Memory: Quad-Channel With FB-DImms
Four memory slots on the Skulltrail board
Since the D5400XS motherboard is equipped with the 5400 workstation chipset, which supports neither DDR2 nor DDR3 memory, the Skulltrail system can only be equipped with FB-DIMM modules. Fully buffered modules were originally developed for use in workstation and server systems and were never meant to find their way in desktop computers.
At their core, FB-DIMMs are a refined type of DDR2 memory that uses a serial data connection to the memory controller instead of a parallel one. This makes it completely incompatible with standard DDR2 and DDR3 memory.
Blue - DDR2-800 FB-DIMM Engineering samples (not in stores); Silver - DDR2-667 FB-DIMM
Compared to DDR2 and DDR3 memory, FB-DIMMs implement more error correction protocols. While this is positive for data integrity (think server environments, here), the downside is that they also cause a performance hit and cannot be turned off.
Even the temperatures of the FB-DIMM modules can be monitored.