Hi Lance,
In cross platform file server environments where one platform is in heavier use/more demand than the other, it's almost always best to use the native OS and/or File System for the dominant client OS. RAID hardware comments aside, in this case even for basic file server requirements you'd probably be better off using a Mac to share out your direct attached storage.
On the RAID hardware and performance side of things, using a properly tuned network and storage, you would be capable of handling XDCAM EX over GbE. XDCAM goes up to 50Mbits I believe, leaving more than enough bandwidth leftover on a 1024Mbit pipe. XDCAM will put a harder hit on your CPU and RAM compared to PRORES though, and PRORES requires a bit more bandwidth and storage space. The number of physical drives you have will also affect performance and may often yield fewer instances of video than bandwidth calculations alone would predict. As you can see there are many variables that affect the overall performance of any system.
If you'd like to look at a solution designed specifically for sharing video in media production workgroups, then check out our solutions. We have some new configurations available depending on your I/O requirements, including some unique approaches to render farms (depending on the software tools and type of media you're trying to create). We leverage the use of Native File Systems of the Client OS for peak performance and sharing compatibility with our storage server:
http://www.studionetworksolutions.com/video-san.php
-Caspian Brand
Product Specialist
Studio Network Solutions
