I have an M6400 running BIOS A13. 8GB DDR3-1600 RAM installed (4x2GB).
I rum Memtest86+ and reports the memory is being access at 3,917 MB/s. That seems awfully slow for DDR3. On my other units running DDR3, memory speed is closer to 8000 to 12000 MB/s. This memory of speed of less than 4000MB/s is more like DDR2 ram speeds.
I have allowed Memtest86+ to run for a day on this machine with no memory errors and no over-heating.
I have reset the BIOS to factory defaults...just in case.
All four memory modules are identical in maker and model (I am OCD like that).
Memtest86+ is reporting the memory bus running at 561MHz (DDR3-1123).
The machine is still in good working order (or it seems so) and I would like to keep it around for some low level computing tasks, but not if this memory speed is indication of some sort of chip failure.