Here at TR, we've long considered multi-GPU rendering something of a false grail for graphics-performance scaling. Potent multi-GPU cards like AMD's Radeon HD 7990 and R9 295 X2 have tended to deliver world-beating average frame rates in our testing, but our Inside the Second frame-time measures usually put a big fat asterisk next to those cards' numbers. That's because issues with consistent frame delivery have often made those CrossFire-on-a-stick cards feel much less smooth in practice than their astronomical frame rates might suggest.
The Radeon R9 295 X2
To get around this problem, Radeons include frame-pacing algorithms in their drivers to make sure that inter-GPU timing issues don't mess with smooth frame delivery too much. At least in the red team's case, that technology apparently wasn't available in DirectX 12 titles—at least until now. AMD tapped some guy from its performance-testing department to explain the technology and its benefits in an informative, concise video that's well worth a watch.
We haven't verified these results for ourselves yet—doing so would require use of an FCAT rig that I don't have set up here. Still, given our history, we're inclined to trust that AMD guy in the video above. DirectX 12 frame pacing for Radeons is available in the Radeon Software 16.10.1 release that hit the interwebs yesterday. If you've got multiple Radeons churning out frames in next-generation titles, you'll most definitely want to install that update post-haste.