Differential diagnosis: it's memory fault or motherboard buggy?

[twistedbrain]

Hi!

I've the following nasty problem: a PC with a motherboard Gateway
GA-G31M-ESL2 rev 1, F8 with 2 slot for memory and 2 DIMMS Corsair
TWIN2X 4096-6400C4DHX (2 GB each). I tried many time to install
different Linux flavours, Kubuntu and OpenSuse, but after some tens
minuts the process freezes and the PC too, I have to push the power
button to restart it. The memory should be fit for the mobo because
Corsair on its website says so, also if the Corsair one could work with
CAS 4-4-4-12 and at 2,1 V, instead the requirements for the DIMMs for
such mobo are CAS 5-5-5-18 1,8 V.

I launched memtest 4.0 that you can find with OpenSuse and after few
minutes it reported some thousands errors in test3 (Moving inversion 8
bit pattern) starting about from 1800 MB where the pattern dfdfdfdf
become dfdfdfdb (errbit 4). But If I test each memory stick in each
memory slot I don't get errors. There are errors only when the memories
work together in dual channell.
Now either mb, either RAM are new and I've the right to the warranty,
but which one is the broken one and why? (I don't have other mb or other
DIMMs to check).

Best regards to all and thanks to replying people,

Andrea

 

[twistedbrain]

kony ha scritto:

Had the system previously been working properly and if so,
what has changed since then?

Never. It's new, assembled since few hours.

Check temperatures and voltages, in the bios health/hardware
monitor screen if it has one. If you have a multimeter also
check PSU output voltage.

The temperature is low, either from BIOS sensors (about 28-30 C
the CPU), either from my fingers (at PC switched off since few
seconds).

It might help to link to their compatibility listing for the
memory on the website.
http://www.corsair.com/configurator/product_results.aspx?id=754044


Does the motherboard have bios settings for memory timings
and voltage? Can you determine if the board is running the
memory at 4-4-4-12 or at 5-5-5-18? Often an issue with
high spec memory that needs more voltage is OEM boards may
not have settings for that.

That's true for CAS latency, it is they aren't tunable in BIOS, but the
voltage is tunable. It is the memtest see always 5-5-5-18, but I could
understand errors if the mobo setting have had been 4-4-4-12 and the
memory ones 5-5-5-18, in this case, adjusting the vattage of the mobo to
2.1, they should work correctly also because Corsair in that web page
says so. I've found memtest errors either with 2.1 V, either with
1.8 V, either with 800 Mhz, either with 667. I've also upgraded the mobo
BIOS to the last version, but memtest errors grew (also in test 4 and 5,
not only in 3).

I suspect the motherboard is simply incompatible. You might
check to see if there is a newer bios that might improve
memory compatibility, in addition to what was mentioned
above, see if the bios offers memory settings to raise the
timings or the voltage, or for a quick test you might
temporarily try raising both.

What I did. Maybe you're right, but in such case Corsair is not.

I presume when you checked each module individually you
tried them in both slots to rule out the possibility of one
of the slots being bad.

I did like that.

If it is just incompatible, it depends on what you value
more. It would be quicker and easier to just pull the
memory and mail it in and get something with 5-5-5 timings
and 1.8V rated.

I asked for that, but I suspect also that such memory is really
broken if that Corsair web page is right.
A bit strange thing is that such motherboard don't give 1.8V,
it gives 1.92V at minimum and I read that is not only my mobo, but
all the GA-G31M-ESL2 rev.1.

It might be higher performance to instead
keep the memory and get a different motherboard more capable
of running it, but such a board might also cost more and
then there is the time to pull it from the case and install
the new one, collect drivers if you dont' have them, etc.

The problem could be that I wont a motherboard with Intel G31 chipset
because it has low consumption, either per se, either because it has
graphics integrated (Intel GMA 3100), either because it can run
processor, like my Duo Core 2 E7500 at low consumption. Then it costs
also few bucks, so I doubt that I can find a mobo of such type that can
operate without trouble such DIMMS.

Thanks and regards,

Andrea