Memory Unstable, 4 sticks with Gigabyte AM3+ Motherboard

[twarnold]

Motherboard: Gigabyte GA-970A-D3
CPU: AMD FX4100
RAM: G.Skill F3-12800CL9D-8GBSR x2 (4x4GB sticks)

Computer is not recognizing all of the memory. Windows (fresh install in Windows 7 Pro) says it sees 14GB with 12GB usable.

BIOS says it sees 12GB. It briefly said that it saw all 16GB.

I've contacted Gigabyte tech support, got the most updated BIOS (F8D), tried setting the DRAM voltage manually to 1.5v. None of that changed anything. I followed the directions here (http://gskill.us/forum/showthread.php?t=7688) and set the CPU-NB freq and voltage, and the timing settings appropriately. I briefly had all 16gb recognized and then system became unstable and I started getting lots of BSoDs. For the time being, I am back to the Fail-Safe defaults for the BIOS.

I've also tested each stick individually and they seem to all be working fine. Problem seems to arise when all 4 are in at once

Please let me know if I need to post any more info about my setup. Thanks for the help!

[Tradesman]

With two sets may want to raise DRAM voltage to 1.55 to 1.6 also may need to raise CPU/NB voltage about + .05 to give the MC a boost for 4 sticks.

[twarnold]

Still no change

Ok. Loaded Optimized Defaults in BIOs, then set DRAM Voltage to 1.6V and set CPU/NB Voltage to 1.11V (up from 1.105V). Memory Clock is by default 1600Mhz. Still not seeing all the memory unfortunately. And Windows seems to be running pretty slow.

Could it be a timing issue? My timing settings are all set to default right now:

CAS Latency - 11T
RAS to CAS R/W Delay - 11T
Row Precharge Time - 11T
Minimum RAS Active Time - 28T
TwTr Command Delay - 6T
Trfc0 for DIMM1 and DIMM3 - 160ns
Trfc1 for DIMM2 and DIMM4 - 160ns
Write Recovery Time - 12T
Precharge Time - 6T
Row Cycle Time - 39T
RAS to RAS Delay - 5T

I'm new at customizing BIOs, so if there are any other settings that I need to double check, please let me know.

Thanks!

[Tradesman]

Try CPU/NB @ 1.15 to 1.2

[twarnold]

My Mistake

Ok, so I feel like a fool. I thought I had gone through and tested all the sticks individually, but maybe I missed one when I first got them. Or maybe it was just unstable and it worked the first time I tested but no longer.

I went through and retested all the sticks in slot 1 just to be sure, and it turns out one of them is defective. Won't boot when its by itself. When I pair it with another one, it SAYS it is recognizing 2 of the 4GB that should be there. But my guess is that is just a glitch.

So I will RMA that pair and try again when I get the replacement set.

Thank you for your help!

With just the 2 sticks in the meantime, should the BIOs defaults be sufficient?

[Tradesman]

As long as it's stable