Changed motherboard, 6GB ram doesn't work.

[Samase]

Hello.
I've changed the motherboard from Gigabyte P35-DS3 to Gigabyte EP45-UD3LR.
My RAM: Corsair Dominator PC8500 2 X 2 GB + 2 x 1 GB
Before I changed the motherboard i checked if my current ram memory is supported by the motherboard, and they do. I am also using the correct settings.
Everything seems to work correctly except that I do not get any display on my screen if I use 6GB Ram.
I do get display when I only use 2GB or 4GB.
Thus, individual sticks in dual-channel, but not four sticks simultaneously.
My previous motherboard (Gigabyte P35-DS3) managed 6GB RAM splendidly.
I have also updated the BIOS to the latest version and that didn't help.

Does anyone know why i can't get any display with 6GB?

CPU: Intel Quad Core Q6600
Motherboard: Gigabyte EP45-UD3LR
Ram: Corsair Dominator PC8500 2 X 2 GB + 2 x 1 GB
PSU: Corsair 550w

 

[bilbat]

Always a bad idea to mismatch modules on a motherboard - simply asking for trouble. To try to get them working:
Put one pair, either the 2Gs or the 1Gs in, do a "Load Optimized Defaults" from the BIOS, save and restart; go into the BIOS, and on the "MB Intelligent Tweaker(M.I.T.)" page, note and write down your memory timings - all of them. Shut down. change ot the other pair of DIMMs and repeat - do "LoadOptimized Defaults", save exit and reboot, go into the BIOS, and on the "MB Intelligent Tweaker(M.I.T.)" page, again note and write down your memory timings - all of them. Compare the two sets of timings. Whichever pair result in the highest numbers - put that pair back in, by themselves, and do it again - "LOad Optimized", save exit, and reboot. This time, go into the "MB Intelligent Tweaker(M.I.T.)" page, check that your "DDR2 OverVoltage Control" is set to "+0.3V"; set your "(G)MCH OverVoltage Control" to "+0.1". Save, exit, and power down. Your memory must be inserted correctly: put the two gig pair in DDRII_1 and DDRII_3; put the one gig pair in DDRII_2 and DDRII_4. Power up and see what you get...

Good luck - you'll be needing it!

 

[Samase]

I did as you told me with no success. Is there any other way to boot with 6GB of ram? I booted 6GB ram just fine with my last motherboard, P35-DS3. I don't see any reason i can not boot with 6GB with my current motherboard EP45-UD3LR. Although, i replaced the 2 x 2GB ram the same time i replaced the motherboard. I can now see that there is different versions of the ram. The 2 x 1GB has version 2.1 and the 2 x 2GB has version 1.2. Does those versions do any matter?

Thanks

 

[bilbat]

When you wrote down the memory timing numbers, were:
they the same?
one set consistently higher in any numbers that differed?
there some numbers interspersed in the one that was overall lower, that were higher than individual numbers in the one that was overall higher?

Wouldn't hurt to post the two sets of numbers, verbatim...

Here's my point: I'm thinking that, first of all, the northbridge (MCH, or memory controller hub) on your old board may have been more 'tolerant' of odder memory timings, and second, that you 'got lucky', and the memory that you had in the board first, and for which the board set itself up, was slower ('looser' timings - higher numbers) than the set that was added - therefore, the board's timings were overall slow enough to tolerate the different sized DIMMs. Trust me though - you did 'get lucky', this is neither a common situation, nor one that the harware is really built to accomodate - for best performance and reliability, you alway want 'matched' memory modules...

 

[Samase]

I loaded first the 2GB pair and did "Load Optimized Defaults" and then wrote down the timings, did the same with the 1GB pair.

They were exactly the same, i even tried to lower the timings to try to get the computer to boot properly but that didn't work.

 

[Samase]

I mean of course to get the timings higher, and NOT lower.
My bad.

 

[bilbat]

Hmmm... It seems really unlikely that the timing numbers would be identical, but if they are, that'a a very good thing! Am I correct in assuming that the machine will boot on either pair of the sticks, just not with them all together? I ask, as we may get to the point where I'd like you to run a program to read the on-DIMM registers directly for their timings...

For now, if you'd post the actual RAM part numbers, there are some other BIOS numbers I'd like you to check out..