4 toshex: 1) official ... from asus page. 2) X3363 (xeon lga771, 4core/2,83GHz/12MB/1333MHz) ... difference between models is ... X3360 (4core/2,83GHz/12MB/1333MHz/95W) / X3363 (4core/2,83GHz/12MB/1333MHz/80W) / Q9550 (4core/2,83GHz/12MB/1333MHz/95W) ... so between this 3 is X3363 best option cause all have same specs ... but X3363 is lower voltage 80W vs. 95W / 95W ... that means that X3363 should be best cores for "lower" wattage (80W). 3) X5xxx can also work with LGA775 ... but must be some other (I mean) NB like X38 or P35/45 (you can google it to be sure).

Thanks for the answers. Just to be clear it's the official BIOS not modified right? I am thinking between X3360 (775 xeon), X3363 (modified xeon from socket 771) and Q9550 - 9550 is probably easiest and I don't aim for more than 3.5GHz so maybe I don't need coolers for 3.5GHz? Or maybe the Asus cooler that clips on the heatsink... shame X5000 cpu don't work - already ordered X5450 just to find out it doesn't work hahah.

4 toshex: 1) sure I think I use last bios update ... but still have issue with the CPU ID. 2) C0 or E0 not sure ... but maybe I can check it somehow. 3) for x48 is definitely a must "coolers" cause x48 is a heater ... and have issue also with "before" E8500 ... reached just 3,8ghz or somethin after "cooler" fix ... hit 4GHz with "EZ".

Hi, can you tell me if you made any bios mods for this CPU to be supported? Also is it C0 or E0 and which would you suggest? Also are the coolers for the chipset necessary? Thanks!