GA-B75M-D3H No Post with 4x4GB (BIOS F13)

[Krisbee]

RE: GA-B75M-D3H No Post with 4x4GB (BIOS F13)

Have a long running system with 2X4GB sticks of memory in the two white slots.  After adding 2 more 4GB sticks of memory  it fails to get to POST. The fans spin and that's all when the PC is powered on.

All four sticks are the same make/model/spec: four of 4GB CORSIAR XMS3  CMX4GX3M1A1333C9C. All four sticks are known to be working.  (See update below.)

With just two 4GB memory stocks either in the two white or two blue slots the PC boots and operates as expected.  So all four slots appear to be functioning.

The board has been rock solid since it was first in use, so I guess I might need to adjust BIOS memory settings to get it to boot with 16GB and all four memory slots occupied.  The BIOS memory settings have always been on AUTO.

What do you think?  if the BIOS memory settings need adjusting what should they be?

Update: Seems I was wrong, the original two 4GB memory modules  were a matched pair with the label: CMX8GX3M2A133C9 they have an XMP profile.  The other modules are both CMX4GX3M1A133C9.

After my attempts to get the 4 sticks working today, I appear to have left one of each type in the machine in the blue slots, so need to sort that out irrespective of making any BIOS changes.

But I would still have thought putting the two CMX8G3M2A133C9 4GB memory sticks in the white slots and the other two CMX4GX3M1A133C9 4GB memory sticks in the blue slots that the system should have booted to POST, but perhaps I'm wrong.

[lapioks]

Try using 3 slots.

[Krisbee]

Try using 3 slots.

Did that when I hit the problem and the PC does no reach POST (no deep codes) with three slots in use.

Just to re-iterate:

Original set up -   2 X 4GB CMX8GX3M2A133C9  in white slots boots, never any problems with BIOS default memory settings.

Add 2 X 4GB CMX4GX3M1A133C9 to blue slots. PC doesn't reach POST.  PC fails to boot with four slots occupied  - all possible variations tried.

With just any two memory slots occupied the PC boots.  These combos all work:

2 X 4GB  CMX8GX3M2A133C9
2 X 4GB  CMX4GX3M1A133C9
1 X 4GB  CMX8GX3M2A133C9 + 1 X 4GB CMX4GX3M1A133C9

The last combo was accidentally used and would imply a mix of the two types of memory modules do work together.

This PC is in constant daily use and a future attempt to get 4 X 4GB to work will have to wait for a day or two. Planned test is to start with the two 4GB  CMX4GX3M1A133C9 memory sticks in the white slots, boot and enter BIOS to check the default auto memory settings. Boot Windows ( not my normal OS) to use CPU-Z to check JEDEC/XMP profiles and see  if there is an XMP profile at 1.6volts.  Re-boot and bump DRAM voltage to 1.55V, save & exit and shutdown. Fit the original two 4GB CMX8GX3M2A133C9 sticks and re-test.  If PC still fails to boot, will have to return to two sticks only and re-test with BIOS memory setting "Performance Enhancement" changed form "Turbo" to "Normal".  If PC still fails to boot with 4 x 4GB in place, will have to re-test starting with two sticks only and enter BIOS to change "command rate" from 1T to 2T.