ASUS P4S800 and ram problem

I have put a computer together using the ASUS P4S800 motherboard and a P4
2.8 Prescott cpu. When this was done I only had one stick of 512Mb DDR400
ram in slot 1 and XP Pro loaded as the OS. The computer appeared to work
well and did everything I wanted it to do almost instantly.
This morning I tried to add another stick of identical ram to give me 1Gb
and dual channel if it does dual channel. That is where it went pear shaped.
If I try to use ram slots 2 or 3 it plays merry hell and reboots or won't
boot at all.
I have tried single sided ram in pairs and double sided ram in pairs but the
rotten thing will not allow me to use slots 2 and 3.
Is there a driver I should be using and I don't know about as this is my
first time straying away from AMD stuff?
The parts were second hand from different friends and I had to update the
BIOS before it would recognise the Prescott cpu.
PSU is 500 watt so I don't think it is a lack of power problem and I suppose
it is possible that two of the ram slots are dead.
Any ideas appreciated here thanks.

Venom wrote:
> I have put a computer together using the ASUS P4S800 motherboard and a P4
> 2.8 Prescott cpu. When this was done I only had one stick of 512Mb DDR400
> ram in slot 1 and XP Pro loaded as the OS. The computer appeared to work
> well and did everything I wanted it to do almost instantly.
> This morning I tried to add another stick of identical ram to give me 1Gb
> and dual channel if it does dual channel. That is where it went pear shaped.
> If I try to use ram slots 2 or 3 it plays merry hell and reboots or won't
> boot at all.
> I have tried single sided ram in pairs and double sided ram in pairs but the
> rotten thing will not allow me to use slots 2 and 3.
> Is there a driver I should be using and I don't know about as this is my
> first time straying away from AMD stuff?
> The parts were second hand from different friends and I had to update the
> BIOS before it would recognise the Prescott cpu.
> PSU is 500 watt so I don't think it is a lack of power problem and I suppose
> it is possible that two of the ram slots are dead.
> Any ideas appreciated here thanks.
>
>

Move the good stick, to slot 2 or slot 3. Since that stick of memory worked
in one slot, it should also work in the others. No sense adding a second stick
of RAM, unless you can prove the other slots work.

The motherboard has three slots, and is single channel. Adding sticks in
pairs will not give dual channel operation, a boost in bandwidth or the like.
All that adding sticks will do, is increase the total amount of RAM.

http://www.asus.com/products.aspx?l1=3&l2=12&l3=48&l4=0&model=206&modelmenu=1

Once you've determined all the slots work, with your good stick, you can test
with the second candidate. Try the second candidate in the known working
slot first, all by itself, to see if it works or not.

When installing two sticks in a three slot board, I would try slot 1 and
slot 3. That spreads the capacitive stub loading a bit, and makes a marginal
improvement in bus reflections.

The other thing you can try, when two sticks are present, is changing the
memory clock. If the thing appears to be unstable at DDR400, try DDR333
if the motherboard supports async options. Some motherboard manuals will
even warn that the speed should be dropped when using more than one stick
at that speed. (The two single sided DIMMs should have made it easier
to get it to go, though, so maybe that is not the entire problem.)

So I think you still have a few test cases to run, to try to narrow
down the problem. I'd also try looking on the vip.asus.com forums, and
see how much trouble people have had with RAM on that board.

HTH,
Paul