Forza Horizon 4 - Vsync Enabled Test
In contrast to the prior test, here's results with Vsync enabled.
Just a few too many dropped frames here.
-as an afterthought to this, as frame-rate tends to stay steady during moments of stutter (what you see here is not a capture or encode stutter, it was in game), dropped frames probably isn't correct and it's more likely a frame draw delay/latency issue. Easy way to test would just be fire it back up, enable Vsync again, and compare frame latency vs Vsync off, but I'm not that concerned with it now that I seem to have it sorted out.
Or it's discarding one frame too many at times while trying to maintain a locked rate (which shouldn't happen), and being a faster moving game it's more apparent.
Doesn't seem to be any bottle-necking on my system side.
Really this game tends to make pretty even work of all system resources with nothing being pushed too hard at any given moment, which is rather impressive considering it's still new-ish, and the resolution and settings I'm pushing it at.