Thanks for the question!
Check the below link for CPU compatabilty!
BTW, to my understanding ,difference b/w SAS and SASR is RAID controller. XVNSAS has only SAS controller. XVNSASR has SAS& RAID controller.
The list is here: http://www.intel.com/support/motherboards/server/sb/CS-022346.htm. The non-refresh board doesn't support Xeon 5200 or 5400 series processors, which is documented in the "Notes" section. In your case, the quickest quad-core should be X5365. You may also want to check Important information on support of Quad-Core Intel® Xeon® Processor 5300 series
The difference between a board S5000XVNSAS (non-refresh board) and S5000XVNSASR (refresh board) is the non-refresh board is not meant to work with 45nm CPUs; they are meant to work with 65nm CPUs; in some cases, you may see that the system will work fine, except that you will be left with an error message in the bios '19A' - voltage mismatched. No bios update will fix that.
However, the refresh board works fine with both 65nm and 45 nm CPUs.
One thing only to be 100% sure, check the pba number of the your board if it is non-refresh board and if your cpu is 45 nm.
Refresh board has a 'R' at the end.
If your board is a non-refresh board, then only 65 nm cpu worked fine on it.
The only exception board with pba starting Dxxxx that works with the 45 nm are:
So, from the compatibility list:
If you have a board S5000XVNSAS (non-refresh), and you want to use a cpu X5470, it wont work or will give an error message as the CPU is a 45nm technology. Any 65 nm CPU like E5310 etc should work as long as the minimum bios version requirement is installed.
All the best,