MA790FXT-UD5P: kernel panic

[fest3er]

The system

• MB: MA790FXT-UD5P
• CPU: Phenom II 965 black edition
• Hard drives: Hitachi_HDT721010SLA360_STF607MH3SL8YK, Hitachi_HDT721010SLA360_STF607MH3U8WAK, TOSHIBA_DT01ACA100_Y2RTLRHPS
• HD IF: SATA, non-raid
• Video: GeForce 9500 GS
• P/S: Antec SP-500, 500W
• RAM: G-Skill F3-10666CL7Q-16GBXH (running at 9-9-9-24); formerly F3-10666CL8D04GBHK (two sets)
• OS: Debian Wheezy, 64-bit, kernel 3.2.0-4-amd64, up-to-date
• Overclocking: none
• A/C power: via UPS

CPU temp almost never exceeds 60C; when it does, I blow the dust out of the heat sink and it drops to a reasonable 57C. Hard drives almost never get above 44C.

The problem
The system works fine until memory is filled and the system has to start dropping cached disk blocks. At this point, I almost invariably get a kernel panic or other GPF.

For a while, I thought it was a RAM issue, so I bought the 16GiB memory (4 sticks) and sent the 8GiB (4 sticks) back to G-Skill for testing. The new RAM wouldn't work well until I set the timings to 9-9-9-24.

I can fill the memory building Smoothwall v3.1 (either 32-bit or 64-bit), or manually read enough files to fill Linux's disk cache. Every time, as soon as the system needs more RAM, it crashes. I can even build in a KVM with 512MiB assigned and the system will still crash.

I really have no clue as to where to look next. Or how to look....
So what is likely to be the problem?

• Linux? I imagine I could build a custom 3.4 kernel, in the event 3.2 has a problem with paging.
• mainboard? Would there be any visual clues?
• CPU? Have the '965s' ever been known to have VM problems?
• Power supply? It's a fairly new supply; I doubt it's the source since the failure seems to happen only when RAM is filled, But I could put a scope on the various outputs just in case power is dicey.

Basically, I ask here to see if anyone has ever encountered similar problems with this mainboard/CPU combination.

Thanks!

[fest3er]

It would seem the last Wheezy kernel update greatly alleviated this problem. The system is far more stable than it was. But I did get a GPF earlier today. See attached.

According to this thread, it might be unreasonable that my PhenomII-965 is failing even though it hasn't been overclocked or overheated (beyond 65C or so).

[fest3er]

Still nothin' but trouble. Until I pulled two of the four 4GiB sticks of RAM. The system has been behaving since.

So now I've just seen this quote from absic's Very Important Info thread:

The Phenom II only supports 1333MHz DDR3—at least, officially—with a single DIMM in each memory channel. With four DDR3 DIMMs, 1066MHz is the standard. Such limitations are nothing new, of course. Previous Phenoms have long supported 1066MHz DDR2 memory, but only with a single DIMM per channel.

Does this mean that I really should run the RAM at 1066? (Whether it's the 4x4GiB at 7-7-7-21 or the older 4x2GiB at 9-9-9-24...)

Is there no other solution?

Is there a thread that illuminates the relationship between memory speed and memory timings? And even among the various memory timings?

[Vezina]

With 4 sticks 1066Mhz not more.
Timings 9-9-9-27-36 and 2T
CPU limitations.
If the sticks are not matched you will get troubles.
Try Ganged <-> Unganged as well.