"matrix" said:
To the experts,
Is is possible to use a PIII 667Mhz 133FSB Slot 1 CPU on an ASUS P2B
motherboard even though the particular motherboard was designed for a PII
Slot 1 CPU? If yes, can I expect reliable performance?
Thanks for the help.
AGP divider = 1/1 or 2/3. 2/3*133 = 89MHz, suitable for older video
cards but not an ATI9800 or FX5900 type card. Some of
the latest cards max out at 75MHz. Some of the old
Geforce cards can do 100MHz.
Check to make sure CPU frequency settings are there for 133MHz.
My P2B-S, for example, only goes to 112MHz, as the clock gen won't
do 133MHz.
If you look up your purchase on processorfinder.intel.com, and
either look in the Pentium3 section, or search via SSPEC (SLxxx)
code, you'll find the processor probably runs on less than
1.8V. This means you would need a revision of P2B motherboard
with a voltage regulator that works at lower than 1.8V.
The workaround for this, is to modify the VID code sent by the
SECC module to the motherboard, by means of cutting tracks
to change a VID from 0 to 1, and adding grounding wires, to
make a VID code 1 into a 0. You want to send a VID code for
1.8V to the motherboard, instead of the 1.65V or slightly more
that the processor is probably requesting. A slocket with VID
switches or jumpers makes this easy, but then you are searching
for a slocket (like an Upgradeware slocket) plus a S370 packaged
Coppermine processor.
Life is a lot simpler, if your motherboard has a voltage regulator
that handles VID codes for less than 1.8V.
So, yes, a slot 1 module will work, but depending on the Vcore
regulator and the clockgen chip on the board, there could be
challenges. Typically a voltage regulator with a B in the
part number, will do less than 1.8V. (For example, on my
P2B-S motherboard, a HIP6004A is 1.8V min, while HIP6004B
will do less than 1.8V, and the latter one is suitable for
higher Coppermines or Tualatin processors.)
Searching in Google, on P2B and either 9150 or 9250, will give
some info on clockgen chips.
ICS9150-08: not guaranteed over 112MHz operation, too slow.
ICS9250-08: supports 16 FSB settings between 66.8Mhz and 150.0Mhz
ICS9250-18: supports 32 FSB settings between 66.9Mhz and 166.0Mhz
Datasheets for clockgen chips are available at icst.com .
If you post the revision number printed in white letters on your
motherboard, maybe we can help you further. Or use the revision
info and read this page. Without some info on exactly what hardware
your motherboard has on it, we'll end up writing a book for you
http://homepage.hispeed.ch/rscheidegger/p2b_procupgrade_faq.html
I hope you did the "homework assignment" from my previous post
HTH,
Paul
