First post, by kool kitty89
Can normal P55C processors be used with the AdvancedML board? It's an HX board, but seems to lack split-rail voltage. In fact, I can't seem to find any mention of adjustable I/O voltage support either (just 3.3V, no 3.52, etc) given the technical info here: http://www.bcmcom.com/tech/sq598/28180602.pdf
However, it does seem to functionally work with MMX chips, just at the expense of overvolting them (or using the 3.3V specced POD W/MMX) and I even see some mentions of Marl systems using 233 MHz parts, like this: http://alasir.com/software/ramspeed/logfiles/p55c-430hx.html
OTOH, I also found this old thread warning against using MMX parts with the board:
http://groups.google.com/group/intel.motherbo … a814bab29c9a35a
The Intel(R) Advanced/ML motherboard commonly referred to as the Marl does not support the Pentium(R) processor with MMX(TM) tec […]
The Intel(R) Advanced/ML motherboard commonly referred to as the Marl does not
support the Pentium(R) processor with MMX(TM) technology. It does not have
support for the split plane voltage. The core of the MMX(TM) processor is 2.8
volts unlike the normal Pentium(R) processor, which is around the 3.3 volt
range. It is possible to cause damage to the processor and or the motherboard.
The upgrade path for this motheboard would be the 200-MHz Pentium(R)
OverDrive(R) processor with MMX(TM) technology, the part number for this
processor is BPODPMT66X200. You also may want to check the motherboard for the
AA and or PBA number on a sticker on the motherboard itself to ensure that this
is the Intel version of the Marl motherboard and re post with those numbers so
we can check for you.
But, to be honest, this sounds more like a straight quote from intel literature rather than practical advice on the subject. Ie, not officially sanctioning running parts out of spec, as most firms will do for liability reasons (same for overclocks, etc).
From what I gather, the Pentium MMX Overdrive is really the same 350 nm chip as the stock P55C, just with additional testing to clear it for official 3.3V operation and a different thermal envelope and many normal MMX parts wil work perfectly fine at 3.3V (not to mention overclockers boosting voltage for other reasons). Granted, the chips will certainly run hotter (just like the MMX OD), but still not very warm even by standards of the time.
3.3V isn't really pushing it for normal 350 nm chips in general either, the late model P54Cs were 350 nm too, plus the Winchips all specced at 3.52V, and of course the K6-233 specced for 3.1~3.3V.
Other than that, the Advanced/ML seems like a great platform for the P55C with the high-end 430HX, albeit with the 128 MB RAM limit, and still better than VX or TX boards there since it can cache all 128 MB.
Edit: I see I was wrong about the POD-MMX, it does actually use an onboard voltage regulator rather than running natively at 3.3V, though this does still seem a bit excessive for that type of chip. (certainly not like the case of running 3.3V 486 parts in 5V boards)