That CPU isn't really made for "everyday computing" its more for a server type system. Also being an Engineering Sample it could have come from anywhere along the line of testing and distribution, maybe even early in the line, so that could very well explain some issues you are having.
The 990x is ancient compared to this Xeon, I can't imagine it performing nearly as well overall. But like I said, being an Engineering Sample any number of things could be causing your issues.