I don't know if this is in the right category. If not, sorry. I looked for an answer to this problem many other places, make that EVERYWHERE. Responses always address incompatibility (the component companies list these as compatible), bent pins (which I doubt) or Windows 32-bit systems (which I do not have).
I corresponded with Supermicro for months. I ran RW-Everything and verified that the RAM amount was changing. The problem never stayed in the same place. Sometimes the total installed (Control Panel<System) was sometimes 96GB, 128GB, 72GB and only once 144GB. Supermicro told me that either the motherboard was defective OR the RAM was incompatible with the processors. The customer service rep said if the memory is not compatible
to Intel MRC code, this kind of problem might also happen and to send it back so they could check. They didn't.
I RMA'ed to Supermicro. They sent it back--problem not found. Diagnostics report mentioned nothing about checking the Intel MRC code and they ran tests with only 6 sticks or 2GB each of RAM (different model number than mine) and 2 CPU's that were also different than mine. I never had a problem with 6 sticks of RAM. The problem started when I upgraded to a total of 12 sticks. After adding the second set of six sticks, the RAM was not all showing as installed. I reseated the CPU's and the RAM sticks. The problem went away. When I added the remaining 6 sticks for a total of 18 sticks (144GB), the problem resurfaced. Re-seating did not solve the problem this time. Tried it many times, moved the sticks to different slots.
Again, all components were researched for compatibility. I used thermal grease and I know how to install components. I use a static bracelet grounded to the unpainted metal on the chassis. Just wanted to get this obvious stuff out of the way.
Visual inspection of the CPU's shows no problems on the gold pads on the surface. They're called pins, but they are flat on this model number. The motherboard just came back from the factory, and they claim it is in perfect condition.
I'm really stuck. Each reboot still shows a different amount in the System section of the Control Panel. I know I probably need to buy something new (wish it weren't so), but I don't want to re-buy everything.
Something is wrong here. If anyone has ever seen anything like this before, you'd really be helping me out a lot.
Here's my build:
MOTHERBOARD: MBD-X8DAH+-F(-O) (newegg) - dual CPU board
CPU1: Intel Xeon Six-Core X5690 3.46GHz
CPU2: Intel Xeon Six-Core X5690 3.46GHz
18 sticks of RAM: 8GB - KVR1333D3D4R9S (all the same model number for total of 144GB)
ACTIVE HEAT SINKS: Intel BXSTS100C
VIDEO CARD: EVGA nVidia GeForce GTX 580 3GB
SOLID STATE DRIVE: Crucial M4 2.5 inch 256GB
O/S: Microsoft Windows 7 Professional 64-bit
CHASSIS: Supermicro CSE-745TQ-R1200B
No RAID set up.
I do have the BIOS enabled for AHCI.
I wanted to think it was one of the CPU's but moving them seems to change nothing and with only one CPU installed, the problem persists. Any ideas about where I can research next would be appreciated.
I don't know what this is. If you tell me, I will look and try to report it back to you. Thank you for replying.
I just got the exact same issue, it seems we have the same motherboard, line of processors, and ram brand so i guess there is some kind of incompatibility going on here.
Whats strange is without making any physical changes, i can have between 48GB and 72GB(72GB being the amount installed) of ram available, right now its at 59.9GB, seemingly at random this changes after each reboot, also are you using vt-d, cpu spread spectrum or any other non-defaults? im considering resetting to defaults to see if that helps.
Surly this has happened to someone else before, right?
Tried reinstalling windows yet? When checking the BIOS the RAM is always at 144gb, or is it just from windows that it mis-reports it?
Also try downloading and running a linux distro of your choice (64-bit ofcourse) to see if the problem is windows-related.
No it reports incorrect amounts in the BIOS too, i dual boot both windows and linux already and they both have the same issues :v
Im in the middle of cleaning right now so after i'll rebuild all my machines and clean out the dust and see what happens, its winter here so maybe the cold is causing issues but by the sounds of OP's post that wont help.