I purchased a PIII 866/256/133/1.7v (MALAYSIA) at a computer fair recently. I intended it to be a modest upgrade to the CPU I have at present in a home built ABIT VH6T APOLLO 133A based PC (with soft menu). I intended just to swap with the existing CPU, a PIII 800/256/133/1.7v (COSTA RICA), which I intended to use in another computer. I was dismayed when the computer would not boot (into the bios setup) at all. The monitor remained blank. I replaced the previous CPU and the computer booted. I next put the PIII 866 in a slot 1 to socket 370 converter card which I placed in an Abit BX6 REV 2 motherboard based PC. It was on autodetect and when it booted up it was identified as a Celeron 566MHz with the FSB at 66MHz. This equates to a multiplier factor of 8.5. This CPU is supposed to be a PIII 866MHz with a (fixed) multiplier of 6.5 and FSB of 133 producing the 866MHz. I booted into Windows 98 and ran the Intel CPU ID utility. It confirmed the Celeron 566 MHz rating, which it said was also the expected rating. I next set the jumpers on the the Slocket III converter card to the fixed 133MHz FSB rating and rebooted. The BX6 REV 2 PC would also not boot at 133FSB. I next set the jumpers on te converter card to produce a 100MHz FSB and rebooted. The PC did boot and the CPU was identified as a Celeron running at 850MHZ (meaning a 8.5 multiplier). After Windows booted I ran the Intel CPU ID utility again and it confirmed the CPU was a CELERON running at 850MHz but that it was now overclocked and the expected rating was 566MHz at 66MHz FSB. I decided to try again with the VH6T PC. However before replacing the existing PIII 800MHz cpu with the PIII 866MHz, I set the FSB speed in the softmenu to 66MHz. I then shut down and changed over the CPU's. This time the computer booted and the CPU was identified again as a CELERON (running at) 566MHz. The Intel utility confirmed the processor was a Celeron running at 566MHz and was ruuning at the expected speed. Finally I set the FSB to 100MHZ in the bios and rebooted. The CPU was identified as a Celeron (running at) 850MHz, which the Intel utility confirmed, as well as reaffirming that it was overclocked at this speed. I should be very gratefull if anyone could offer an explanation as to why a CPU with Pentium III 866MHz (printed)on it,(multiplier 6.5), is identified as a Celeron 566MHz (multiplier 8.5). I sent an email to Intel and was directed to some links, but these did not seem relevant. Thank you.

sSpec Number SL4NW Processor Frequency 566.00 MHZ CPUID String 0686 Package Type 370 pin PPGA FC-PGA1 Core Voltage 1.700 Bus Speed 66 MHz Thermal Guideline 11.9W Core Stepping cC0 Thermal Spec 90°C L2 Cache Size 128 KB Manufacturing Technology 0.18 micron L2 Cache Speed 566.00 MHZ Bus/Core Ratio 8.6 ------------------------- sSpec Number SL5DX Processor Frequency 866.00 MHZ CPUID String 068A Package Type 370 pin PPGA FC-PGA1 Core Voltage 1.750 Bus Speed 133 MHz Thermal Guideline 26.1W Core Stepping cD0 Thermal Spec 80° C L2 Cache Size 256 KB Manufacturing Technology 0.18 micron L2 Cache Speed 866.00 MHZ Bus/Core Ratio 6.5

uh...maybe someone pulled the old switch-a-roo?

What does the alledged "P3 866" look like? Does it have a small rectangular purple/blue core on it, with a green PCB base, or does it have a rather large square silver core with a black PCB base?

Thank you all for your replies. Actually the CPU SL No is SL4CB which I did check on the Intel Spec Finder List at their website. It seemed to co-relate with what is on the black identity strip at the bottom of the CPU. As regards the "old switch-a-roo" suggestion, this could explain it all, but would it have been done for a single (or very small number of) CPU('s)? I have not read, either on the net or in computer magazines, of any fraudulent PIII's circulating, which surely would have come to light well before now, as the CPU has been out a while. It all looks genuine enough. Apart from the country of origin (Malaysia) it looks exactly like my PIII 800 (country of origin Costa Rica) viz. green PCB base with blue/purple core approx. 12mm x 10mm in size. I suppose there could have been the occasional genuine labelling mistake at the factory? Regards briang.