Asus M4AATD-M/USB3 with 12800CL9D-4GBNQ

[nhry]

Hi, I've got a strange issue with my current setup.
Motherboard: Asus M4A88TD-M/USB3
Processor: AMD Athlon II X4 635 2.9GHz
Memory: 12800CL9D-4GBNQ (2 sets, 8 GB total)
OS: Windows 7 64 bit

When I run my computer with 4GB of RAM, (I've tried every possible mix of sticks and DIMM configurations) everything works fine. But when I install 8GB of RAM I get BSODs for up to an hour after startup and restarts, but everything works fine after that. I can restart as often as I like after that and I have no issues either, but when the system is powered down for a few hours I get the same issues again. (This issue occurs with 6GB of RAM as well)

I run my memory at 1333 with timings of 8-8-8-24 at 1.5V.
I've tried CPU/NB offsets of 0.1, 0.125, 0.15, 0.175 and 0.2.

Any idea why I can't seem to increase my memory beyond 4GB without everything screwing up?

[nhry]

Oh I forgot to mention that 8GB of RAM shows no errors in memtest86+ for up to 8 passes (took about a day)

[Tradesman]

Your MC (memory controller) may not have enough juice, (need voltage to CPU/MC and HT) and to run your DRAM at the higher speed will probably require require an OC to push the 8GB, if it can run it. If no luck, might post your BIOS settings to see if we can find anything in particular

[nhry]

Okay, I ran it this morning and it crashed in 20 minutes, better but still not good. Here are my Bios Settings

CPU Offset Voltage: Auto (1.35)
CPU/NB Offset Voltage: + 0.1
CPU VDDA Voltage: 2.5
DRAM Voltage: Auto (1.5)
HT Voltage: 1.3
NB Voltage: 1.3
NB 1.8V Voltage: Auto (1.8)
SB Voltage: Auto (1.1)

CL: 8
tRCD: 8
tRP: 8
tRAS: 24
CMD: Auto (2T)

[Tradesman]

Might try CPU/NB up another notch, also what's your tRFC at, may need to raise it a level also w/ the 8GB

[nhry]

Okay, I brought up the CPU/NB voltage to +0.15V. My tRFC was at 110ns and I raised it to 160ns, is there a timing that is recommended?

[Tradesman]

Stock timings should prob be fine, if further problems might look to raise DRAM voltage .02-.05, which is above listed spec but quite safe (can normally go up to about .1 and still be safe, but I try and keep it as low as possible while maintaining stability)

[nhry]

I brought my DRAM voltage up to 1.545V from 1.5V.
Now I always get one BSOD within minutes of starting up but when I restart it will run fine for the rest of the time until I leave it off for a couple of hours. What else can I change?

[GSKILL TECH]

The two kits may be incompatible. Did you purchase them together or seperately?

Thank you
GSKILL TECH

[nhry]

I bought them separately, but they are the exact same model so it should be compatible right?

[Tradesman]

In a perfect world, yes they should be, but you can take a bunch of sticks all the same model and run into ones that won't play well with another. This is why most DRAM makers sell in kits of 2-3-4-6-8, they pretest the sticks that are in a set (even then you might catch a bad pair.

May try to up the DRAM voltage a bit more, maybe 1.57 or 1.58, the extra juice might overcome differences (and yes it's safe....could go even higher safely, up to 1.6 but I try to use as little as possible)

[nhry]

So I've tried a variety of configurations over the weekend and nothing is working. I'm running my computer with 2 sticks instead of the 4 right now. Is there anything else I can do to make all 4 sticks work together?

[Tradesman]

Could try the DRAM at 1.58 and NB 1.4.... or .....have you tried loosening DRAM to say 9-9-9-27

The Gskill folks might have something more...but not sure where they are/have been

[GSKILL TECH]

I bought them separately, but they are the exact same model so it should be compatible right?

No, even the same exact model memory may have compatibility issues with each other which is why we have match tested 8GB, 16GB, etc. etc. kits. Otherwise we would just sell individual modules and you can purchase as many you need.

Thank you
GSKILL TECH

[nhry]

So do I have to resign myself to running only 2 sticks of memory or is there something I can do to run 4 sticks?