That's retiring in style, sir! Congratulations and enjoy!
So far I think there's something smoother or more fluid during head movement in TrackIR with VSync enabled. I can't quantify it; my fps is in the low 100s with Enhanced Sync enabled (which doesn't seem right, as I though you'd said it would limit to monitor's refresh rate). I'll keep trying it both ways before I make a final judgement though...
When ES is enabled, the GPU runs unhindered from the monitor's RR so the GPU will run as fast as it can rendering graphics frames but the frame buffers will only flip fully finished frames in sequence to the monitor at the monitor's RR thus no screen tearing....as long as the GPU can maintain FPS above the monitor's RR. This is accomplished by how ES uses the 3rd frame buffer to allow the GPU to render as fast as it can but only send fully finished graphics frames in sequence to the monitor at the monitor's native (or manually set) RR to eliminate screen tearing.
Most FPS monitoring softwares measure FPS off the GPU side of the graphics pipeline (which doesn't pick up the flip rate between the frame buffer to monitor) so the AHIII FPS counter is showing the actual GPU rendering rate of frames being sent into the frame buffer(s), not the actual flip rate of frames being sent from the frame buffers to the monitor as this side is intiated from the monitor's signaling itself.......
As an aside, this is why you've heard\read that it doesn't matter what you see in the AHIII FPS counter, the graphics frames are ALWAYS being displayed at the MONITOR'S RR and NOT at the FPS rate you see in game as long as VSync is turned off....this is the rate you actually are "seeing" on screen and the only way to actually speed this rate up is to increase the monitor's RR. Only when VSync is on is when the GPU rendering rate in FPS is tied to the monitor's RR. This linking of rendering to monitor signalling is where you're seeing the "smoothness" in motion coming from. Think of this in terms of signal timing instead of just signal rate.....thus you will now understand the importance of frametimes in ms (milliseconds) in addition to just framerate in FPS. I would venture to say that IMHO frametime is slightly more important to focus on nowadays than framerate is when it comes to total onscreen graphics performance as most of todays graphics cards, regardless of whether it's a Nvidia or AMD graphics card, can generally meet\exceed 60 FPS (or 60Hz) under a decently high graphics rendering load so the impetus should be on how SMOOTH does the card perform at speed..........
This aspect of a graphics pipeline's operation is no different from just using VSync off in relation to monitor's RR, which is what ES is trying to use to optimize (read reduce here) control input lag and at the same time eliminate the screen tearing that usually results from the GPU running unsync'd from the monitor's RR........
Hope this helps you out.
PS--IMHO, the main reason for upping graphics power today is to increase monitor resolution and\or RR.....or new tech such as VR which requires increased graphics rendering capability....or to just max out graphics rendering settings within your game. So if a user isn't gonna do these things (upgrade monitor, go to VR or max out graphics rendering) and are using at least a 3rd gen graphics card or newer then save yourselves some money as far as graphics cards are concerned....
I have a video that I recorded of my current box running AHIII on my spare XFX Radeon R9 290X graphics card (3rd gen) at stock clocks using the exact same graphics settings I used w\ my Sapphire Radeon R9 FuryX graphics card using the exact same driver and driver settings (was in transition to my current setup at the time) showing that this 290X was more than capable of running the game in excess of 60 FPS consistently (never dropped below 78 FPS) w\o issue.
