The front side bus speed for each chip might differ and therefore that might be the reason the PIII 1000 MHz doesn't work on your motherboard.

Wait...just checked ABit's site here are the specs:

1. Supports Intel Pentium® III 450~800 MHz processor cartridge based on 100 & 133 MHz FSB
2. Supports Intel Pentium® II 233 ~ 450 MHz processor cartridge based on 66 & 100 MHz FSB
2. Supports Intel Celeron® 266 ~ 533 MHz processor based on 66 MHz FSB
3. Reserves support for future Intel Pentium® III processors

It only goes up to 850 MHz PIII no matter what. So even if you underclock the 1000 MHz chip, it probably still won't work, even if the 1000 MHz chip is flip-chip or slot.


But...I could be wrong. Most of my experience lies with Pentiums, Celerons, PII, and some AMD K6 and Athlon. Not much with PIII or PIV.

Oh well...that's my two cents. Good luck!