Asus x79 Sabertooth - Memory(?) Issue

[haelthhazad]

Hi all,

I have posted on other forums about this but figure spread the net wide and somebody might have new advice.

I have an Asus x79 Sabertooth mobo, 3930k CPU and a quad channel kit of Corsair Dominator RAM which should run at 1600Mhz.

The problem I experience is at boot the DRAM LED lights up, the system fails to POST and we get a nice black screen to look at.

So... I use the MemOK! button on the board which reboots the system and 'does its thing' dropping the RAM speed and timings to something low. I then get asked to save the new settings in the BIOS and the system will then boot.

I can restart the system and everything is ok but once I shut down I have to go through the above process all over again. The RAM speeds that the MemOK sets are not the same each time but can vary wildly.

I have the latest BIOS etc and for some people this apparently fixed this issue - I flashed the BIOS again in case it was lying when it said it was the latest version

THe system did seem to work after that in that it booted with the right settings - I shut it down and started and it 'just worked' - wahey! But... The next day same old same.

I have taken the RAM and put into another machine and it boots fine but unfortunately the mobo in that machine will only run memory at 1333 I think it is so I can't test the RAM at 1600. This however does lead me to think the RAM may be OK.

I have submitted cases to the various supplies and am awaiting responses (or in some cases useful responses).

Within the BIOS I have tried setting the 'AI Tune' to auto/XMP and manual.

The BIOS reads the XMP profile of the memory and applies it correctly. The menu option for the DRAM lists each module as 'OK' and lists all of the SPD info from them.

So far it has been suggested it is either the mobo/cpu or RAM which sucks when its all such high end kit.

I apologise for the length of the post, I wanted to be concise. I would be grateful of any suggestions and if I have missed anything please let me know.

[bigdaz84]

I take it you've tried booting with just one stick of ram or just one pair to see if any of them is faulty?

Have you tired manually setting the ram timings and voltage when you do get the system to post?

[8 Pack]

What I would do is remove all components appart from the essentials to Boot. So just CPU, Graphics and Power plus one stick of RAM inserted in to one of the furthest slots from the CPU does not matter which side and try boot the board. Set the timings manually including VCCSA at 1.25 (To make sure this setting is OK) and the correct DRAM voltages. Save, Reboot and Test each stick of RAM in turn using memtest USB stick version.