Issues with memory in OC'd system

[Dadofamunky]

Well, my Vista system is running unacceptably slow. I've determined that there is some kind of memory issue. Linpack only detects 80-160 MB of free memory in the 8 GB system. 3DMark (both '06 and Vantage) only detects a total of 1 GB of memory in the entire system and reports that after every test run. Also, the "Windows Experience" pseudo-benchmark gives a memory score of 3.5. This was at 5.9 before.

I began troubleshooting by removing two memory DIMMs to get to 4 GB. Same issue - unacceptably slow bootup and application starts, Linpack does not see the correct amount of free RAM.

Swapped out the first two DIMMs for the second pair, same issue.

Placed two DIMMs in the other 2 DIMM slots - same issue.

Finally, reset the BIOS to defaults. Same issue.

In all cases the system behaves like a system with 1 GB of RAM, and that level of memory appears in my tests.

This is looking more and more like a motherboard problem. Sigh. I thought I was finally done with this damn thing. I haven't bothered running MemTest yet: I'll probably be doing that over the next hour or so.

My question is: what is the recommended and maximum voltage settings for the Intel P35/G35 northbridge? I'm concerned that I may have gotten too ambitious in my OCing and fed too much voltage into my NB, damaging the chip.

My highest NB voltage setting was 1.37V. CPU was set to 1.35 and there did not seem to be any issues on that side of things.

See the sig below for the system config.

Here's the weirdest thing - the system passed every stability test I oculd throw at it; Linpack, Prime, OCCT and the WinMarks. At 1 GB RAM! The system plays media just fine - it simply takes its sweet time about everything. But I'm an impatient soul.

 

[faxon]

the p35 was made on 90nm process type, so i highly doubt you would have damaged it with 1.37v. sounds like a mobo issue either way

 

[Dadofamunky]

It's maddening. I've been trying to button this thing up for months. I even modded the case with another 140mm fan blowing onto the CPU/HSF. Now I'm looking at another damn motherboard swap. Ugh!!!

 

[Dadofamunky]

Another note: the system simply reports the full complement of RAM in the BIOS and the Windows Memory Diagnostic Tool reports no errors whatsoever!

I'm starting to wonder about the OS, frankly...

***EDIT*** It WAS the operating system.

I've just done a 4th re-install of Vista 64. It's running properly. No hardware swaps, thank God. SO... just another round of re-installs of apps. Fortunately, I finally got smart and moved all of my media to an external hard disk.

Here's a tip: NEVER install even a remotely suspect app of any kind in Vista 64. I suspect WinBubble 1.75 was the culprit in this case. This is the only program I had on my system that had any kind of odd or out-of-the-mainstream provenance. This thing probably caused problems in the OS's memory management routines. Linpack now sees 6.6 GB of free RAM.

I have never seen a less stable OS install in my life. Eleven months after I started this build, I still have not been able to completely call this system finished and working. Frankly, I'm not impressed with Vista, but now I'm stuck with it.