Type of 10Gbe nics? RPM rating of hard drive? Make/Model of raid card? Raid 6 with 16 hard drives will cause a bottleneck on the raid card.. Raid cards have major problems getting over the 600mb hurdle with raid 6. If you want more performance consider raid 10 or raid 5. I run raid 10 for my 20 disk VM system but i also replicate to a second 20 disk san both open-e. This ensures i have dual fail over encase of disk loss.