ReadyNas 4312 Optional 10Gbe Modules

The 10GbE of the 4312X is not a user-instal;lable option for the 4312, as best I can tell.  I know it's a special mezanine card, not standard PCIe.  I also see nothing in Netgear's documentation that says there is any 10GbE option except to buy the "X" version.  However, my 4220 is equipped with an Intel X540-T2, which I have confirmed is also recognized by my older 4200V2.  It has no Netgear marking and as best as I can tell, it has no special firmware.  I don't even know if it came with it, as I purchased used.  So, I suspect that one would work just fine in the 4312.  But there appears to be only one PCIe X8 slot in a 4312, so you could only install one; and doing so would prevent later installng the SAS controller for expansion modules.

Amazon sells one with a 30 day money-back guarantee, so you could give it a shot (and let us know how it goes).  It's a bigger reward with some risk, but they sell for about half price on eBay.