I am concerned the memory usability difference is only seen inside the Operating System. To better diagnose this, would you, please, confirm the following?:
1. What is the exact board model inside your Intel® Server Chassis SC5650DP?
2. What is the BIOS/firmware ver. running on the board?
3. What is the manufacturer and part number of the memory modules?
4. Is your system experiencing a performance scenario? If so, please, provide the following:
4.1. Please, elaborate more on the performance situation.
4.2. What troubleshooting have you performed so far?
5. Is the Operating System running with the latest updates/patches?