GA-X58-UD3R R2 w/ G.Skill CL6-8-6-20 F3-12800CL6T-6GBPI

[ash88]

Greetings.

I have a GA-X58-UD3R Rev. 2 mobo and 12 GB (6 Sticks) of G.Skill CL6-8-6-20 F3-12800CL6T-6GBPI Ram.  I am having no end of memory problems and would appreciate any help to get this up and running stable.

I have manually set the memory timings (6-8-6-20) and voltage (1.6v) in the bios.

When I have all 6 sticks of ram in only 4 of them are seen - in the "Status" screen of the cmos it shows that 2 of the sticks aren't available.

When I use (any combination) of 3 sticks all of the memory works, however the system freezes (both in the bios, and in the operating system windows 7.0) intermittently.

I have tested all 6 sticks of memory individually with Memtest86, and all have passed at least 3 passes of the scan.

My assumption is that since this ram runs at CL6 and I have 6 sticks of it I might need to tweak some other settings in the Bios - but I have no idea (aside from setting the memory timing s and voltages as per the memory specs) what to start tweaking.

Any help is appreciated!

[Dark Mantis]

Hi and welcome to the Gigabyte Forum.

The problem you are having is because of the extra loading you are putting on the memory controller by filling all the slots. You will need to increase the memory voltage a little ( depending on your memory settings) if you post them here we can probably help you.

You will also need to paly around with your Uncore and QPI/Vtt settings.

Post all your memory details here and we will try and give you some guidance.

[ash88]

Thanks Dark Mantis!

Here are my current memory settings:

XMP: Profile1  (manually set)
System Memory Multiplier (SPD): Default
Performance Enhance: Standard  (manually set)

CAS Latency: 6  (manually set)
tRCD: 8  (manually set)
tRP: 6  (manually set)
tRAS: 10  (manually set)
DDR Voltage: 1.6 (manually set)

QPI/Vtt: 1.175 (auto)

If I missed something just tell me what I need and I will post it.

Thanks again!  This system freezing all the time is killing me.

[Dark Mantis]

Hi

tRAS: 10  (manually set)

If that is correct and not a typo then I am not surprised you ar ehaving problems. Should read at least 20.

What memory multiplier are you running?

What is your Uncore set to ?

If spec voltage is 1.5, set 1.55 or so.   If spec voltage is 1.65V set it to 1.66v or 1.68v

Make sure that your QPI/Vtt keeps within 0.5v of the memory voltage. It can be closer but no further away. This is a figure that you will probably have to play with to get stable but you may need 1.2-1.45+ QPI/Vtt

[ash88]

Memory Multiplier: 8x (more on this below)
Uncore Multiplier: 16x

I changed the Uncore to 1.68 (from 1.65 as per spec) and the QPI/Vtt to 1.95 (to keep it within 0.5 of the Uncore).  I will see how stable the system is over the next while.

I did notice that somewhere along the line my Memory multiplier got set to 8x.  I believe that with this PC1600 ram I should be setting my Memory multiplier to 12x.  However, when I attempted to do that the system failed to boot and indicated an overclocking error.  Setting the Memory Multiplier back to 8x allowed the system to boot.  Should I be tweaking something in order to get the full PC1600 off the ram?

I really appreciate your help!

Cheers.

[Dark Mantis]

Don't forget that if you change your memory multiplier to 12x you will also need to change your Uncore to 24x - 26x at the same time. If you increasde the speed of the memory you will have to increase the voltage a touch too.

[ash88]

Hey Dark Mantis,

I haven't made any new changes wanting to get a good sense of system stability.  The system is definitely more stable - however it still freezes occasionally.  Roughly every 3 days, rather than every day (or more).

I'm going start tinkering again.  How high is too high for the voltage settings?  Is there a rule-of-thumb on voltage settings?  Afterall, I'm assuming that the memory is the hardware that is causing the freezing, but it could also be the Motherboard or CPU.  So at what point can I rule out "not enough voltage" as the problem?

Thanks!

[Dark Mantis]

Generally if the default voltage is 1.65v for the memory then you can go as high as 1.72v as you are running 12 GB but dont forget QPI/Vtt voltage must be kept within 0.5v of the ram voltage.