F2-8500CL5D-4GBPK x 2 and Asus P5Q Pro

[Smegs]

I've been running one set (2x2GB) of F2-8500CL5D-4GBPK on my Asus P5Q Pro motherboard since 2009 without any trouble. My settings for all of that time have been:

DRAM Frequency DDR2-1066MHz
DRAM Voltage 2.0

I bought another pack of F2-8500CL5D-4GBPK to make it a total of 8GB. I put them in the two matching-color slots that were not in use.

On Memtest86+ 4.20, I've been getting errors, specifically on Test #5. I've taken my old sticks out and tested the new ones, and they haven't produced any errors. I've also tested my original sticks without the new ones, without any errors. I've also tried the following combinations, based on various search results on this forum and other sites:

all of the below with DRAM Frequency DDR2-1066MHz

DRAM Voltage 2.0
NB Voltage 1.40

DRAM Voltage 2.10
NB Voltage 1.40

DRAM Voltage 2.20
NB Voltage 1.40

DRAM Voltage 2.20
NB Voltage Auto

I've also tried Ai Clock Twister set to "Lighter" with a number of the above combinations.

I'm running the latest BIOS, and I've cleared the CMOS and set everything up fresh just to be sure. My PSU is, I believe, 850W, so I doubt it's a power supply issue.
The DRAM 2.20 and NB Voltage 1.40 has given me the best stability, only producing errors after several error-free runs of Memtest86+.

Does anyone have any suggestions, or should I just return the RAM and accept 4GB as my fate?

[Tradesman]

Couple of thoughts, what CPU and what OC is any? May want to try the NB a hair higher 1.43 or so to help stabilize the MC and DRAM, also could try raising the vCore a little on the CPU, with the extra DRAM if the CPU vCore is at a marginal setting for the FSB being run it can cause problems.

[Smegs]

I'm running it with a Intel Core 2 Quad Q9550 45nm, all stock speeds.

My errors are always coming in identical pairs; I'll get two identical errors with identical data/results at each error occurrence. They don't appear exclusively in any specify range of memory.

I've tried switching the new RAM for the old RAM in terms of slots (new in 0 and 2, old in 1 and 3), but that didn't change anything.

I've tried slowly raising the FSB voltage(up to 1.40 atm), as I've seen in a few other threads. I feel like every individual setting I raise is lowering the error rate, but I just haven't hit the right combination, yet.

To test each of these little changes, I've been running Memtest86+ and specifying Test #5, as it has been giving me a couple errors in less than an hour.

Just now, I set my CPU voltage to 1.225 as a start. I don't know the exact "default" for this processor, but I believe 1.25 is the maximum safe limit and I've seen numbers near 1.2 as common starting areas. I set NB to 1.42 (it only allows even numbers).



Results: after running for 30 minutes, I received my first string of errors.
Any other specific suggestions?

I'm going to up NB to 1.44 and let it run overnight to see what the results are.

To recap, current settings are:

DRAM Frequency: DDR2-1066MHz
CPU voltage: 1.22500
FSB: 1.40
DRAM: 2.20
NB: 1.44 (was 1.42 on previous run)
everything else Auto

[Tradesman]

Is it an Intel 9550 or 9650 maybe? If so try it at 1.25/1.26 for stock with 4 sticks

[Smegs]

I tried both 1.225 and 1.25 and I still ended up with errors after running Memtest86+ for around an hour.

And yes, it's a Q9550.

[Smegs]

CPU voltage at 1.26 produced errors.

Should I just down the speed to DDR2-800 and give up on 1066? Will that circumvent this?

[Smegs]

As a test, I set the memory to DDR2-800MHz and 4-4-4-12 and had the following settings:



FSB Termination Voltage 1.40
DRAM Voltage 2.10
NB Voltage 1.40

Memtest86+ ran for over 3 hours, completing multiple tests, without any errors.

Shouldn't this end up providing equivalent, if not slightly superior, overall memory performance?

Also, should I tune some of these voltages down for these speeds?

[GSKILL TECH]

Did you read the guide?

Don't forget tRFC should be 80, tWR 8, when attempting full slots.

Post pictures of BIOS and I can double check.

Thank you
GSKILL TECH

[Smegs]

My current settings are:







I wasn't able to find the tWR equivalent for my motherboard.

I've also had DRAM at 2.20 in past test with these same settings. I've also tested both 1.42 and 1.44 for NB.

[Smegs]

I found tWR as "Write Recovery Time"

I've changed it to 8 and I'm testing now.


I don't see any specific guide pertaining to my motherboard, but if there is one could you link it to me?

Thanks!

[Smegs]

Okay, I just tested with these settings:

DRAM Frequency DDR2-1066MHz
DRAM Timing Control Manual
CAS# Latency 5 DRAM Clocks
DRAM RAS# to CAS# Delay 5 DRAM Clocks
DRAM RAS# Activate to Precharge Time 15 DRAM Clocks

Row Refresh Cycle Time 80 DRAM Clocks
Write Recovery Time 8 DRAM Clocks

FSB Termination Voltage 1.40
DRAM Voltage 2.20
NB Voltage 1.44

everything else Auto


The results of this test were multiple errors. Is there anything else that I need to change?

[GSKILL TECH]

FSB Termination Voltage AUTO
DRAM Voltage 2.10
NB Voltage 1.40

If that doesn't work, try everything default, except DDR2-800 4-4-4-12 2.0V to test and see whether the modules can be compatible with each other.

Thank you
GSKILL TECH

[Smegs]

I had already tested 800MHz at 4-4-4-12 and they are definitely compatible, running for over 12 hours without errors. I've also been successful at 1002MHz with 5-5-5-15, DRAM 2.0, everything else Auto.

DRAM 2.1 and NB 1.4 produces errors.

I'm just going to stick with 1002. It's close enough, and more memory at a slightly lower frequency is better than less memory at a high one.

Thanks for all the help.

[GSKILL TECH]

The voltages must need some tuning then, because they should work.

Just for your reference, in case you want to play a little more, you can also try for the max frequency with CL4 timings. That should be quicker than current settings.

Thank you
GSKILL TECH