I've been using the X9SCM for some years now. In the beginning i added (the absolutely correct) 4x 4GB non-buffered ECC memory, and i noticed that sometimes the board didn't boot (memory errors) or it did boot but unraid crashed after an hour, or a day. After a lot of testing i found out that if i just used the first 3 of the 4 banks (in the order DIMM2A, DIMM2B (the blue ones) DIMM1A) all worked fine, but if i also added memory to the last bank (DIMM1B) the errors reoccured... Fed up with it i decided 12GB was enough at the moment.

 

But now i'm in need of more memory, and recently i bought 4x 8GB modules (again, the correct ones according to the manual) also hoping that this time i could use all four modules, assuming there was some sort of incompatibility or other issue with the 4GB ones. But again, once i add the 4th 8GB module to the last (DIMM1B) slot, the system crashes after some time. Can take an hour, or a day, but it will become unresponsive and the only way is to pull the plug... with 3x 8GB the system runs fine. No problems at all. It is up 24/7 for weeks now.

 

I know this is not a very new or modern board, but i was hoping if this was familiar to someone? Or maybe anyone has an idea what is going on? Is this a known issue with this board? Am i missing some BIOS setting?

 

I mean 24GB in stead of 32GB is more than enough for my purpose at the moment, but i purchased 32GB and i want to see 32GB in unraid's system info!  

Most likely mainboard DIMM slot problem.

I haven't unstable problem for 4 modules on Intel or AMD platform.

Edited April 3, 20206 yr by Benson

Yeah, could be some hardware fault in the specific slot. I've cleaned it with air from an air-can and a anti-static brush, but did not help. Maybe there is a pin just a bit out of place, who knows. Btw, this is an Intel platform as well, the motherboard brand is Supermicro (server board).

You may check does any circuit track have problem and try to fix it.

 

I have 2 major memory incident, 1 module went bad and 4 new module burn by mainboard during expansion, but all problem fix after RMA replacement and change another mainboard.

Edited April 3, 20206 yr by Benson