Thanks for the feedback SHD.
Please see the attached screen grabs of the RAM Temperature and Memory Fan Speeds I'm experiencing.
1) Shows RAM Temp (45-46deg C) and Memory Fan Speed ( 1891rpm ) with original 2GB of RAM fitted.
2) Shows RAM Temp (57-65deg C) and Memory Fan Speed ( 3003rpm ) with New 8GB of RAM fitted.
3&4) Shows RAM Temp (57-65deg C) and Memory Fan Speed ( 3003rpm ) with both original 2GB & new 8GB of RAM fitted (I know not to do this normally, this was fitted purely for test purposes).
5) Shows the RAM modules in question ( 2 x 1GB Micron, and 2 x 4GB Hynix).
As you can see with the new 8GB of RAM installed Memory Fan Speed increases from 1800rpm to 3000rpm (too noisy), and the 4GB RAM modules run at a much higher temp (presumably causing the increased fan speed).
In Summary.... Are the increased temperatures and fan speeds normal?
For your info I've also updated the BIOS to the latest version v02.38, and installed an Intel 320 series 300GB SSD.
If I can get to the bottom of the issue above I intend to fit a second Xeon 5160 processor.