The system appears to run fine, except that during boot-up, it emits some mysterious beeps.
First, there are two short beeps, a high-pitched beep followed by a low-pitched beep.
After about a second or two, there are three short beeps, all of the same pitch.
Lastly, there is the final POST beep, just before the OS boots.
It is the first five beeps that concern me. Does this count as one five-beep code, or two codes, one with two beeps and one with three?
The motherboard manual doesn't list this particular kind of beep code. The BIOS is made by AMI, and there are some beep code references on the web, but none that list my exact beep code. Two beeps could mean "parity circuit failure" and three beeps can mean "base 64k RAM failure". I doubt the five beep code is relevant, as that means "CPU failure" (I don't think the system would boot into the OS with a failed CPU).
I've worked with SuperMicro on this. After typical trouble-shooting (removing all components except CPU, RAM and PSU), shuffling the RAM around to different slots, etc, they RMA'ed the board. In fact, they wanted me to send the whole system so that they could further diagnose it. Unfortunately, I don't want to be without this system for any length of time, so I just got a new board under cross-shipment. The new board beeps the same as the old!
I just RMA'ed the memory. Now, prior to the POST beep, there are four total beeps:
One beep, about two seconds of silence, then three beeps.
Usage-wise, the system seems fine. No crashes or wacky behavior or anything remarkable (although it's usually under extremely low load, just shuffling bytes around).
So, now I've replaced the motherboard, and replaced the memory. Assuming I didn't get two bum boards, and didn't get two bum memory kits, the last thing to try is the CPU. I doubt that there is a problem with the CPU, though, but I don't know what else to try.