Frequent BSODs on Windows 7 64-bit (mostly ntoskrnl.exe)

[boxhell]

Hi,

I've been having random crashes on my computer for quite awhile now (several months at least). Recently the crashes have become more frequent and are now happening at least once a day. Many times after a crash, the computer crashes up to three times again during start-up before finally starting up properly. The crashes are seemingly random and can happen during gaming, browsing, watching videos or simply while the computer is idle (or at least while I'm not actively using it). As you can imagine this is seriously hampering the usability of this computer.

I have checked that there is no over-heating.
I have tested my RAM with memtest86 but found no errors.
I tested my HDD with chkdsk and again found no errors.
I checked and updated my drivers and fiddled with the BIOS power save settings, to no avail.
When I checked the volts on my PSU, I ran into something interesting. Speedfan reported the 12V rail putting out only 9,8V, Everest had it at under 5V(?!) but the reading in BIOS was 11,8V. So I'm guessing this is just a case of Speedfan and Everest misreporting, as I hear they are wont to do.

I am at end of my expertise here. I can only guess that it might be related to my HDD starting it's dying knell or perharps my PSU being underpowered. I'd like to know whether any of you with more know-how would have any insights before I try to secure another PSU and a new HDD.

SYSTEM SPECS
CPU: AMD Athlon II X4 640
RAM: 2 x 2.0GB Dual-Channel DDR3 RAM @ 666MHz
GPU: NVIDIA GeForce GTX 460 1GB
PSU: Corsair 550VX (550W)
OS: Windows 7 Ultimate 64-bit

I have attached my latest minidumps here but there is a whole heap of the more. Thank you for any tips and insight you might have in this matter.

 

[Mark56]

Hi, the minidumps show a selection of different error codes but two are significant in that they both state Memory Corruption.

Memtest unfortunately can miss minor errors. To test your memory pull out both sticks and clean the contacts with a soft pencil eraser and then just fit one back in place. Run the PC for several hour or until it crashes, then swap the sticks to test the other one. You will proably find that only one of the sticks causes errors.

 

[boxhell]

Hi again,

I have now ran both of my memory sticks on their own, even in RAM slots 1 and 2 separately, and I encountered no crashing at all. As soon as I put both sticks in together the BSODs continued.

So it seems the problem is with some process that goes on when there are two or more RAM sticks installed. I am running the RAM in dual-channel mode. Could that be a possible source for this problem? What about installing the sticks in slots 1 and 3 or 3 and 4, for example. Could something like the pairing of RAM slots conceivably help with this issue?

E: I just checked my BIOS settings and there are a lot of RAM-related options I don't understand.

DRAM Bios Settings: (* denotes the current setting)

FSB/DRAM Ratio (*Auto / 1:2 / 1:2.66 / 1:3.33 / 1:4)
DRAM Timing (*Auto / DCT1 / DCT0 / Both)
DRAM Drive Strength (as above)
DRAM Advance Control (as above)
1T/2T Memory Timing (*Auto / 1T / 2T)
DCT Unganged Mode (*Enabled / Disabled)
Bank Interleaving (*Auto / Disabled)
Power Down Enable (*Disabled / Enabled)
MemClk Tristate C3/ATLVID (*Disabled / Enabled)

Would changing any of these settings possibly be of help?

I greatly appreciate any help and insight in this matter.

PS. the two RAM sticks are of the same make and model, so there should be no compatibility problems between them.

 

[Mark56]

I have very little knowledge of all the RAM settings available but as it runs ok with just one stick I would assume the settings are correct. Looks like most of the RAM settings are on Auto so I would leave them as they are. If the PC had been running trouble free for any length of time since you owned it then the settings should not be changed.

To run in dual channel mode you need to have the sticks in 1 & 3. Try that and let me know what happens. If running on just one stick it should be in slot 1.

When you ran Memtest86+ how many passes did you let it complete? It should be run for a minimum of 8 passes.

 

[boxhell]

Ah, I see. I thought I was running in dual channel mode all along when I actually wasn't. Got confused by CPU-Z, which told me the number of channels is 2, but as it turns out they are unganged, ie. in single channel mode. Thanks for clearing that up for me. I'll switch the other stick to slot 3 and see if it has any effect.

I don't remember how many passes I ran memtest86 through. It was on all night, for what it's worth. The thing that bothers me is that I have run both sticks separately for extended periods of time, several days and upto a week, without a single hitch on either one of them.

EDIT: Actually, I found out my mainboard manual says the sticks need to be in slots 1 and 2 for dual channel mode. As soon as I changed them to 1 and 3 the number of channels was reduced to 1. I also figured out that ganged and unganged are, apparently, both dual channel modes. Now CPU-Z just says that I have a single memory channel and the DC mode is greyed out. So I think I'm now running in single channel. Have to see if this helps at all.

 

[Mark56]

This will give you some more information on dual channel and ganged and unganged mode.
http://en.wikipedia.org/wiki/Dual-channel_architecture

And this has a mass of information all about RAM.
http://www.bleepingcomputer.com/tutorials/tutorial122.html

Normally on a motherboard the two RAM channels are identified by different colours on the slots. Slots 1 & 2 are one colour and slots 3 & 4 would be another colour although there are exeptions to the rule. Obviously your motherboard manual will give the appropriate information.

One of the most important things to check is that you have the correct voltage set for the RAM you are using.

Have you overclocked the CPU? if so you might find that that is contributing to the problem so I would suggest you reset it to default.

Going back to your opening post in respect of the voltage readings. The Bios would give the most accurate read out but it may be worth checking the PSU out puts with a volt meter just to be sure.

 

[boxhell]

I have been running my memory in single channel mode now for over a week without a single BSOD. Quite obviously the problem has to do with the memory being in dual channel mode because as soon as I switch the memory slots, the BSODs return. I'm guessing the core of the problem lies with my motherboard but I have also flashed the latest BIOS updates, so I'm not sure how to go about trying to correct this situation. Frankly, at this point, I'm quite satisfied with just running my memory in single channel and let the issue lie, at least for now.

Anyway, thanks, Mark56 for all your insight and helpful information about RAM architecture. Next time I'm faced with similar problems, I will be way more knowledgeable and prepared. Glad to see there are people willing to offer their expertise and advice to strangers on the internet. What a wacky world we live in.

 

[Mark56]

The route of the problem still remains a mystery but glad to hear you have got the system stable and usable.