Underclock an XP-M?

Are there any Asus microATX boards w/a bios that will allow
a range of adjustments to an Athlon Mobile?

I've read that the Asus boards do not recognize an XP-M.

But do they allow for any range of adjustments to its FSB,
memory, and voltage?

In contrast, it appears that a board like the ChainTech 7NIF2
may have a bios that will allow many adjustments.

I prefer Asus, but I need to get as much number crunching
as I can while staying w/a low power, quiet system.

--
George Newton

In article , George Newton
wrote:

Are there any Asus microATX boards w/a bios that will allow
a range of adjustments to an Athlon Mobile?

I've read that the Asus boards do not recognize an XP-M.

But do they allow for any range of adjustments to its FSB,
memory, and voltage?

In contrast, it appears that a board like the ChainTech 7NIF2
may have a bios that will allow many adjustments.

I prefer Asus, but I need to get as much number crunching
as I can while staying w/a low power, quiet system.

Things an Asus full sized ATX board won't do:

1) Allow undervolting. If the BIOS misidentifies the processor,
it won't allow you to set extra low voltage. Even though the
Mobile might be rated to run at 1.45, you won't be setting
that in the BIOS.
2) As a rule, the hardware support for multipliers, is missing
FID4. Now, I just read tonight, that the A7V880 properly
supports multipliers, so if you wanted higher than 12.5x
that might be a candidate. But, before you buy, you will
need to track down and verify whether a "wire trick" will
be needed for a particular model of board. (My A7N8X-E,
for example, doesn't drive FID4, so for high multipliers,
I'd need the wire trick.)

Item 2 is necessary for old older boards that cannot handle an
FSB of greater than FSB266. With such a board, a high multiplier
is needed to get to 2GHz. So, on those older boards, a wire is
needed to program FID4, to enable the high multipliers. (That
is the so-called "Wire Trick".) On boards that work at FSB400,
200x12.5 would be the highest Fcore you could get with the low
multipliers. If you wanted to go higher, you'd need a board that
supports all multipliers (like the A7V880 I saw mentioned), or
you'd need the wire trick. [A picture of the wire trick to get
multipliers above 12.5 - the so-called high multipliers.]
To do 200x12.5, you would likely need at least 1.65V, so missing
low VID adjustments for such a high overclock is not an issue.

http://img49.exs.cx/img49/8428/13multi2.jpg

In my experience, there is not much gain in performance by
going that high, and the processor is going to get pretty
warm, if set to do 2.5Ghz. Your choice of course.

Things an Asus microATX board won't do:

1) Same problems as the full sized board as listed above.
The BIOS lacks adjustability, and a microATX is not a good
platform to start with. Download the PDF manual from the
download page, and inspect the pictures of the BIOS screens,
for evidence of adjustability.

Software tools like CPUMSR can also be used to change the multiplier
when booted into Windows. Presumably, what would happen, is the
computer would boot at 600 or 800MHz or so, then you would
use this program to set the multiplier register inside the
Mobile processor. This program doesn't work with all chipsets,
so have a look at the FAQ first.

http://www.cpuheat.wz.cz/html/AXP_mu...iplier_FAQ.htm
http://www.cpuheat.wz.cz/html/main.htm (CPUMSR download)

Check some forums for information on the various motherboard
makers boards. Since the Asus microATX boards are not really
intended for enthusiasts, I think you will be happier with another
brand of board that more fully supports VID adjustments and
maybe even a full set of multiplier adjustments, without the
need for a wire trick.

AMD motherboards (must register to use search engine)
http://forums.pcper.com/forumdisplay.php?f=21

Nforce2 boards:
http://www.nforcershq.com/forum/search.php

A7Vxxx family boards:
http://www.a7vtroubleshooting.com/fo...;action=search

In the worst case, you can get whatever VID you want, by
wiring directly to the Vcore regulator chip, and programming
the five bit value there. At least one modder has done that,
to get the ultimate control (no BIOS interference possible,
once the Vcore control pins are lifted off the board :-) .

I use a Zalman 7000Alcu on my A7N8X-E, and that is one way
to keep the temps down, with reasonable noise level.

HTH,
Paul

On Mon, 28 Feb 2005 01:46:04 -0500, (Paul) wrote:

Things an Asus full sized ATX board won't do:

1) Allow undervolting. If the BIOS misidentifies the processor,
it won't allow you to set extra low voltage. Even though the
Mobile might be rated to run at 1.45, you won't be setting
that in the BIOS.

In the BIOS it won't, but in Windows, with 8rdavcore, my M2500+ doing just
fine at 1.45V (actually 1.46-1.47 because of Asus add).

http://www.home.fh-karlsruhe.de/~wis...ove-giveio.zip

read tips&tricks


--
DOWN WITH SIGNATURES!

(Only for this occasion)

Thanks for your info and suggestions.

--
George Newton