Originally Posted by
Cilraaz
Is your WoW set to DirectX 11 mode? If so, Xfire is still incompatible with it. Personally, I use Ustream for live streaming ever since the DX11 issues with Xfire and fraps for local capture. I believe Ustream has a local capture mode, as well.
[edit: I take that back. Apparently, I haven't been following Xfire in the past few months. They added experimental support in v1.140, back in October. I'd still swap back to DX9 (if you're on DX11 in WoW) and see if you still have the performance degradation.]