IBM x3650 M2 : 8x 2GB installed, but only 4GB recognized???

[CougTek]

Any idea what would cause an IBM server x3650 M2 to see only a fourth of the RAM installed? This particular server originally had 8GB installed into it and only detected 4GB. I needed more, so I added 4 other 2GB sticks (from other similar servers). It still only sees 4GB. I disable the memory mirroring in the BIOS, but no goal scored.

I don't have a lot of experience on those server models. The servers were purchased in November 2009, so no more warranty.

 

[ddrueding]

I'd probably start with pulling and swapping memory to find out which slots and DIMMs are being detected. Another place to try would be to down the timings to very conservative settings to make sure all is being detected.

 

[sdbardwick]

From the troubleshooting guide:

1. Make sure that:v No error LEDs are lit on the operator information panel.
     v Memory mirroring does not account for the discrepancy.
     v The memory modules are seated correctly.
     v You have installed the correct type of memory (see “Installing a memory
        module” on page 206).
     v If you changed the memory, you updated the memory configuration in the
        Setup utility.
     v All banks of memory are enabled. The server might have automatically
        disabled a memory bank when it detected a problem, or a memory bank
        might have been manually disabled.
2. Check the POST event log for error message 289:
     v If a DIMM was disabled by a systems-management interrupt (SMI), replace
       the DIMM.
     v If a DIMM was disabled by the user or by POST, run the Setup utility and
       enable the DIMM.
3. Run memory diagnostics (see “Running the diagnostic programs” on page 70).
4. Add one DIMM at a time. Install the DIMMs in the sequence that is described in
     “Installing a memory module” on page 206.
5. Reseat the DIMMs.
6. Replace the following components one at a time, in the order shown, restarting
the server each time:
     a. DIMMs
     b. (Trained service technician only) System board

 

[Mercutio]

Is the RAM you're using explicitly validated with that model?

 

[CougTek]

1. Make sure that:v No error LEDs are lit on the operator information panel.

I guess that's the yellow square led with an exclamation point into it. Yes, it's lit. I'll make sure all the memory banks are enabled (all 8 slots next to the single CPU are filled).

 

[sdbardwick]

Troubleshooting guide is here: http://download.boulder.ibm.com/ibmdl/pub/systems/support/system_x_pdf/00d9271.pdf
Manual is here: http://download.boulder.ibm.com/ibmdl/pub/systems/support/system_x_pdf/00d3225.pdf

 

[CougTek]

Is the RAM you're using explicitly validated with that model?

The RAM sticks I took were from other similar systems (7947-AC1 & 7947-52U) and those servers have worked non stop for the past three years. I guess that yes, the RAM has been validated for that model.

 

[CougTek]

Thanks

 

[Howell]

How many out of how many CPU sockets are filled?

 

[CougTek]

Two sockets, one filled. There are 8 memory slots next to each CPU socket. I've filled the 8 slots next to the occupied socket. All the others are empty.