ok here is a temporary workaround  on my example Originally I had installed 4 GB / 4x1GB in slots 1-4 (white ones) I wanted to upgrade to 16GB / 8x2GB And obviously had a same problem as topic starter But I managed to work all memory in following way: Clearly it is a BIOS bug. I'm using A11.  For DELL It would be really nice to fix it at last
Hi all, I am at wit's end trying to get the most of my memory upgrade. I am running 64-bit Windows7 on Dell Precision T5400 single quad-core Intel Xeon E5405. Motherboard 0RW203. BIOS version A11 Got eight identical sticks of 2GB ram (totaling 16GB) and installed it on all available slots. Noticed on Windows properties - Installed RAM 16GB (4GB usable). Tried to play around with virtual memory allocations, but no success. Checked BIOS and it showed all 8 slots occupied with 2GB ram, but installed memory is 4GB. Don't see any options to tweak BIOS setting for it to recognize all 16GB ram. Checked each stick individually and all play nice and the CPU-Z reports them installed as well, ruling out slot or motherboard issue. I suspect its a BIOS issue and I would be grateful for anyone who can suggest a solution. I will be happy to provide additional information as requested. I inherited the machine, so RMAs and returns are out of question.
Installed RAM 16GB, only 4GB in BIOS - Precision T5400