F3-10666CL9D-8GBRL and MSI 785GM-P45 Woes

[ram]

I recently purchased F3-10666CL9D-8GBRL to go along with my MSI 785GM-P45 motherboard. I am trying to get the RAM to work in dual channel mode with my 4GB DIMM in slot 1 and the other in slot 2 as instructed in the motherboard manual, but in this configuration I am always getting numerous errors with memtest86 v4.0.

If I use each DIMM on its own in slot 1 for a total of 4GB everything works well. I can run multiple runs of memtest86 without a single error, but attempting to pair the sticks has just produced errors.

I have tried:
-putting the DIMMs in slot1/slot2
-putting the DIMMs in slot3/slot4
-manually specified the tCL 8 - tRCD 8 - tRP 8 in the BIOS with a command rate of 2T (tRAS only has an auto option)

I am lost as to what to try next. Am I correct in assuming it's not the RAM since each stick passes memtest86 on its own?

Thank you for any ideas you might have!

[Tradesman]

Could you post your BIOS settings for DRAM Timings and the voltages being used in the BIOS.....also, do you have the latest BIOS?

[ram]

Thank you for your help...

To answer your questions
1. Here are my DRAM Settings

DRAM Timing Mode: I have tried D0, D1, Auto and Both
CAS Latency (CL): 8 (also tried 9 and Auto)
tRCD: 8 (also tried 9 and Auto)
tRP: 8 (also tried 9 and Auto)
tRAS: Auto
tRTP: Auto
tRC: Auto
tWR: Auto
tRRD: Auto
tWTR: Auto
tRFC0: Auto
tRFC1: Auto
tRFC2: Auto
tRFC3: Auto
tRWTTO: Auto
tWRRD: Auto
tWRWR: Auto
tRDRD: Auto
Command Rate: 2T

2. The voltages are currently set to the default values, though I did attempt to up the RAM voltage to 1.6V without any change in behavior (8 GB fails, 4 GB works)

3. My BIOS is currently the latest revision from their website (v11.8)

[GSKILL TECH]

Timings should be 9-9-9-24

Did you try single channel? Try slots 1 and 3, then 2 and 4.

Thank you
GSKILL TECH

[ram]

Timings should be 9-9-9-24

I have tried

CAS Latency (CL): 9
tRCD: 9
tRP: 9
tRAS: Auto

tRAS only has one option, Auto. Would this in effect be 9-9-9-24?

Did you try single channel?

Yes...and single channel passes memtest86 without any problems on both sticks

Try slots 1 and 3, then 2 and 4.

I will try this, but the manual says to use 1/2 or 3/4 Would 1 and 3 be single channel?

Do I need to do anything with the voltages?

Thank you again for all your suggestions...I am not an overclocker...just want to get the RAM working at it's base settings.

[Tradesman]

What CPU are you running? Some won't go over 1066 in dual channel

[ram]

What CPU are you running? Some won't go over 1066 in dual channel

I have an Athlon II X2 250 Dual Core

If I wanted to give 1066 in dual channel a shot, what settings could I try?

Any suggestions on voltages to use?

[Tradesman]

Raise NB .1, raise HT .075 to .1, raise CPU (vCore .075), and RAM +.075

[ram]

Raise NB .1, raise HT .075 to .1, raise CPU (vCore .075), and RAM +.075

It finally worked!!! Thank you so much for the suggestion! I ran memtest86 over night with the DIMMs in Slot 1 and Slot 2.

Not knowing how this works behind the scenes, a few last questions for you:

My BIOS had a setting of "Auto" for my CPU Voltage, CPU-NB Voltage and DRAM Voltage. I modified "Auto" for CPU Voltage and CPU-NB Voltage to the largest value which my BIOS did not denote as "Unsafe" (it highlights unsafe values in red).

What I ended up with was
CPU Voltage: 1.442 V
CPU-NB Voltage: 1.199 V
DRAM Voltage: 1.578

Questions
Is there anything else I need to do if these settings pass memtest86 for multiple runs?
1) Are these voltages OK to use so long as they aren't marked as "Unsafe"?
2) Do I need to run anything to test these settings in terms of the CPU (if so, can you point me in the right direction)?
3) Is it worth tweaking these voltages to find the lowest value for which the memtest86 passes or should I just call it a day?

Thanks again for all your help!

[Tradesman]

Glad to hear it, On your questions 1) should be good, 2) Yes 3) Not really, should be fine 4) Yes, suggest writing down all your setting for a fallback, then can try lowering voltages in gradual small increments