Now only stable in single-channel mode

[glennjames71]

Hi guys,

I have an AMD X3 720, ASUS M4A79XTD EVO and G.Skill F3-12800CL8D-4GBRM - all purchased about 8 months ago. Until about a month a go, the system was stable and the RAM ran happily at 1600 8-8-8-24-34-1N on auto volts.

However for about a month now, I have been major BSOD issue with error messages including bad_pool_header, pfn_list_corrupt, irql_not_less_or_equal etc. I have not updated any drivers or hardware and the BSODs came completely out of the blue. I have spent weeks troubleshooting and have tried all of the following and more: - lowering RAM speed to 1333 and 1067, setting voltage and timings manually for RAM and CPU and NB, trying looser RAM timings, running memtest (no errors), Prime95 (BSOD), running HD diagnostics, disconnecting additional drives, DVD, sound card etc, updating BIOS to the lastest version, updating drivers to the latest version, removing Windows XP and installing Windows 7 (which is even less stable for some reason).

The only way I can get the system stable is by running the RAM in single channel mode - if I do this then the RAM will once again run at all speeds including 1600 8-8-8-24-34-1N without any BSODs so far.

I don't believe the RAM is the problem as memtest has yet to report any errors. What I am struggling with is why I can only run in single-channel when for six months I had absolutely no problems? Is it the CPU and its flakey mem controller or is it a mobo fault?

Thoughts anyone?

[bobtin]

I am having the same type of problem with the asus evo 790 and the 1600 ripjaws F3-12800CL9D-4GBRL if I take one out it will run for one session but when I cold boot it after a few hours it will blue screen. Then if i put the other stick of ram back in it will run for another session. only when I cold boot with the same settings I had before will it blue screen. Also I am using the Phenom ii 550 x2 I can unlock it to a quad and that seems to work fine but something is wrong with this combination of ram/mobo. I have been trying every different combination of bios settings to get it to work but it just wont stay stable. I was going to make a new thread and saw this one so I figured I could kinda combine the two. I really dont want to have to buy a new mother board or diffrent type of ram.

Also memory tests found no errors on the sticks.

[GSKILL TECH]

Could surely be the CPU (memory controller embedded), try increasing CPU-NB Voltage +0.1V and NB Frequency x11 2200MHz and see if that helps.

Thank you
GSKILL TECH

[bobtin]

I think I did try something similar and it will decrease the ghz of the cpu, and I still had the same problem. When I did it though i took the cpu-nb voltage off of auto and put it at 1.35 i am not sure what i would put it at with +0.1v because i dont know what it was at on auto.

[glennjames71]

I have already tried setting the CPU-NB freq to 2200 and voltage to 1.2 as suggested in another recent thread by a G.Skill tech. At first I thought it had fixed the dual-channel problem as the system appeared to be stable with RAM at rated speeds. Short gaming sessions and a few loops of 'The Last Remnant' benchmark appeared to run fine.

However, running Prime95 give me a BSOD with minutes. I dropped the speed down to 1333 - BSOD and 1067 - BSOD. So I swopped RAM slots back to single-channel @ 1600 and Prime95 ran quite happily for 90 minutes until I stopped it. It really does seem that I am just unable to run dual-channel with this rig when it worked fine for months previously.

I have contacted ASUS and AMD: the ASUS tech suggested trying each stick in each slot at a time to rule out any memory\controller issues. I haven't had a chance to try this yet but I suspect it will work without any problems. I am still waiting to hear back from AMD.

[GSKILL TECH]

What slots do you have them in? They should be in the blue slots.

Thank you
GSKILL TECH

[bobtin]

Tryed all the slots but i did have them in the blue slots because the manual says to. Starting to wonder if its just the mother board that is faulty there are many other people with similar problems that have this same board. Might be looking into buying an MSI board soon.

[GSKILL TECH]

Send the memory in for new replacements first, to eliminate the possibility of memory being defective.

Thank you
GSKILL TECH

[glennjames71]

I have tried them in the blue slots and the black slots at 1600, 1333 and 1067 but the end result is the same - dual channel just doesn't work.

I would RMA them if I though that it would fix the problem once and for all but as bobtin says, there are many other people out there with similar issues and I've read plenty of similar threads where swapping the RAM out does not fix the problem.

I don't think the RAM is the issue here because surely faulty RAM is faulty RAM - single channel should fail as well?

[GSKILL TECH]

Indeed, most of the time it's the mobo.

Thank you
GSKILL TECH

[glennjames71]

Yes, I must admit that the motherboard is my top suspect too - when ASUS can't even be arsed to implement a 'turn the PC off just by pressing the power switch', feature you have to wonder what else they left out.

For a few hours todays I should be getting my hands on a Dell Optiplex 980 (Intel CPU, Dell mobo and intel chipset) so I'm planning on dropping my RAM in and giving it some Prime95.

I'm guessing that the RAM will work fine in dual channel but I'll post the results later for those interested.

[glennjames71]

So, I have now tried the RAM in a Dell Optiplex 780 SFF.

The speed was auto-detected at 1067 MHz and I confirmed dual channel mode in the BIOS and with CPU-Z.

Prime95 ran for over an hour without any errors, at which point I stopped the test and booted my systemrescue CD and ran memtest for over an hour - again without a single error. I know that two hours of testing is not conclusive but I reckon it is a fair test - my rig would not be able to manage it in dual channel.

As I thought, the RAM looks good and it is either the mobo or mem controller within the CPU.

[GSKILL TECH]

Glad to hear you were able to sort that out without wasting time RMAing memory.

Thank you
GSKILL TECH

[glennjames71]

I have just had the following message from AMD tech support: -

If you are no longer able to keep your system running stable in dual channel mode, problem may be with the CPU, motherboard, or memory. The 720+ will support up to DDR3 1333 MHz memory speed, anything above that would be overclocking. Overclocking any component may cause system instability and/or damage to a system. Since you were running the memory at 1600 MHz, damage may have occurred within the memory controller of the CPU or the hypertransport bus on the motherboard. At this point, the only way to troubleshoot the processor is to try it onto a different system or get it replaced. As for troubleshooting the motherboard, you would need to get with motherboard manufacturer. The only sure way to know is to replace the hardware component.

So basically, don't bother buying fast RAM and expect to run it at the rated speeds 'cos it may trash your system!

Great.

[glennjames71]

...and now for the really good bit. After testing my RAM in the Dell 780 earlier today, I was going to put the RAM back into my rig and I'll thought I'd try the old 'clean the contacts with a rubber eraser' trick. Dropped the sticks into the blue solts (a la dual channel) and fired it up with 2200 on the CPU-NB at 1.2V - Prime95 stable for 30 mins. Rebooted and set my RAM settings to how they were before all the BSODs started happening - 1600 8-8-8-24-34-1N auto volts and CPU-NB on auto freq and volts; I have just spent the last 50 minutes playing Crysis without any problems!

I'll keep monitoring for a few days but by my reckoning, either cleaning the contacts with an eraser or the act of simply testing the RAM on another platform may have solved the problem. How weird is that?