DDR3 help

[Canaie]

I was running 3x2gb RAM and wanted to upgrade. So I though that I would get 2x4gb, discard one of the old dimm's, and run the new and the old ones in dual channel for a total of 12Gb. The trouble is that I can't get the motherboard to boot with this configuration. There's a little LED on the motherboard for diagnostic codes, and F3 comes up which is not in the manual but seems to be dimm related. I can run the new 2x4gb just fine by themselves.

Mobo: http://www.newegg.com/Product/Product.a ... 6813188046
Current Ram: http://www.newegg.com/Product/Product.a ... 6820226030
New: http://www.newegg.com/Product/Product.a ... 6820226178

[Greebo]

In what order are you putting the ram on the board?

[Canaie]

Page 20 of the manual for reference: http://www.evga.com/support/manuals/fil ... l-e758.pdf

I'm usling slots 2,1,4,3 so filling up the top 4. I'm going 3gb, 4gb, 3gb, 4gb. I also tried 3gb, 3gb, 4gb, 4gb but with no luck.

[Greebo]

Try 4,4,2,2. You'll definitely want the pairs to go in 2,1 and 4,3

[Canaie]

Still no luck.

[Frygyd]

From the top down try ...

4, 2, 4, 2 and put your extra 2 in the very bottom slot should work.

[Canaie]

That still didn't work. Going to check if there's a newer firmware for the motherboard.

[Grainger]

Yeah, not going to work in dual channel mode. It should work non-dual channel but I wouldn't rely on it. Consumer/Desktop Mobo's just aren't clever enough to handle mixed memory sizes on dual channel. There will be a compromise somewhere in the design of the board or the bios. (No way that board is full NUMA spec) Even if it would work your memory will have to be clocked down to the slowest chip. You might get it to work as 4x2Gb if you can configure that in the bios, but that's wasting the extra memory on the 4gb sticks.

Memory is so cheap now just buy another 8Gb and use the old memory in another machine.

[Canaie]

I got 4,4,2,2 to work with the latest BIOS. Seems I had the initial version from 2008 and EVGA kept updating through 2011.