I am building a server based on ASUS MB Z8NA-D6 motherboard. I have already bought(mistakenly) two ram modules: Kingston KVR1333D3D4R9S/4GI , which is enlisted as compatible only with Intel motherboards. But there are these KVR1333D3D4R9S/4G modules(different in last character of part number), which are compatible with ASUS motherboard(and many others like Supermicro). So my first question is, will the KVR1333D3D4R9S/4GI modules work with asus board? Second question, do I need three modules when buiding a server with Xeon 5507 processor, or is it possible to use only two modules(and ofcourse have only dual channel)? And third question, is it possible to use two KVR1333D3D4R9S/4GI modules and one KVR1333D3D4R9S/4G module together?
Ok first off those Dimms you listed are standard DDR3 ECC modules they should work with pretty much any motherboard manufacturer. Just because its not on the the support list for the motherboard does not mean it wont work it just means they haven't tested it. As far as your question about mixing two different models of RAM I wouldn't recommend it I would make sure you find the exact same module to pair it up with or you risk instability and performance loss. You can run just two Dimms if you want, but if it has triple channel capabilities you might as well use it, but it will work in dual channel mode also.
I am worried about using non tested ram modules, because I bought them with xeon 3400 and intel S3420GPLC motherboard only to find out about the requirement: "Supports 1-Gb and 2-Gb x8 devices only - Intel 3420 / 3400 Chipset Memory Requirements". These rams are x4.