Random instability - Asus P5N-T Deluxe & 2 pairs of TWIN2X2048-8500C5D

[Sapphire]

Hello, in the past weeks I have encountered random forms of system instability; ranging from application crashes and data corruption to BSODs, meaning that my system can be perfectly stable running at full load for four days and then suddenly crash. Memtest shows no errors with all four modules in place after a fresh boot, after a crash, however, Memtest will return continuous errors. Please note that all tests were performed at stock voltages and clocks and the system was running flawlessly for 2-3 months before these problems started.

 

Testing:

 

• Exchanged power supply, Thermaltake ToughPower 650W
  
• 5-5-5-15:2T memory timings at 2.110V, tested with 667, 800 and 1066Mhz
  
• Increased motherboard voltage
  
• Tested every module separately in every slot
  
• Used a room fan to blow air into the side of the case to verify that overheating is not the problem
  
• Removed sound card, swapped graphics card
  
• Many hours of Intel Burn Test & Orthos; stable
  
• Memtest; stable, faults only occur after loading Memtest straight after a crash
  

 

 

 

Frankly, I am not even sure whether this was the correct place to ask about this issue, but I can safely say that I have run out of options and wouldn't know what else to test to identify the problem. Any comments are greatly appreciated.

[RAM GUY]

First this if you have not done so please test each set and see if you can isolate the problem to one of the sets. IE assuming you have tested them all one at a time with http://www.memtest.org and not had any errors??

The if they both seem to run properly one set at a time then with 4 modules I would suggest setting the memory frequency at DDR667 or DDR800 and set the memory Voltage to 2.1 Volts and set the NB/MCH/SPP Voltage to +.2 Volts as well and test the system with http://www.memtest.org. In addition, with some MB's (Mostly ASUS) you have to disable legacy USB in the bios when running any memory test.

[Sapphire]

Thank you for you response. I have tested each of the modules separately four times in different slots each so the memory seems fine. Instability occurs regardless of speed, I have tried 667, 800 and 1066. The RAM's default voltage is 2.1V, stability is still an issue even if I increase the RAM, NB, SB and MCH voltage. However, my two sets are not of the same version (they are both TWIN2X2048-8500C5D 2.1V), but the version number is not equal. Could this be an issue, keeping in mind that the system ran perfectly stable during 8+ weeks?

 

 

I am starting to believe that the problem may be a faulty CPU, but it seems odd that the system can run at full load for hours, days, or even a week and randomly crash while idling after long periods.

[RAM GUY]

Its hard to say Random errors like that can be difficult to track down. But have you checked the event log to see if any errors have been logged?

[Sapphire]

The error message in an app crash tends to be data corruption, failed decompression and so on, whereas blue screens tend to be memory related.

 

Example of my latest crash: Stress tested my system for 100+ hours with Orthos as well as Intel Burn Test, then sometime past the hundred hour mark memory faults start.

[RAM GUY]

That would suggest a thermal or Voltage problem maybe. What are the settings you have set for both CPU and memory?

[Sapphire]

Memory voltage is set to 2.110V, CPU 1.225V (if I remember right, it's the Intel recommended voltage). The temps seem fine as well, and the ram sticks pass memtest individually so I believe the board is bad.

 

I'm tempted to just upgrade to an i7 in the upcoming week instead, although as a last resort I will try to flash the oldest bios with 8500C5D support and give that a try.

[RAM GUY]

We can try and replace the modules if you like, please use the On Line RMA Request Form and we will be happy to replace them.

[NeverwinterMoon]

I'm having a problem similar to the one described in the original post. After several months of normal work one of the PCs with TWIN2x2048-8500C5D started having BSODs with different intervals. At first those BSODs were pretty rare but lately they happen at least once a day. There was no hardware change during the period of time I had TWIN2x2048.

 

I haven't done lots of tests, but what bugs me most of all is that Memtest seems to show errors only after a crash and no errors at all after turning PC off completely and testing in a while.

 

First of all, I used all the recommended settings for the memory.

 

Second of all, I tried this exact memory combo in another PC I have with totally different hardware and had the same story all over. Both PCs work perfectly with a different set of Corsair memory (not Dominator, something cheaper).

 

Why did I start having those crashes only several months after totally normal work and why those crashes are becoming more frequent?

 

How can I be completely sure if the memory is or is not faulty?

 

Thanks in advance.

[RAM GUY]

Let's get them replaced, please use the On Line RMA Request Form and we will be happy to replace them. Be sure to check the box that says “I've already spoken to Technical Support and/or RAM Guy.”