Are AMD Athlon 64 Socket 939 processors with 4 double sided DDR400 modules in dual channel mode limited to DDR333?

Hello all!

In the manual of the MSI K8N Neo2 Platinum Mainboard (Socket 939, nForce 3
Ultra chipset)
it says that if you fill up all banks using four double-sided DDR400
modules, that the
Mainboard can only operate in DDR333 in dual channel mode. I read the same
in many reviews of the board and other Athlon 64 Socket 939 boards.
The articles say that it is a current limitation to the Athlon64.
Since my old mainboard has died and I wanted to upgrade my CPU anyway, I
thought I would still go for the aforementioned board and an Athlon 64
3500+, even
though I have got four double-sided Twin-Mos DDR400 modules. As expected
from the reviews, it was working with DDR333 in dual channel mode.
So I was thinking that I could try overclocking my Athlon 64 3500+, as the
memory shouldn't have any problems with it until it reaches 200MHz, so I
tried a FSB of 119 which brought the processor up to 3800+ speeds (2400MHz),
as I read on the web it should make that easily with stock cooler and I
thought it should do it with a Zalman CNPS-7000ACu. At the bootup screen,
the memory was shown as running at 181MHz. However, the computer would hang
while booting Windows XP. The same thing happened, no matter how little I
overclocked the FSB (I have Dynamic overclocking disabled and the AGP speed
locked at 66MHz and default voltage for CPU, memory and AGP). What could be
the problem here? It seems as the memory is not.
Anyway, I thought I won't be overclocking for now, so I checked all BIOS
options again. I noticed I could set my memory clock up to 200MHz
and I thought I'd give it a try, even though the reviewers state it won't
run in dual-channel DDR400 mode with four double-sided modules. I boot up
and lo and behold, the system runs in DDR400 dual channel mode with the RAM
running at 200MHz, at least according to the bootup screen.
The system boots into Windows and is perfectly stable no matter what, but
due to the reviews stating it shouldn't work, I am wondering, is it really
running in dual channel DDR400 mode for all four modules? Has anybody else
had experience with this? Is there a tool that can tell me reliably what
speed my memory is running at and if it's in dual channel mode or not?
And if it is, what about all the articles on the net and my mainboard manual
that
state it isn't possible?

Thanks in advance,

Glzmo

"Ed" wrote in message
...
On Sun, 03 Oct 2004 11:12:07 GMT, "Glzmo" wrote:

Hello all!

In the manual of the MSI K8N Neo2 Platinum Mainboard (Socket 939, nForce 3
Ultra chipset)
it says that if you fill up all banks using four double-sided DDR400
modules, that the
Mainboard can only operate in DDR333 in dual channel mode. I read the same
in many reviews of the board and other Athlon 64 Socket 939 boards.
The articles say that it is a current limitation to the Athlon64.
Since my old mainboard has died and I wanted to upgrade my CPU anyway, I
thought I would still go for the aforementioned board and an Athlon 64
3500+, even
though I have got four double-sided Twin-Mos DDR400 modules. As expected
from the reviews, it was working with DDR333 in dual channel mode.
So I was thinking that I could try overclocking my Athlon 64 3500+, as the
memory shouldn't have any problems with it until it reaches 200MHz, so I
tried a FSB of 119 which brought the processor up to 3800+ speeds
(2400MHz),
as I read on the web it should make that easily with stock cooler and I
thought it should do it with a Zalman CNPS-7000ACu. At the bootup screen,
the memory was shown as running at 181MHz. However, the computer would
hang
while booting Windows XP. The same thing happened, no matter how little I
overclocked the FSB (I have Dynamic overclocking disabled and the AGP
speed
locked at 66MHz and default voltage for CPU, memory and AGP). What could
be
the problem here? It seems as the memory is not.
Anyway, I thought I won't be overclocking for now, so I checked all BIOS
options again. I noticed I could set my memory clock up to 200MHz
and I thought I'd give it a try, even though the reviewers state it won't
run in dual-channel DDR400 mode with four double-sided modules. I boot up
and lo and behold, the system runs in DDR400 dual channel mode with the
RAM
running at 200MHz, at least according to the bootup screen.
The system boots into Windows and is perfectly stable no matter what, but
due to the reviews stating it shouldn't work, I am wondering, is it really
running in dual channel DDR400 mode for all four modules? Has anybody else
had experience with this? Is there a tool that can tell me reliably what
speed my memory is running at and if it's in dual channel mode or not?
And if it is, what about all the articles on the net and my mainboard
manual
that
state it isn't possible?

Thanks in advance,

Glzmo


http://www.memtest.org/ (stand alone memory tester, run from bootable CD
or Floppy)

http://www.mersenne.org/freesoft.htm (set to Stress testing only, run
torture test-Test Lots of Ram).

http://www.cpuid.com/cpuz.php (CPU-Z, see Memory tab for single/dual
info.

hth,
Ed

Thank you very much for these links. I did all those tests the whole night
and everything went error free and stable. CPU-Z also tells me all my memory
is running 200MHz in dual channel mode.
I'm glad it works out fine. I still wonder what's up with all the reviews
claiming it shouldn't work, though.