User has validated 40 Gb ram in 435MT.  Max probably 48 gb which was validated in 435T. “I have 4 sticks of Corsair Vengeance DDR3 1600 8 GB. I put them in one (it already had 2x4 GB), booted it up and Windows 10 reports 40 GB of RAM”
Hello and best regards! Got an old LGA 1366 motherboard 0R849J with a stock 920 i7, looking to upgrade to Xeon X5690. been ding some research and to what it seems, my board is compatible with that processor (stock motherboard, not looking in to making the purchase to after market options) and I was wondering where can I find BIOS update and IF is it needed at all or is it just a plug and play option? Thanks!! 
Studio XPS 435 MT, BIOS upgrade for Xeon X5690