Hello,

I have an AMD Athlon XP 2200+ CPU and a MSI KT6V (MS-7021 v1.X)
ATX mainboard. The KT6V mainboard is based on VIA KT600 North Bridge
& VT8237 South Bridge chipset.

I bought a 1GB DDR400 module recently. When I tried to use it with
my 512MB DDR400, BIOS could detect only 1.25GB, so 256 MB
was missing. 512MB module or 1GB module work quite fine separately
and BIOS detects the correct amount.

My motherboard has two slots and I also switched the slots I've used
for 1GB and 512GB (i.e. I tried 1GB in the first slot first and then I
tried in the second slot) but I again had 1.25 GB.

According to the motherboard's manual, the motherboard supports
DDR DIMMs up to 400 MHz, it supports 1GB modules and it supports
2GB at maximum.

Apart from this problem, 1GB memory module seem to work slower
with compared to 512 + 256 = 768MB I had before. By working slow
I mean, winamp getting stuck while playing mp3s even when I have
only the browser open and before it didn't to that at all even when
there were many programs opened at the same time. What can be
the cause for this? FSB is set to 133 MHz, so I wonder if DDR266
or DDR333 DIMMs are more suitable for this speed. After all,
isn't maximum speed for DDRs are 266 MHz, if the FSB is set to
133 MHz?

Even though my motherboard's manual (http://tinyurl.com/ypzu3t)
tells that I can use DDR400 modules up to 1GB, Kingston's website
doesn't recommend 1GB DDR400 at all. http://tinyurl.com/2huvo2

I bought the 1GB memory module from a big computer shop and
the memory module was sold with the computer shop's name.
But the OEM seems to be Elixir and the module is
M2Y1G64DS8HB1G-5T. You can find a pdf file about the module
at http://tinyurl.com/29ayf5.

There is one more person with the same mainboard experienced
slow down in memory when he upgraded this memories:
http://tinyurl.com/yrq6jr

Here you see a pdf file about some memory tests done for my
motherboard: http://tinyurl.com/269hy7

Thanks in advance,
-Baris