Advice on optimizing my A7N8X-dlx

[geronimo]

It has a XP 3000 CPU, and two Corsair XMS 512 mb ddr 3200 (400 Mhz)
SDRAM (operating single channel). Initially it was set for "optimal"
(slowest). I think it said CPU speed was 1050 Mhz. I changed to custom
(I think it ws called). I bumped the FSB to 220 (more or less) and
bumped up mulitiplier to 12.5 (the highest you can select).
Now when it boots, it STILL says the CPU speed is 1050 Mhz and the RAM
speed is 100 MHz. I thought the CPU speed was supposed to be 12.5x 220
which is 2750 Mhz. Whats up with that? Shouldn't I be able to get a
lot more than 1/3 of the rated max CPU speed? I have experienced a
couple of blue-screens in the two days since doing this, so perhaps
it is at the max. The core voltage is set to 1.75, BTW. THe CPU has
a hefty Volcano 9 on it. What max performance should I be able to get
out of it?

 

[Dave]

It has a XP 3000 CPU, and two Corsair XMS 512 mb ddr 3200 (400 Mhz)
SDRAM (operating single channel). Initially it was set for "optimal"
(slowest). I think it said CPU speed was 1050 Mhz. I changed to custom
(I think it ws called). I bumped the FSB to 220 (more or less) and
bumped up mulitiplier to 12.5 (the highest you can select).
Now when it boots, it STILL says the CPU speed is 1050 Mhz and the RAM
speed is 100 MHz. I thought the CPU speed was supposed to be 12.5x 220
which is 2750 Mhz. Whats up with that? Shouldn't I be able to get a
lot more than 1/3 of the rated max CPU speed? I have experienced a
couple of blue-screens in the two days since doing this, so perhaps
it is at the max. The core voltage is set to 1.75, BTW. THe CPU has
a hefty Volcano 9 on it. What max performance should I be able to get
out of it?

The clock speed of that cpu is about 2167MHz. I think that should be about
13 X 166MHz. I wouldn't expect it to run at all if you crank up the FSB
to 220. But that still wouldn't explain why the CPU is showing 1050MHz at
POST. Clear CMOS settings and then load default. -Dave

 

[Paul]

It has a XP 3000 CPU, and two Corsair XMS 512 mb ddr 3200 (400 Mhz)
SDRAM (operating single channel). Initially it was set for "optimal"
(slowest). I think it said CPU speed was 1050 Mhz. I changed to custom
(I think it ws called). I bumped the FSB to 220 (more or less) and
bumped up mulitiplier to 12.5 (the highest you can select).
Now when it boots, it STILL says the CPU speed is 1050 Mhz and the RAM
speed is 100 MHz. I thought the CPU speed was supposed to be 12.5x 220
which is 2750 Mhz. Whats up with that? Shouldn't I be able to get a
lot more than 1/3 of the rated max CPU speed? I have experienced a
couple of blue-screens in the two days since doing this, so perhaps
it is at the max. The core voltage is set to 1.75, BTW. THe CPU has
a hefty Volcano 9 on it. What max performance should I be able to get
out of it?

Clocking a processor, should be done like "sneaking up on it". You make
changes in small steps, then observe the results and work from there.

Selecting a ridiculous overclock level will result in the board
crashing in the BIOS. Asus has an overclocking recovery feature,
which will return the settings to safe defaults, so you can enter
the BIOS and make more adjustments. When you see the low frequency
values, that is what has happened. The board crashed, and has
recovered automatically for you. (My board has failed to recover
from an overclock only once, forcing me to clear the CMOS. So the
automatic recovery feature seems to work pretty good.)

There are two Barton 3000+ processors.
You have the 200MHz one (the top one here).

Barton 2100MHz (3000+) OPGA 200 512 10.5x 1.65V 85oC 53.7W
Barton 2167MHz (3000+) OPGA 166 512 13x 1.65V 85oC 58.4W

If the clock after the crash recovery is 100, and the multiplier is
the 10.5 default, then the observed value of 1050MHz is correct.
You need to move the clock from the crash recovery value of
100MHz, up to 200MHz in small steps. You can start by trying 133MHz,
and see if it survives that. Check that the core voltage setting
is in the correct range (1.65V setting, 1.69V or so measured).
When idle, the motherboard will overvolt by a tiny bit, which is
normal for Asus boards, and is part of their interpretation of
the correct load line.

When you are finished, you should be at 200 x 10.5 . That would give
the correct nominal value of 2100MHz. And it should say 2100MHz
in the BIOS.

Changing the multiplier in the BIOS works, if you have an old
processor. Processors after a certain production date are locked.
Mobile processors (I have one in my A7N8X-E) also allow the
multiplier to be set in the BIOS. If you change the multiplier
value, and are still seeing the effects of the 10.5x nominal
multiplier, that should be a hint to you that the processor is
locked.

In terms of other potential issues, be aware that Nforce2 is
picky about the RAM. I had problems with the first RAM I
had in the board, and after a lot of testing, it turned out
the RAM had a bad location. After I put a couple sticks of
Ballistix PC3200 CAS2 in the board, it was rock solid. And
remains that way to this day. Using "good RAM" compensates
for the barely adequate performance of the I/O pads on the
Nforce2 Northbridge.

If you are having trouble with your RAM, go into the BIOS
and set the memory to "Manual". The speed settings
offered should be percentage values. A value of "100%" is
the same as operating synchronous with the FSB. If you
select a value of "83%", that is usually enough to bring
stability. If you still experience crashes, try cranking
the RAM down to 83%. If you want to run at 100%, that
may take some "good RAM".

And be careful with that memory setting. Do *not* use 50%
or 200%. There have been failures after doing that. So don't
go near the extremes. Like the CPU clock, try small
deviations from 100% and see how it goes.

Paul

 

[geronimo]

THe maximum FSB setting I could get out of mine was only 172 with 10.5
multiplier. If I go to 173 or higher, after the desktop has been
dispalyed for about 1 minute, the computer completely shuts down.
This is really lousy. I have a 3 gig CPU, but it will only do 1800 in
my system! My CPU is not lockedat least, it is reporting 1806 mhz on
the POST.

I thought surely that Corsair XMS 3200 was in the "good" if not "best"
category! SO I guess I should try backing down from 100% memory
speed...but if I have to back that down to 80% in order to go up 14%
(to 200) on the FSB speed, have I really gained anything in
performance?

Thanks much...that was just the info I needed! Geronimo

 

[geronimo]

I should have added that I have two sticks of 512 mb ram. THis board
doesn't operate DDR. I have been told. I think that leaves one mem.
slot open? If it is picky about location, then I should try moving the
ram sticks, too?

 

[Paul]

I should have added that I have two sticks of 512 mb ram. THis board
doesn't operate DDR. I have been told. I think that leaves one mem.
slot open? If it is picky about location, then I should try moving the
ram sticks, too?

The A7N8X-X is the board that doesn't run dual channel. I think
all the rest do support dual channel. All boards of that family use
DDR (dual data rate) memory. (The Nvidia chipset that is single channel,
is Nforce2 400. I think the Nforce2 Ultra 400 is still dual channel.)

That board operates relatively independently, of which slot is left open.
Each of the three slots, has a private address bus. And that is what
allows independent operation.

If I had to make a choice, while using two sticks, I'd do it like this.
These two sticks are sitting next to the termination resistors.

------
------ <--- Put one stick here

------ <--- Put one stick here

I've thoroughly tested the operating conditions for that chipset.
The chipset "resists" any config that gives performance, if your
RAM is not to its liking. For example, if you plug the memory in
a single channel configuration, it will allow a higher clock value.
But single channel doesn't give quite as much bandwidth. It can
also be made stable, by selecting "83%" in the BIOS for the memory,
but that too also robs you of performance. You can also use a
hacked BIOS (I've used Trats BIOS for example). Using a Command
Rate 2T version of the BIOS, allows 35MHz or so more clock to be
used. But, as you would expect, Command Rate 2T also subtracts
the very same 35MHz worth of performance. So there is no getting
around a memory problem.

Paul

 

[Paul]

THe maximum FSB setting I could get out of mine was only 172 with 10.5
multiplier. If I go to 173 or higher, after the desktop has been
dispalyed for about 1 minute, the computer completely shuts down.
This is really lousy. I have a 3 gig CPU, but it will only do 1800 in
my system! My CPU is not lockedat least, it is reporting 1806 mhz on
the POST.

I thought surely that Corsair XMS 3200 was in the "good" if not "best"
category! SO I guess I should try backing down from 100% memory
speed...but if I have to back that down to 80% in order to go up 14%
(to 200) on the FSB speed, have I really gained anything in
performance?

Thanks much...that was just the info I needed! Geronimo

Check the heatsink. The stock heatsink can mount two ways. One way
is a 180 degree rotation of the other way. The "contact patch" on
the bottom of the heatsink, is offset. When installed the wrong
way, part of the silicon die is exposed to the air. That can lead
to the worst kind of overheating for the die (overheating plus a
temp differential across the silicon die).

Asus motherboards of that era, have thermal protection. A small eight
pin Winbond chip, senses the temp diode on the silicon die of the
processor. If the processor gets too hot, the Winbond chip is suppose
to shut off the computer.

So recheck your heatsink mounting. Make sure there is sufficient
thermal paste, that the heatsink is parallel to the board, and that
the heatsink is rotated the right way (so the contact patch is
centered over the silicon die). If you are lucky, it'll stop switching
off.

Also make sure that the amount of Vcore voltage, is not out of line
for your processor.

Paul

 

[geronimo]

Well, Sounds like you're right that the winbond chip is shutting the
PC down from overheat, as I wasn't getting crashes, the PC would just
with no warning shut down about when the desktop was finishing
boot-up. SO I took the Volcano 9 fan/heatsink off. ( have added one
of those clear elbow ducts on top of the fan, BTW) and checked out
alignment. The bottom copper surface on the Volcano 9 is many times
bigger than the copper CPU die, and the die is very near centered.
ALso from the way the grease was squished down on the heatsink I could
tell that it was in contact with the entire surface of the die. Its
not Artic silver paste, but it is a GC white colored grease that is
supposed to have very high thermal conductivity.
So it doesn't seem that there was any mechanical problem with the
heatsink/fan that was causing a problem. I reinstalled Asus Probe,
and checked what the temp is with the PC idling at desktop. It is 107
CPU and 98 deg. mobo temp. I think this is very good....so why is it
behaving like it is an overheat shut-down?