Strange Ram Problem

[mavericace]

Hello,
Hello I have been having a heck of a time trying to figure this one out and would very much appropriate it if anyone has any ideas on whats going on here.

I have upgraded from 1 stick of 2gb of DDR2 ram to 2 sticks of 2gb DDR2 ram. Well after random errors and a couple of BSOD's listing PFN_List_Corrupt I decided to run some tests on the new ram.

Test #1 just ran memtest86 and came up with errors. Ram in slots 1 and 2 out of 3.

Test#2 I know that errors mean bad ram so I took one stick out trying to figure out what one was bad. Test passed.

Test#3 I switched the sticks. Test passed.

Test#4-6 I tested both sticks individually in each slot (I have 3 slots). All tests passed.

Test#7 Tested Ram in slots 1 and 3. Test showed errors.

In summary the two sticks do not work together at the same time. I also had memtest freeze on me when I tried both at the same time. This makes me think that the Ram is good and the Ramm sockets are fine. I also tried to reset my BIOS to default settings with no luck as well as downloading the latest BIOS.

For reference...

Ramm- http://www.corsair.com/twin2x2048-6400.html

MB- http://www.asus.com/Motherboards/Intel_Socket_775/P5NEM_HDMI/

Thanks guys.

 

[scout_03]

asus says board work single channel the corsair memory you got are mark to work on dual channel,see your link to find whats wrong

 

[mavericace]

I was under the impression that there was no such thing as "dual channel" ram and that that it was just a marketing ploy for selling purposes. Is this incorrect?

 

[ko888]

Your use of default BIOS memory settings are probably the root of your problem.

What is the make and model of your original 2GB DIMM?

Is there any DIMM voltage mismatch between the original 2GB stick and the two new 1GB sticks?

What about memory timings mismatch between the original and new?

 

[mavericace]

This is the ram I was using before.

http://www3.pny.com/2GB-PC2-6400-800-MHz-DDR2-Desktop-DIMM-P2390C31.aspx

Before I was using one 2gb stick now two 2gb sticks. I can not find where it lists the voltage for the old ram but my MB says standard is 1.8. Both the old and the new ram say they should be compatible with 800Mhz.

Just as a reminder the new ram works fine if it is only one stick at a time just not together and obviously I have not tested one of the new with my old since it is not advisable to mix and match.

 

[ko888]

This is the ram I was using before.

http://www3.pny.com/2GB-PC2-6400-800-MHz-DDR2-Desktop-DIMM-P2390C31.aspx

Before I was using one 2gb stick now two 2gb sticks. I can not find where it lists the voltage for the old ram but my MB says standard is 1.8. Both the old and the new ram say they should be compatible with 800Mhz.

Just as a reminder the new ram works fine if it is only one stick at a time just not together and obviously I have not tested one of the new with my old since it is not advisable to mix and match.

If you're not using the latest BIOS Version 0505 I would suggest that you update. Only do the BIOS update with one DIMM installed since that is what your motherboard is currently stable with.

With only one DIMM installed you need to go into the Phoenix-AwardBIOS CMOS Setup Utility and manually set your Memory Timing Settings before adding the second DIMM. Adding the second DIMM seems to change the memory bus load sufficiently that the [Auto] memory timings settings are causing instability.

In the Advanced menu --> Jumperfree sub-menu --> Memory Timing Setting

I would suggest changing the Command Per Clock (CMD) setting from Auto to [2 clock]

Save the changes, shut down and unplug the power cable.

Install the second DIMM, plug the power cable back in and power up.

If it passes POST without problems then it's time to run your memory testing utility.

Another suggestion is to also try changing the 1.8VDual Over Voltage Control setting from [1.880V] to [1.920V].

ASUS motherboards are known to be very finicky with memory even if they are listed in the motherboard's QVL.

 

[mavericace]

Thank you for the very detailed suggestions, I did update my bios when I had both of the sticks in so that could have been a issue. I am not at my computer right at the moment but I will certainly give them a try and let you know how it works out.

 

[mavericace]

I did exactly as ko suggested and his excellent advice has solved my problem. I flashed my bios to 0505 with only the one stick installed and changed my CMD settings from auto to 2 and now I am having no problems with my memtest.

I would just like to give a huge thanks to ko for the outstanding information. I do have some computer knowledge but there would have been no way that I would have been able to fix this problem on my own.

Huge thanks.

 

[mavericace]

Best answer selected by mavericace.