On Mon, 13 Oct 2003 16:41:38 +0000 (UTC),
Here's a more ambitious upgrade idea for my Kayak XAS -- a socket 370 to
slot 1 converter to put something like a PIII 850 MHz in it, which still
has a 100 MHz bus.
Yes, that's another alternative, but you might as well shoot for
something higher than an 850, either a 1GHz, 950, Celeron 1.1GHz, or
an Upgradeware type adapter to run a Tualatin Celeron or PIII.
The reason I always read that Coppermine processors
can't be used is because they use a different voltage, but if that's the
only reason, a different VRM can be plugged in and the problem will be
solved!
Just about any ADJUSTABLE voltage regulator (need not be
user-adjustable, only sensing the CPU voltage "automatically") will
support down to 1.8V. This is true of motherboards in general, but
I'm not as confident it applies to VRMs. Even on VRMs that don't
officially support a Coppermine's 1.5V-1.75V Vcore, there might be the
option to use 1.8V... that's low enough to be safe for a Coppermine
CPU, but requires a sloket adapter with a voltage jumper to set 1.8V
(or some CPU pin wire-mods or slotket modifications). This part of it
is certainly doable given the time to work out any issues if/as they
arise.
I'm trying to find pinouts for HP and others' VRMs to form an
opinion on compatibility.
It's quite likely you won't find these pinouts. Once you have a VRM,
if you can provide very detailed pictures of it or the markings on
some of the chips I "might" be able to tell what voltage range it
supports, but of course there's only so much confidence I can have
over usenet, not having the part(s) in front of me. At least by
looking at the controller used on the VRM, the maximum voltage range
possible can be determined.
But are there incompatibilities besides the VRM? A limitation of the
chipset or of the motherboard? If the BIOS is updated for a PIII 600MHz,
will it automatically run the PIII 850MHz, or will it need another update
that can only come from HP, and which HP might not have?
Yes, there are other potentials for incompatibilties. The chipset,
being a BX, isn't one of them, it's known and proven to work with
Coppermine P3/Celerons.
The BIOS is the major issue, above all else. Without a supportive
BIOS the system may not even POST with a Coppermine P3 in it.
It is possible HP added Coppermine support to the BIOS, possible that
the BIOS would work without this specific support, but on the other
hand, it's also possible the BIOS would halt when it couldn't ID the
CPU, would've worked except that it "unnecessarily" halted itself.
There might be a BIOS setting to adjust this halt behavoir, but I
wouldn't count on it, generally such systems have lesser flexibility
when it comes to CPU upgrades.
The last part of what you wrote pretty well sums up the situation,
that it might work with the last BIOS, or might not, and if not, you'd
need a BIOS from HP that did add (allow) Coppermine usage, which may
not exist. If you do try it you should update the BIOS before
swapping the CPU, or just swap the old one back in then update it.
Dave