bluesman24/7 said:
I'm trying to run my A7N8X-x/barton xp 2500 combo at 400fsb. The MB will
post but Windows will not boot. I have 2x512 Corsair pc3200 cas 2.5. Any
ideas why Windows won't load? Thanks
The stock speed for your 2500, is 166x11. By raising the FSB to
400, you are asking for 200x11, which is the speed of a 3200+.
This constitutes overclocking (you didn't mention it in your
post, and I'm assuming that you knew that is what you were doing).
This should not be a big deal, except you might want a bit more
Vcore.
XP Model 10 1833 (2500+) OPGA 166 512 11x 1.65V 85oC 53.7W
XP Model 10 2200 (3200+) OPGA 200 512 11x 1.65V 85oC 60.4W
To find some info on typical experiences, visit this site, and
select "Barton 2500+" in the AMD section.
http://www.cpudatabase.com/index.cfm?action=search
Now, it is hard to draw conclusions from data in a listing like
this. There are 632 entries, and for some of them, the people
making the entry, might not have tried to overclock very hard.
But, if you look at enough entries, and throw out the outlying
data points (because idiots put nonsense entries in the
database), you'll see some trends.
There is a fair spread on the Vcore people are using. Translated
another way, there is a spread on how overclockable a processor
can be. In some previous plotting of datasets from this database,
I've seen a spread of around 500MHz in how overclockable a
processor can be. You can see in the Barton 2500+ list, that
some people didn't make it to 2200MHz (3200+ performance level)
and that really surprises me. Maybe that will be your fate - it
could be your processor really is not a good overclocker. But
I'm willing to bet, that a little extra Vcore might do the
trick.
According to the Barton datasheet, the absolute maximum Vcore
you can apply would be 1.65V + 0.050V + 0.5V = 2.2V. The VID
codes go to 1.85V, and your processor could be getting a bit
warm at that point anyway.
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF
The average for the 632 entries is 2314MHz, according to the
database. A better way to judge them, is plot frequency versus
Vcore applied, and see the trends.
To make sure the memory is not a problem, try just one stick
of memory. Nforce2 is picky about memory, and it could be the
memory is what is killing you. If I were you, I would have
a memtest86+ test floppy in hand, crank the motherboard clock,
then test the memory. There is no sense booting Windows, if the
memory is throwing errors. Do your "tuneup" with memtest86+,
when you've reached what looks like a stable overclock, zero
errors in a couple complete passes of memtest86+, then try
booting Windows. If you still have problems with the single
stick of RAM, try setting the memory to "83%", which will run
the memory at DDR333 while you are using your FSB400 (200MHz
clock) setting. Once you've investigated how overclockable
the core of the processor is, you can return to working on the
memory issues (for me, the solution was to buy some CAS2
memory - that fixed all my problems on an A7N8X-E Deluxe).
While the A7N8X-X is a single channel motherboard, the layout
of the board says otherwise (there are two sets of termination
networks next to the DIMM slots), and it could be you'll
experience the same issues as you would see on a dual channel
board. Also, give the memory a little extra Vdimm, like
maybe 2.7V, as that will help if the performance is
marginal.
When overclocking, there are no guarantees when it comes to your
disk drive. People routinely lose all their data while fooling
around with overclocks. An experienced overclocker will either
do a complete backup of their disk, before an overclocking run,
or they will use a separate boot disk they can afford to lose.
Fooling around with live (non-backed up) data is not a wise
thing to do. Once you've run Prime95, 3DMark, SuperPI, your
favorite 3D game, and they are stable, then would be a good
time to put back the original boot disk with your valuable
data on it.
HTH,
Paul
