Avid has announced support of Media Composer and Newscutter on the HP Z820 systems. See the links below to access the Avid documents relating to this.

Qualified PC Systems document
Z820 Configuration Guide

There is a networking problem that Intel can't seem to solve which has helped to delay this announcement, so for certain Avid storage configurations you will need to add an extra network card.  Please make sure you review the Configuration Guide.