Memory reported at post screen as 6GB then 12GB now 4GB..always random !

Hi all

 

I bought a PC end of last year from PowerC computing in the UK. As I started to use the machine I would notice that the memory was being reported incorrectly at boot up.

 

The machine has 12 GB of ram, I just pulled out the memory to register on this forum and its called Corsair XMS3 CMX6GX3M3A1600C9 1600Mhz (3x2GB) 9-9-9-24 1.65v ver 2.3

 

My Bios never reports the ram correctly, sometimes it says I have 4GB, other reboots it shows the full 12GB but it seems completely random and has shown 8GB, 6GB etc.

 

I sent the PC back to PowerC and they said they replaced the motherboard and the ram and sent me the machine back after a week. I got the machine back and there is no change?? the ram is still reported incorrectly on different boot ups.

 

I have a Gigabyte GA-EX58-UD5 motherboard with the F12 Bios.

 

Do any of your experts please have a solution?

 

Many thanks for any help as this is very frustrating and the company I bought it from don't seem to know what's causing the problem.

 

Thanks

Anim

CMD12GX3M6A1600C8 or HX3X12G1600C9 would have been the proper 12Gb kit to use, not 2 6 gig kits.

mixing kits that were not tested as a single kit at the factory is always a crapshoot and usually requires lowering the frequency and raising voltages.

they should have known better.

its difficult for Corsair to support a mixed set as they were not intended to be installed like that.

Ahhh dammit, ok, so I basically need to get back in touch with the dealer and repeat what you said?

 

Or would they be in their right to tell me to lower the frequency and raise the voltage as a solution?

 

Thanks again for the fast response.

 

Anim

you paid for 12Gb of working reliable DDR 1600 so any reputable dealer should take whatever steps to ensure customer satisfaction.

the proper kit runs roughly 4-500$ US

you may want to look in the bios to see if XMP is enabled. it should be.

Interesting you mention XMP.

 

I just looked at upping the DRAM voltage but noticed XMP was not enabled. I just enabled it and the ram is now at last being reported at the 1600 speed with a 1.65v setting.

 

After a reboot it found 8GB (which is correct as I have removed 2 sticks) so will see how stable this runs.

 

Thanks.

 

Anim

well thats good news! i'd pop in the other 2 and see if the extra voltage/modified settings will help all 6 stick play nice in the sandbox :)

good luck!!

About to try it now.....

Unfortunately it didn't work.

 

It would only see 8GB even when I rebooted several times it would not see the extra 2 x 2GB sticks i put back in.

 

I then shifted all the sticks along a row so rather that the 2 banks near the CPU being free the other end was free, this still reported 8GB which suggests that the mb slots are working ok.

 

It just will not detect the ram with all slots filled and caps at 8GB.

 

Ah well

 

Thanks

Anim

Forgot to mention, If I added one stick back in (for 10GB) the bios screen said I had 4GB installed ! Took that stick out and it said I had 8GB, add all sticks and it still said 8GB.

well that brings me back to the point that the dealer should have installed a pretested 12gb kit instead of 2x6s.

 

hopefully they can make good on a 12gb kit. i'd give them a call.

you can point them to these forums as a reference to use a full kit instead of mixing sets.

I can't really afford to send the machine back to them a second time so hopefully they will do a ram exchange instead. I have just emailed them.

 

Cheers for your help.

Well it doesn't look too good, here is their reply.

 

Thank you for your email.

What I will have to do is look into this further.

Because we have sold allot of these PC’s with the same specification without any problems.

I don’t think the answer is actually swapping it out with a 12gb kit.

I will let you know what will be the best action to take.

 

I guess I have to wait and see.

im sorry you are getting a hard time, its been made clear here a thousand times that mixing kits is not recommended or suggested. that is the official Corsair stance on this.

ill bet i can fine a hundred quotes from Ram Guy stating this.

 

by them stating that "I don’t think the answer is actually swapping it out with a 12gb kit." tells me they have not done any research themselves and i wonder how many other computers they have built and not enabled XMP to reach the full capabilities of the Corsair products they sell.

 

if i were in your shoes i would not drop this, you paid a premium im sure for your PC and should get what you paid for.

 

maybe a call to Corsair customer service can help you reach a resolution? i'd be curious as to what their suggestions how to proceed from here. in the US we have the Better Business Bureau to act on behalf of the consumer regarding disputes, im not sure what services are available to you across the great pond.

 

please post back any developments if you don't mind.

I ran memtest with all 12GB in, bios actually spotted all the ram too.

 

Start of memtest:

 

http://www.geoffcoope.co.uk/img/IMG_0390.JPG

 

After 2 hours running:

 

http://www.geoffcoope.co.uk/img/IMG_0394.JPG

 

I take it this is more proof that the ram is at fault?

 

Thanks

Anim

i know its a pain but you need to test 1 stick at a time to find the faulty one.

 

- I'm getting errors in test #5 and/or #8 and have read a lot about it.

Yes there are just about enough discussions on the topic to fill a book, but it all boils down to the answer given above. The only thing that can be said is that many times, when memory latencies are incorrectly set in the BIOS you will experience errors in test #5 and #8. (Though #8 does not exist anymore as of version 1.40 and might be reinstated as a different test in a later version.) This does however NOT mean that errors in these tests are always the cause of incorrect settings; your memory might just as well be defective. However, if you have a failing module they will usually fail in test 4 no matter what frequency you run them at or at any given clock setting. And failures in test 5 or 8 usually would suggest that either one of a few things:

 

A. The settings are too tight or to aggressive for your system, IE not every MB can run with Cass timings of Cass 2-2-2-5 at DDR400 like with our XMS3200XL modules, and maybe relaxing the timings to check for this would be prudent to test. Try Cass 2-3-2-5 with the Rass to Cass set to “3” for example

 

B. You may have an un-stable power supply for your system configuration. Make sure that you have the correct type of PSU (Power Supply Unit) and that it has enough power for your system configuration.

 

C. You may want to look your specific modules part# up in XMS Qualifications and Testing (http://www.asktheramguy.com/forums/s...ad.php?t=52351) to see if there are any voltage and/or MB requirements. Like adding extra cooling.

 

D. One of your modules may be failing, but that would or should become apparent when testing then individually.

1 stick at a time, makes sense now you said it. Ok. Will be testing them all tomorrow and see how I get on.

 

Cheers

Test results:

 

All 6 x 2GB Sticks used = Boots fine but fails on test #5

Each individual stick in 1st white slot for 1 pass = OK

3 sticks used in blue slots = Fails, just restarts constantly.

3 sticks in white slots for 1 pass = OK

 

Is it normal for the blue slots to fail if only those ones are populated?

 

Does this help?

your board may require ram in the white slots before using the blue ones.

please check your user guide to confirm.

Some more testing and positive results

 

1. Disabled XMP Memory Profile

2. Increased DRAM voltage to 1.64 (there is no 1.65 as the next one up is 1.66)

3. Lowered the Memory clock speed using the lowest multiplier which is 6 this set it too 1153 (This machine has cooling specifically for overclocking, the CPU is now set at 3.8Mhz using a BCLK of 190) - I know I shouldn't OC the CPU until sorting out the ram issue but if this proves unstable its the first thing I will drop back to stock.

 

Ran Memtest 15 mins and it went through test #5 OK

 

I am obviously here in Windows and will try it like this for awhile and see how stable things are.

 

EDIT: Forgot to mention that all 12GB is showing up in POST.

EDIT2: Also forgot to say the BIOS wants to set memory timings at 8-8-8-20 which I have overridden and set it to 9-9-9-24

 

Thanks

Anim