GA-X58A-UD3R Triple channel RAM problem

[hibrow]

Hi there everybody - this is my first post here.

I have had a BIG problem arise with my 3 x 2Gb Corsair XMS3 RAM in my GA-X58a-UD3R Mobo with i7 930 CPU. I built the system in october last year and everything has been running fine and stable...until today!

I had noticed that in the POST screen the RAM was not reporting the 1600Mhz as spec'd and came accross a forum discussing X.M.P. Long story short - I enabled XMP in the BIOS and the settings all looked good to me v 1.65, 1600Mhz, 9-9-9-24 etc. (exactly what it says on my RAM modules.)

When I rebooted, Windows loaded correctly but I immediately noticed that only 2Gb of RAM was registering. Panic!

The motherboard is now only recognising the module in Dimm slot DDR3_3. Confusingly the Memory Tab in CPUZ is reading that the Memory size is 4096Mb and the SPD Tab shows Memory modules present in Slot #1 & 2 but not in 3,4,5 or 6.

I have tried resetting everything using the Clear CMOS button. Loaded optimised config in BIOS and tried running Memtest86 which reported no problems with the 2Gb that it could see. ( I have now tried this with all three sticks of RAM - they're all OK)

I have physically removed the memory sticks and checked each on their own. All of the sticks are running fine when they are placed in Dimm slot 3 (White one in the middle) and the PC will boot properly when all 3 are in place (in white slots) It just doesn't recognise more than 2Gb. POST shows only 2Gb also - albeit at 1600Mhz now.

No other slot on the Motherboard will recognise the sticks at all and the machine will not boot if only a single stick is in any other slot than DDR3_3, it doesn't BEEP (the speaker is workingm it beeps on sucessful post) and it doesn't even show a POST screen. Just a black Screen, Fans spinning, Drives Spinning, a few LEDS on the board light up Blue & Green but nothing else will happen.

I would really appreciate any suggestions or links to other similar problems. I've read a lot of forum threads now and haven't managed to find anything close to this problem.

I'm starting to think this is an RMA situation? I really hope not!

Kind Regards,
Tim

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

It is quite poossibly just a matter of the settings.

I think your memory is default at 1.65v, if that is correct try increasing it to 1.66v

The Qpi/Vtt needs to be somewhere between 1.2 and 1.4v and will have to be played aropund with to find the optimum setting.

Change the timing to 9-9-9-27

As I say try different voltages for the QPI/Vtt

[hibrow]

Cheers for getting back to me so soon.

I've had a go at the settings you suggested but no luck. The BIOS still does not recognise the modules in DIMM DDR3_1 or 5. It just shows - marks where the data should be. I'm concerned that the memory didn't "re-appear" when I set all memory settings back to their defaults.

Do you have any other suggestions?

Also - it says in the mbo manual "When enabling 3 channel mode with three, four or six modules it is recommended...."
How do you enable the Triple Chanel mode? is there a setting within the BIOS or does it just enable automatically? As it did on its first boot I assume.

Thanks again

[Dark Mantis]

Triple channel mode is done automatically by inserting the right number and sequence of modules.

There are two normal reasons for not seeing the memroy. One is the settings as I explained and the other is bent or burnt pins. As you don't seem to be getting anywhere with the settings maybe it would be worth checking the pins on the CPU socket. I didn't suggest this at first as yoiu have been running alright for so long but I think that now it might be worth it.


Very carefully remove the heatsink and fan. Probably a slight twisting motion is best to release the two as the thermal paste can act like a glue.

Once off remove the CPU taking extreme care both physically and electrically(static) and place somewhere safe.

Make sure that the lighting is very good and even.

Now scrutinise the socket for any pins that are out of alignment, even slightly.
If in any doubt whatsoever take a couple of macro (close up) photos of the socket and post them on here for us to check.

Also look at the bottom of the CPU at the lands (little copper circles) and make sure that there is a mark in each somewhere near the centre.
If there are any missing marks or any of the pins are obviously bent then that is your problem.

Before refitting the CPU clean off all residue of the old thermal paste and the same on the heatsink and then apply a small amount (about the size of a grain of rice) to the centre of the CPU once it is inserted in the socket.

[hibrow]

Had a look at the CPU today and there were several lands with no marks on at all. I had a close look at the socket with a magnifying glass but couldn't see any obviously bent pins.

I've now refit the cpu and voila, 6Gb! It's Back!

Question now is how this has happened and will it likley cause problems in the furture?

Can't thank you enough for the advice, you're a star.

[Dark Mantis]

Well very glad I could help. The problem might just have been that the CPU wasn't quite located properly in the socket and that is why the pins didn't contact the lands. The only other reason would be if the pins were not bent but not level in height and so some were not making contact properly.