HP Z400 with x56xx processor with reg memory

[Yuriy_P]

I have a HP Z400 workstation. The motherboard supports the installation of the Xeon processor x5680. The processor supports register memory. I don't know if the motherboard supports register memory ?

[Huffer]

what processor do you have now? Different motherboards are used for the Intel Core models using non-ECC memory and the Xeon, which must have ECC memory. You can't put a Xeon onto a motherboard made for the Intel Core. 

[Yuriy_P]

The W3550 was originally installed, I replaced it with the W3680. 12Gb RAM with ECC

[Huffer]

Xeon to Xeon no problem

[Yuriy_P]

I have a need to increase the amount of RAM to 48GB, and Xeon W3680 supports RAM up to 24GB. So I want to install Xeon x5680 processor, it supports RAM up to 288gb.

[Huffer]

HP's official specs say the motherboard can only accept up to 16 gigs of RAM (4 x 4 gig DDR3-1333 ECC DIMM) and does not list the x5680 as a compatible processor, but then again did not list the W36xx series, either. They all have the same socket so your processor might work, but is going to be hamstrung by the motherboard. I would say the most memory you could even hope to install would be 4 x 8 gigs = 32 so no way to have 48 gigs on that machine that I can see. Even 32 gigs may not work and frankly is not likely to work. The capability of the motherboard is going to limit what the processor can do.