What is the serial number of your chip? It can be found on the top edge of the case or also on the white sticker found on the back of the PCB.

Tom

 

[ltk007]

With that alpha you might be able to get it as high as 700 if your cache chips are good enough. You should probably only increase the voltage to 1.9 at the most, anything higher and you are likely to fry it. Even 1.9 is a little high, although that's what I run mine at. There's no way to know how high you'll get it without try, so give it a shot and tell us what happens.