Memtest-86 errors in dual-channel mode for nforce2 system

I have a Biostar M7NCD Pro (nforce2) motherboard as the basis of my
homebuilt. It has been running without a hardware problem for about 11
months.

I've used five different PC2100 sticks of various sizes and
manufacturers in many combinations, in the Biostar and in a Dell 4500
(P4, Intel 845 chipset).

Yesterday the system hung several times, requiring reboots. So I did
some testing of all five sticks with Memtest-86.

The Biostar has three DDR slots, named B1, B2, and A1. To get dual
channel, you have to fill A1 and at least one of the B slots. I find
that there are Memtest-86 errors if and only if I configure the RAM as
dual channel.

So would it be a motherboard problem, specifically a memory controller
problem? The CPU is an Athlon XP 2500+ Barton, and the PSU is an Antec
SL350. What are the chances that there is involvement of the CPU or PSU?

"anybody" wrote in message
...
I have a Biostar M7NCD Pro (nforce2) motherboard as the basis of my
homebuilt. It has been running without a hardware problem for about 11
months.

The Biostar has three DDR slots, named B1, B2, and A1. To get dual
channel, you have to fill A1 and at least one of the B slots. I find
that there are Memtest-86 errors if and only if I configure the RAM as
dual channel.

What are the memory settings in the BIOS set at?

Any overclocking involved?

If everything is set stock, I would suspect that the mainboard was bad.

BTW, is PC2100 the correct speed for the XP2500+ on this mainboard?

Noozer wrote:
"anybody" wrote in message
...

I have a Biostar M7NCD Pro (nforce2) motherboard as the basis of my
homebuilt. It has been running without a hardware problem for about 11
months.


The Biostar has three DDR slots, named B1, B2, and A1. To get dual
channel, you have to fill A1 and at least one of the B slots. I find
that there are Memtest-86 errors if and only if I configure the RAM as
dual channel.


What are the memory settings in the BIOS set at?


I guess you could say it's all stock. I don't understand much about
memory settings, so I didn't mess with it.

FSB: 166
Memory Frequency: By SPD
Resulting Frequency: 133
Memory Timings: Optimal
RAS-RCD-RP-CAS: 6-3-3-2.5

I have the choice Auto/By SPD for the Memory Frequency. I don't know
what is best for that.

Any overclocking involved?

I've had the CPU multiplier bumped up to 12.5 from the default (11, I
believe), and it ran fine and gave a nice little speedup all the while.
I put it back to default when the problem appeared.


If everything is set stock, I would suspect that the mainboard was bad.

BTW, is PC2100 the correct speed for the XP2500+ on this mainboard?

Well I can't say, but it's the only RAM I have, so ...

anybody wrote:

I've had the CPU multiplier bumped up to 12.5 from the default (11, I
believe), and it ran fine and gave a nice little speedup all the while.
I put it back to default when the problem appeared.

I mean _after_ the problem appeared.

On Fri, 03 Sep 2004 03:17:26 GMT, anybody
wrote:

Noozer wrote:
"anybody" wrote in message
...

I have a Biostar M7NCD Pro (nforce2) motherboard as the basis of my
homebuilt. It has been running without a hardware problem for about 11
months.


The Biostar has three DDR slots, named B1, B2, and A1. To get dual
channel, you have to fill A1 and at least one of the B slots. I find
that there are Memtest-86 errors if and only if I configure the RAM as
dual channel.


What are the memory settings in the BIOS set at?


I guess you could say it's all stock. I don't understand much about
memory settings, so I didn't mess with it.

FSB: 166
Memory Frequency: By SPD
Resulting Frequency: 133
Memory Timings: Optimal
RAS-RCD-RP-CAS: 6-3-3-2.5

I have the choice Auto/By SPD for the Memory Frequency. I don't know
what is best for that.

Any overclocking involved?

I've had the CPU multiplier bumped up to 12.5 from the default (11, I
believe), and it ran fine and gave a nice little speedup all the while.
I put it back to default when the problem appeared.


If everything is set stock, I would suspect that the mainboard was bad.

BTW, is PC2100 the correct speed for the XP2500+ on this mainboard?

Well I can't say, but it's the only RAM I have, so ...

nForce2 should run with memory set synchronous to the CPU's FSB
rate for optimal performance (and sometimes stability too). I
have a Biostar M7NCG-400 (the IGP, integrated video mATX version
of your board) and in it's bios the setting for that is called
"Memory Frequency" (100%). If you're not running the most recent
bios update you might update the bios.

Your PC2100 memory is only spec'd (guaranteed) to work up to
133Mhz... it really isn't appropriate for your CPU. If all else
fails, you should get at least PC2700 (Might as well get PC3200
these days) since, even if the motherboard is unworkable, the CPU
still will dictate PC2700 memory or better to run the synchronous
FSB (or higher) that is meant for any motherboard.

Oddly my board (even when CAS3 memory is in it) is more stable at
CAS2.5 than CAS3... I believe it to be a bios bug so bear in mind
that some memory settings may need randomly changed and tested to
find a combination that works for your modules (IF they'll work
at all).

The following is a config I have for the board at the moment
(adjusted to be appropriate for your Barton), it has a couple of
junk memory modules in it prior to shipping them to someone.

System Performance [Expert]
CPU Ratio [Default]

FSB [166] (if all other attempts fail, a last resort is
lowering this FSB speed (or buying faster memory)).

CPU Interface [Aggressive] (try optimal later)
Memory Frequency [100%]
Memory Timings [Expert]
TRAS [11]
TRCD [4]
TRP [4]
CAS Latency [2.5] (try 3 later)
FSB Spread Spectrum [Disabled] (might be greyed out already)
AGP Spread Spectrum [Disabled] (Might be greyed out)
......
......
AGP 8X Support [Disabled]


- Then on another bios menu page: "Frequency/Voltage Control" -

DRAM Voltage Regulator [2.6] (try 2.7 later)



Now, before ever booting to windows you NEED to test after
any/every change with memtest86 v3.1a. Memtest86"+" is not
needed and IMHO, still has a few bugs so it should only be used
on systems that simply won't run Memtest86 non-+ version. Your
board will run the non-+ version fine, AFAIK.

It would also be good to make backups of anything that might be
corrupted by memory errors, but if system has been persistently
having errors then there might already be a lot of file
corruption and applications or whole OS needing reinstalled, but
regardless, making a backup of any valuable files/data is a very
good idea if possible.

Keep in mind that the short answer to your problem should've been
"don't use PC2100 memory, replace it".

kony wrote:
On Fri, 03 Sep 2004 03:17:26 GMT, anybody
wrote:


Noozer wrote:

"anybody" wrote in message
...


I have a Biostar M7NCD Pro (nforce2) motherboard as the basis of my
homebuilt. It has been running without a hardware problem for about 11
months.


The Biostar has three DDR slots, named B1, B2, and A1. To get dual
channel, you have to fill A1 and at least one of the B slots. I find
that there are Memtest-86 errors if and only if I configure the RAM as
dual channel.


What are the memory settings in the BIOS set at?


I guess you could say it's all stock. I don't understand much about
memory settings, so I didn't mess with it.

FSB: 166
Memory Frequency: By SPD
Resulting Frequency: 133
Memory Timings: Optimal
RAS-RCD-RP-CAS: 6-3-3-2.5

I have the choice Auto/By SPD for the Memory Frequency. I don't know
what is best for that.


Any overclocking involved?

I've had the CPU multiplier bumped up to 12.5 from the default (11, I
believe), and it ran fine and gave a nice little speedup all the while.
I put it back to default when the problem appeared.


If everything is set stock, I would suspect that the mainboard was bad.

BTW, is PC2100 the correct speed for the XP2500+ on this mainboard?

Well I can't say, but it's the only RAM I have, so ...


nForce2 should run with memory set synchronous to the CPU's FSB
rate for optimal performance (and sometimes stability too). I
have a Biostar M7NCG-400 (the IGP, integrated video mATX version
of your board) and in it's bios the setting for that is called
"Memory Frequency" (100%). If you're not running the most recent
bios update you might update the bios.

Your PC2100 memory is only spec'd (guaranteed) to work up to
133Mhz... it really isn't appropriate for your CPU. If all else
fails, you should get at least PC2700 (Might as well get PC3200
these days) since, even if the motherboard is unworkable, the CPU
still will dictate PC2700 memory or better to run the synchronous
FSB (or higher) that is meant for any motherboard.

Oddly my board (even when CAS3 memory is in it) is more stable at
CAS2.5 than CAS3... I believe it to be a bios bug so bear in mind
that some memory settings may need randomly changed and tested to
find a combination that works for your modules (IF they'll work
at all).

The following is a config I have for the board at the moment
(adjusted to be appropriate for your Barton), it has a couple of
junk memory modules in it prior to shipping them to someone.

System Performance [Expert]
CPU Ratio [Default]

FSB [166] (if all other attempts fail, a last resort is
lowering this FSB speed (or buying faster memory)).

CPU Interface [Aggressive] (try optimal later)
Memory Frequency [100%]
Memory Timings [Expert]
TRAS [11]
TRCD [4]
TRP [4]
CAS Latency [2.5] (try 3 later)
FSB Spread Spectrum [Disabled] (might be greyed out already)
AGP Spread Spectrum [Disabled] (Might be greyed out)
.....
.....
AGP 8X Support [Disabled]


- Then on another bios menu page: "Frequency/Voltage Control" -

DRAM Voltage Regulator [2.6] (try 2.7 later)



Now, before ever booting to windows you NEED to test after
any/every change with memtest86 v3.1a. Memtest86"+" is not
needed and IMHO, still has a few bugs so it should only be used
on systems that simply won't run Memtest86 non-+ version. Your
board will run the non-+ version fine, AFAIK.

It would also be good to make backups of anything that might be
corrupted by memory errors, but if system has been persistently
having errors then there might already be a lot of file
corruption and applications or whole OS needing reinstalled, but
regardless, making a backup of any valuable files/data is a very
good idea if possible.

Keep in mind that the short answer to your problem should've been
"don't use PC2100 memory, replace it".

Thanks for your reply.

1) What if I change the FSB Frequency to 133? I could live with the
slow-down if that would put the system back in spec.

2) Since the BIOS reports "Resulting Frequency" as 133, is the FSB
already running at 133 even though I have it set at 166?

3) Should I change that jumper JCLK3 mentioned mysteriously in the
"User's Manual"?

On Fri, 03 Sep 2004 04:51:29 GMT, anybody
wrote:


1) What if I change the FSB Frequency to 133? I could live with the
slow-down if that would put the system back in spec.

Yes, that would underclock the CPU but put memory back in spec.
It might still need some manually changed memory timings though,
remembering that mine has the odd bios bug about CAS speed.


2) Since the BIOS reports "Resulting Frequency" as 133, is the FSB
already running at 133 even though I have it set at 166?

True, supposedly it is @ 133, but these kinds of little issues
are why i try to avoid Biostar and some other low-end boards, it
just happened that I picked up mine dirt-cheap and wasn't in a
hurry to use it so I could afford some experimentation.

Point being, what should work in theory, may not work in practice
(as you've already seen).

3) Should I change that jumper JCLK3 mentioned mysteriously in the
"User's Manual"?


On my board, I have that jumper on the pins. IIRC, it sets the
default FSB to 100MHz, BUT, it is also overridden by the BIOS
setting. In other words, you can leave the jumper ON even when
running a CPU at 133, 166, 200, or anywhere inbetween. Some
people claim (some nForce2 boards, I forget if it applies to
these in particular or not) are more stable with the jumper on,
something about chipset timings that, once set at beginning of
POST, don't change again irregardless of the final FSB speed set
in the bios. I cannot confirm this, just repeating what I
vaguely remember.

If you already had the jumper on the pins, you could try taking
it off, but odds seem higher that leaving it on is the right
choice.

kony wrote:

Keep in mind that the short answer to your problem should've been
"don't use PC2100 memory, replace it".

I guess you are thinking that PC2100 would be a bottleneck, not that it
wouldn't work. Both crucial.com and kingston.com list a PC2100 part (as
well as PC2700 and PC3200 parts) as compatible with the Biostar M7NCD Pro.

It looks like somehow my FSB had been set to 166 by some accident. It
would seem to make sense to use PC2100 @ 133 but I still can't get it to
pass the Memtest-86 when set up as Dual Channel. After resetting the
CMOS, it does pass at 100 MHz though.

It is still under warranty, so I will send it back for replacement.

On Wed, 08 Sep 2004 07:41:19 GMT, anybody
wrote:

kony wrote:

Keep in mind that the short answer to your problem should've been
"don't use PC2100 memory, replace it".

I guess you are thinking that PC2100 would be a bottleneck, not that it
wouldn't work. Both crucial.com and kingston.com list a PC2100 part (as
well as PC2700 and PC3200 parts) as compatible with the Biostar M7NCD Pro.

It looks like somehow my FSB had been set to 166 by some accident. It
would seem to make sense to use PC2100 @ 133 but I still can't get it to
pass the Memtest-86 when set up as Dual Channel. After resetting the
CMOS, it does pass at 100 MHz though.

It is still under warranty, so I will send it back for replacement.

Your Barton does use 166MHz FSB, it was no accident, is
necessary to run chip at default speed, unless you have an
unlocked Barton and can change (it really DOES change) the
multiplier when the bios setting is changed.

nForce2 works best with FSB & Mem bus at synchronous
settings, therefore having the 166MHz FSB CPU, means it
should be paired with PC2700 memory. Since there is a bios
setting to run memory lower than FSB (IIRC), you could try
that, but it may not be stable, and is certainly lower
performance... it is not meant to run in that configuration
for best results.

If it won't pass memtest86, there are options I often
mention, retest at different memory bus speed, or increase
memory timings... either way, you'll just have to settle for
whatever works for you, but it would still be better to get
different memory, preferribly PC3200 instead of PC2700,
since it has even more of a margin.

You could send your PC2100 memory in for replacement, but a
module might be compliant with PC2100 spec and still not
work on that particular board, with that particular
asynchronous memory bus speed. Then again, most PC2100
memory sold these days is artifically downgraded PC2700 or
3200 chips, so if replacement is a newer lot of chips it may
indeed work better, for the wrong reasons but I suppose it's
all that counts in the end.

kony wrote:

It is still under warranty, so I will send it back for replacement.

You could send your PC2100 memory in for replacement, but a

I mean I am planning to have the mobo replaced, since the system passes
Memtest-86 when any RAM is installed in one bank only and fails when RAM
is installed in both banks (ie Dual Channel). So I think the RAM is okay.

themattfella