The Xeon 5500 series processor was stated to only support 1 DIMM/channel at 1333Mhz, and the Xeon 5600 series processor to support 2 DIMM/channel at 1333Mhz. Are these numbers still correct on the X8DTU-F, X8DTU-LN4F and X8DTU-6TF+? I have seen some reports that this limitation is not from the CPU itself, so I wonder if more recent BIOS updates have changed this situation.
The situation remains the same without any change. The BIOS does control the speed. However, it’s set by following the specification. Any setting beyond the spec will not be supported by the CPU.