Z68XP-UD4, 4 memory slots full = Windows problems

[thepretender]

Z68XP-UD4, Intell I5 2500K, Patriot Signature 4 gig sticks PSD38G1600KH.
Computer runs fine with 2 sticks of memory = 8gigs but with all 4 slots full 16 gigs, I get various memory problems in Windows 7 x64 eventually leading to corrupt files.

Memory set in bios to Auto, running at spec voltage 1.5, I ran Memtest with all 4 sticks installed and tested fine after 5 hours and Windows  runs fine with either pair installed. Also tried setting memory to spec timings 9-9-9-24

Do I need to manually set the memory to slower timings if so what settings?

[Aussie Allan]

 No....What you need to do is test the memory individually in slot one (applicable to your board)..... 10 passes each with Memtest.....this is the industry recognized standard  to establish a module (or set) of memory is actually trouble free.

  The reason it's done this way is ....although hard to explain, or even understand for that matter, ...memory tested together/concurrently will give false POSITIVE readings even if there's faulty modules present........Sure it's seems faster......but a total waste of time and electricity.

  3 times out of 5........memory is behind actual hardware problems........if not........at least you can emphatically rule out the memory in the fault finding.

  Aussie Allan

[thepretender]

In the end the Patriot memory just isn't compatible with UD4 and I5 at least with 4 sticks, 2 sticks 8gb works fine but 16gb just ain't stable.  I tried everything more volts both cpu and memory, 1333 instead of 1600 lower timings with more volts. Got close but couldn't get stable. Took memory back and got Corsair Vengeance 1600 4 sticks of 4gb  and was stable at 1600 right out of the box.

[Dark Mantis]

Yes sometimes that is how it goes and I always like to check first to make sure that the memory is compatible.  The Corsair Vengeance is great memory for the price though. I just bought 16GB for £93.00, excellent value for good RAM.

[zeneffect]

Ive had problems using 4 sticks of PSC, BDBG, and Hyper.  This issue does not appear to be Gigabyte specific either.  When all 4 slots are occupied on any Giga or Asus board I have, I get a reboot loop or massive instability.

FIX:

The reference and control voltages are set by a ratio of 1/2 the DIMM voltage.  To get all 4 working, the ratio is NOT optimal and needs to be set to .49.

So, on Gigabyte, (using the Z68XP-UD4) I set volgate to 1.72 dimm, 0.850 for the 4 reference voltages which are the last 4 that say .750 next to them.  this resolved my instability and boot issue.  NOW if you want to use 1.65v or whatever voltage you want, follow the 1.72v instructions then modify the dram voltage.  The bios retains the ratio you set so its all good from there.  Hope this helps you, it certainly helped me (and i didnt get any help from anybody to come to this solution so it took like 2 weeks to figure it out)

[Dark Mantis]

Hi

Yes this is a fairly standard fix for filling all the memory banks at once and it is noit often that you can get away without it. What you MUST do though is to make sure that your QPI/Vtt is no more than 0.5v less than the DRAM voltage or you will likely damage the memory controller and now that is on the CPU that is a new processor if that happens.