Abit BF6 and PIII-450 OC'ing. Need advice...

[Jake]

Hi!

Well I finally got around to exchanging my venerable BH6 for a BF6 as my BH6 did not provide a 1/4 divider at 133Mhz bus speed which REALLY overclocked my PCI bus. The BF6 does and I had hoped to run my PIII-450 at 600 Mhz as I think my system components should be able to handle that speed.(The PCI bus will run at the default 33Mhz speed). My G200 is able to run 100 Mhz (agp setting 1/1) even in x2 mode for that matter (READ 200 Mhz!!). So it should be able to run 87Mhz (2/3*133). But alas my PIII-450 was unable to go beyond the 558 Mhz I was running before without seriously upping the voltage. Here's some info:

124: 558@2.0V
125: 562@2.05V
126: 567@2.1V
127: 571@2.2V
128-133: 576-600@2.3V

Also my CPU temp in the bios differs a lot from what I get with HWDoctor, Sandra99 or MBM 4.13.

At 558 Mhz my CPU temp reading in the bios shows 60C and 37C in HWDoctor!

At 600 Mhz 80-85C, 45-50C respectively. Anyone else get this difference?

I tried upgrading to the latest bios from Abit only to find that they had changed the default I/O voltage from 3.3V to 3.5V. Anyone know why? I flashed it back to the PO version...

What I really need is your expert advice on some cooling sollutions to get to 600 Mhz stable. I have allready replaced the standard fan/heatsink with a dual fan GlobalWin 5000rpm heatsink. I didn't help one bit. It was running just as stable at 558 with the regular fan/heatsink.

I think I read somewhere that it was possible to "grind" something off the top of the CPU (on the old PIII's that is) to allow for better heat transfer to the heatsink. Anyone know the exact procedure? Also my GlobalWin heatsink comes attatched with a thermal pad in the place that makes contact with the cpu. Should I remove it and try some other kind off heat conductant like thermal paste (the white goo)?

Any input is much appreciated.

Regards,

Jake

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Who is General Failiure and why is he reading my drive?
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MGA-G200 8Mb Mill. bios ver. 2.3, Abit BF6 mobo bios ver. PO, PIII-450@558, 128Mb PC-133 SDRAM, 17" Hitachi monitor, Plextor 40TS CDROM, Panasonic 7502 CDR. Diamond MX300 A3D PCI soundcard.


[This message has been edited by Jake (edited 18 February 2000).]

[Compton]

Did you try disabling your L2 cache? Of course you don't want to run all the time without cache but it might be worth testing. If you can run at 600+mhz 2.0V without it then you'd know what is holding you back. I dont think you want to do any sanding on a P3, I thought that was mostly for ppga celerons. Definately use thermal paste instead of the pad. You can get some for real cheap at radio shack. I've heard that the globalwin stuff is pretty good but if you think it's not helping very much then try an Alpha cooler. I have an Alpha heatsink on my celery with a YSTech fan spinning at 9000rpm and it really does the job. As for the temperature differences I have no idea, I don't trust them too much. I just stick my tongue against the heatsink and if it burns then it's too hot.

[Jake]

No, I haven't tried disabling my L2 cache, but now that you mention it I will.
And I know that Alpha heatsinks rule supreme, but they cost a ton of dough to get shipped from the states, and no Danish retailer I know of carries them. I think GlobalWin are considered "hardcore" in Denmark and the retailers think they provide suffucient cooling for the masses. Sucks bigtime!

I will try removing the thermal pad and use some paste in stead.

Watch out with that tongue trick! You might get 3rd degree burns! At least I would if the 85C I get from the bios is correct.

Thanks,

Jake

[birdy]

I have exactly the same cooler as you and I was not able to oc any higher than the 600 i had with the std HSF. One thing i did notice with the cooler is that the area which is in contact with the cpu is not smooth, there are ripples in it. Realising that this would not be good for heat transfer i sanded it flat to an almost mirror finish. I still could not clock any higher but it did drop the cpu about 3c under load.

Also with my cpu i found that it actually clocks better with lower voltage. I run mine at 1.9v.

Make sure your memory can handle 133 and also make sure that at this speed you have it set at cas3 hardly any memory will run at 133 with cas2

As with any overclocking expedition, make sure your case is well cool. No matter how good the heatsink is it wont get the chip below the temperature within the case. I have the ability to turn my fans on and off, when i run the machine with them off the temp withn the case shoots to 40c and i start to get program errors. With them on it stays a nice cool 28 and is more stable than a Vulcan with four legs.

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p3 450@600. bx6 ver 2. 128mb unbranded pc100. iwill 2930u scsi, diamond pro pci modem, advansys 1505 isa scsi, SB Live!, pioneer dvd103s, hollywood plus dvd card, plextor 40x cd rom, ricoh 1420 cdr, ibm 13.5gb @ 7200rpm, G400 @ max settings. All wrapped up in a big case with loads of fans. Belinea 10 30 40 17" monitor

[Dyre]

I just recieved the new globalwin CPU cooler and this thing is a BEAST! I havent dont much testing but it looks like a VERY high quality unit with some masive YS-Tech fans. I believe it is the VOS32 and they are avaiable at <a href="http://www.thecardcooler.com">The Card Cooler</a> forabout $30(US). I would try sanding down your current HSF and try to get some copper spacers to go between the cache chips and the HSF.

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PIII 450 @ 504
generic BX motherboard
G400 MAX : )
Maxtor 13 gig UDMA 33
Maxtor 13 gig UDMA 66
Creative 36x CD-ROM
HP 2x2x6x CD-RW
64 megs PC100 RAM
128 megs PC133 ECC RAM
NetGear 10/100
Soundblaster 32 AWE
Diamond SupraExpress 56k
Logitech Wireless Desktop (best $50 ive ever spent)
1 92mm Sunon Fan
4 80mm Sunon Fan's