I doubt that you'd need a new case. Most of the ATX cases I've used were
also compatible with MicroATX boards. I hope that you have documentation on
the case.
It's possible that you'd need a new power supply. The P5V800 MX uses a 24
pin ATX 2 power connector. You may be able to get away with one of the older
20 pin connectors. (It ought to plug right in, without an adapter.) I have
read of people doing that successfully, but it's not guaranteed.
You mentioned a P4 1.7 GHz CPU. I hope that you're not intending to use it
with the P5V800 MX. It's a LGA board (land grid array, Socket 775), and
incompatible with a Socket 478 P4.
Address scrambled. Replace nkbob with bobkn.
"Eddie G" <egoldberg RemoveThis @amh.org> wrote in message
news:1144445077.072657.179760@j33g2000cwa.googlegroups.com...
> The P5V800 MX has dimensions of 8.6x9.6 and the P4t is 12x9.6, so I
> guess I need a new case, too.
> >> Stay informed about: mobo upgrade...do I need a new case?