A7N8X-VM/400 - it's official, Asus' most memory fussy mobo (long)

In article omain,
Stephen SM WONG writes
So, how do you run your 400MHz RAM at 333MHz? I'm curios.
There's almost nothing one can tweak in the BIOS, in terms
of timing.

I can't agree more the board is fussy. Mine is an older
version A7N8X-VM, and I'm consider to buy a replacement main
board, say a Gigabyte or something. Anyway, I'd owned more
than 10 Asus main boards, A7N8X-VM is the only one make me
disappointed, I was thinking that it was a bad sample. But
it does give me quite some headache.

My 2 cents.

Stephen Wong @ Hong Kong

Hi Stephen,

VM/400 only supports 333MHz mem max so it defaults to 333 even when
you put in 400MHz memory. I'm thankful for that small bit of sense in the
bios rather than some 'not supported' beep message. I think your VM (not
/400) did support PC3200 at the full 400MHz, albeit a limited range of
qualified memory.

This is my first Asus & probably my last. If I need to iron out problems with
little support from the mfr, I'd prefer not to pay a premium for the privilege.
I'll take my chances on the cheapies in future.

If I do any further playing with this board it may be by reprogramming the
profile of the EEPROM on the memory sticks - as a round about way
fooling the bios into making timing changes. Don't ask me how yet, it's just
an idea ;-)
--
fred

In article , zzipper
writes
A friend of mine bought one of these as well, his fix was if you use the
onboard graphics use only one stick of ram. Dual channel only seems to work
if you install an AGP card. He had no problems at all with it once he was
using a single stick.

Made no difference to my setup, memtest86 was error free with the two
256M sticks for a good 12hrs and prime95 stable for about the same with
onboard graphics but with acceleration turned off . There appear to be no
hard & fast rules, other than that the memory is right on the edge on this
one.
--
fred

wrote:
A friend of mine bought one of these as well, his fix was if you use the
onboard graphics use only one stick of ram. Dual channel only seems to work
if you install an AGP card. He had no problems at all with it once he was
using a single stick.

This didn't work for me. One stick, Corsair Value Select 256mb 333MHz,
failed in exactly the same way as with two sticks.

--
Callas

I have a problem with this board which may be unrelated, but then
again...

I am using two sticks of Kingston 256Mb value ram and an Athlon XP2200+.
When the computer is first started-up the cpu temperature as reported by
the BIOS fluctuates wildly, like: 23C, 45C, 44C, 97C, 2C, 26C, 42C, 50C,
109C (these are examples of the reported temps in Celcius once a
second). Of course the ASUS C.O.P. protection cuts-in and turns off the
system. Obviously these temperatures are not what's really happening
with the CPU - there's no way it can fluctuate that rapidly.
And yes, I've re-seated the heatsink with new thermal compound, used
bigger fans on the heatsink, etc, etc.
Using a single stick of ram instead of two gave no improvement.
If the computer manages to run a few minutes without the C.O.P.
switching it off, the cpu temperature reporting in the BIOS stabilises
at around 45C. This indicates to me that something on the motherboard,
ram or CPU is stabilizing and that it is an elctronic problem rather
than thermal.

Any clues as to what's going on please?

fred wrote:

In article omain,
Stephen SM WONG writes
So, how do you run your 400MHz RAM at 333MHz? I'm curios.
There's almost nothing one can tweak in the BIOS, in terms
of timing.

I can't agree more the board is fussy. Mine is an older
version A7N8X-VM, and I'm consider to buy a replacement main
board, say a Gigabyte or something. Anyway, I'd owned more
than 10 Asus main boards, A7N8X-VM is the only one make me
disappointed, I was thinking that it was a bad sample. But
it does give me quite some headache.

My 2 cents.

Stephen Wong @ Hong Kong

Hi Stephen,

VM/400 only supports 333MHz mem max so it defaults to 333 even when
you put in 400MHz memory. I'm thankful for that small bit of sense in the
bios rather than some 'not supported' beep message. I think your VM (not
/400) did support PC3200 at the full 400MHz, albeit a limited range of
qualified memory.

This is my first Asus & probably my last. If I need to iron out problems with
little support from the mfr, I'd prefer not to pay a premium for the privilege.
I'll take my chances on the cheapies in future.

If I do any further playing with this board it may be by reprogramming the
profile of the EEPROM on the memory sticks - as a round about way
fooling the bios into making timing changes. Don't ask me how yet, it's just
an idea ;-)
--
fred

In article ,
writes
I have a problem with this board which may be unrelated, but then
again...

I am using two sticks of Kingston 256Mb value ram and an Athlon XP2200+.
When the computer is first started-up the cpu temperature as reported by
the BIOS fluctuates wildly, like: 23C, 45C, 44C, 97C, 2C, 26C, 42C, 50C,
109C (these are examples of the reported temps in Celcius once a
second). Of course the ASUS C.O.P. protection cuts-in and turns off the
system. Obviously these temperatures are not what's really happening
with the CPU - there's no way it can fluctuate that rapidly.
And yes, I've re-seated the heatsink with new thermal compound, used
bigger fans on the heatsink, etc, etc.
Using a single stick of ram instead of two gave no improvement.
If the computer manages to run a few minutes without the C.O.P.
switching it off, the cpu temperature reporting in the BIOS stabilises
at around 45C. This indicates to me that something on the motherboard,
ram or CPU is stabilizing and that it is an elctronic problem rather
than thermal.

Any clues as to what's going on please?

First of all, this is not my area of expertise, but here is my best shot:

The rapid fluctuations in reading suggest that this is not a problem with
your heatsink (or memory), but a fault in the CPU temp sensor or in the
mobo monitoring chip/connections. I don't think there is anything more you
can do other than RMA the board/cpu. Try the CPU in another board or
another CPU in the mobo to narrow down the fault.

You may get more help by stating a new specific thread or by doing a
google groups. My quick search suggests that all modern Asus/AMD
boards use the same 'COP' mechanism, so there should be plenty of info
out there.

HTH
--
fred

Careful when using this mobo with integrated graphics (which was probably
why you wanted to buy it). Memory timings when system memory is
shared with the integrated graphics processor are far tighter than when a
plugin agp card is used.

I'm running cheap & cheerful 400MHz ram at 333MHz and figured the
underclocking would leave me a healthy timing margin. It does, 24hrs of
memtest86 and 12hrs of Prime95 suggest it's solid, but run anything
graphics intensive, like a movie, and it falls flat on it's face. Symptoms
are
typical of interaction between graphics & system accesses, corrupted
stripes in the display, then the inevitable crash as a crucial area of
system
mem is corrupted. Ok, I've got cheap memory, but use a plugin agp card
and it's solid as a rock - seems a little unfair.

Asus uk tech support are patient & helpful, but basically they say go &
buy premium memory, which memory you ask, as there is currently no
approved memory list for this board. He suggests I visit my friendly local
retailer and try premium memory brands until I find one that works.

After a long call (friday afternoon) the support guy's resolve falters; he
says:

1. This board was never intended for public sale
2. It was produced at the request of large OEMs to satisfy the need for
simple, fully integrated boxes.
3. It is their most memory fussy board ever.
4. When the pet OEMs ran into memory problems they were asked which
memory they would like to use and the board/bios was tweaked to suit.
5. There is no publicly available list of the memory that this board has
been
tweaked to work with.
6. A user tweakable bios is not in the pipeline for this board

I'm not prepared to take the risk of buying more memory without a
guaranteed fix so I'm using the known fix of a plugin agp card. It is now
solid, cheap memory and all.

Thought I'd make life simple this time, pay the premium, buy the big name
and go for integrated graphics, I won't be making that mistake again.
--
fred

I'm just trying to put a system together with one of these boards too.
I have formatted the hard drive and get halfway through Windows XP Pro
installation, and the system just reboots, then the message "setup is
restarting" appears and it's back to "39 mins to go".
Thiis is the first thread I have looked at regarding this board, so will it
be the cheap and cheerful memory that's causing this as well? (I
deliberately bought 333 and not 400 because I read that the onboard graphics
preferred 333).

Peter

In article , Peter
writes


I'm just trying to put a system together with one of these boards too.
I have formatted the hard drive and get halfway through Windows XP Pro
installation, and the system just reboots, then the message "setup is
restarting" appears and it's back to "39 mins to go".
Thiis is the first thread I have looked at regarding this board, so will it
be the cheap and cheerful memory that's causing this as well? (I
deliberately bought 333 and not 400 because I read that the onboard graphics
preferred 333).

Peter

This forum entry is a fair summary of the current situation with this board:
http://www.abxzone.com/forums/showth...5fbfc26ad5abcc
675c4bbae45e1&threadid=67997

Perhaps try a run of memtest86 overnight to see if you have any chance of
making it work. If it doesn't run clean then that would be a good excuse to
rma the whole lot and start again with another mobo - hopefully you bought
all the bits from the same retailer.
--
fred

I'm just trying to put a system together with one of these boards too.
I have formatted the hard drive and get halfway through Windows XP Pro
installation, and the system just reboots, then the message "setup is
restarting" appears and it's back to "39 mins to go".
Thiis is the first thread I have looked at regarding this board, so will
it
be the cheap and cheerful memory that's causing this as well? (I
deliberately bought 333 and not 400 because I read that the onboard
graphics
preferred 333).

Peter

This forum entry is a fair summary of the current situation with this
board:
http://www.abxzone.com/forums/showth...5fbfc26ad5abcc
675c4bbae45e1&threadid=67997

Perhaps try a run of memtest86 overnight to see if you have any chance of
making it work. If it doesn't run clean then that would be a good excuse
to
rma the whole lot and start again with another mobo - hopefully you bought
all the bits from the same retailer.
--
fred

Thanks for that Fred. In the end I returned the generic memory and bought
"Crucial" instead. Needless to say it is now running flawlessly.
Thanks for your reply.

Peter