C0deHunter wrote on 2021-12-16, 08:02:
Believe me, I mention it numerous times:
Board revision 1.04
BIOS revision 1006
The magic word here is "Coppermine"
There are three completely different kinds of P3:
- Katmai
- Coppermine
- Tualatin
The Katmai is basically just a P2 with some instructions added. Hardware that can support Deschutes P2 can always support Katmai (although firmware i.e. BIOS might be an issue on some boards). Coppermine is a completely different beast. Instead of 512kB external L2 cache on separate chips running half speed, it contains 256kB of internal L2 cache running at full speed. That improves performance significantly. And - and this is your problem here - it had a die-shrink which made it more electrically efficient and operate at lower voltages. And your motherboard needs to support those voltages.
Asus made a royal mess of revisions of the P2B, with Coppermine-capable VRMs found on some from 1.05 onwar but only reliably present on 1.12. One place they aren't though is 1.04. So your board can't deliver 1.65V. What does it do if your CPU asks for it anyway? Design states if an unsupported voltage is requested, it doesn't supply anything. That's what's happening here, regardless of BIOS.
So what can you do?
- in-spec you can replace the P3-650E with a P3-600 Katmai (note: not 600B, which requires 133MHz FSB, or P3-600E which is also a Coppermine, or P3-600EB, which is both) or lower that requests and runs on voltages supported by the board.
- you can modify the pins on the CPU to request a slightly higher but hopefully not damaging voltage that the board can supply (1.8V)
- you can replace the slot 1 P3-650E with an So370 P3-650E (or higher) and connect it using an So370 FC-PGA (yes, there are also three different kinds of So370 and you specifically need this one) to Slot 1 slocket that offers voltage jumper settings, where you can set jumpers to do the same as modding the pins as suggested above.
- you can try and replace the onboard VRM itself for newer version that can do 1.65V. This requires quite a bit of (de)soldering skill.
As for the BIOS, so long as the multiplier of your CPU is 10 or below (on a P3-650E it's 6.5), the system will at least boot with an unrecognized CPU, but if possible you want to get upgraded to have the correct microcode for the CPU - but once again, that's not the big issue here, it's the voltage.
For more info, take a look here:
https://web.archive.org/web/20191114013933/ht … pgrade_faq.html