Photographic proof that my microstutter math is correct. Long camera exposure (1second) while the mouse arrow moves past. For practical purposes, I had to limit to a mouse movement of 960 pixels/second (approximate, via chasing a TestUFO motion object with my hand on a nearby black window).
5 microstutter per second at 125Hz poll = gapping every 25 positions = (120 refresh / (125 MOD 120))
20 microstutter per second at 500Hz poll = gapping every 6 positions = (120 refresh / (500 MOD 120))
Photographic proof of my microstutter math!
Sometimes the timing of the microstutters aliases back and forth (e.g. gapping every 24 to 26 positions and some occasional outliers, rather than exactly 25 every time) due to other timing imprecisions, but the microstutter definitely averages these numbers.
And I can definitively confirm it is easier to see in real life than in these photos, for certain cases (120fps VSYNC ON, or GSYNC, or ultrahigh framerate VSYNC OFF where framerate is high enough to avoid big harmonics), for the situation of left/right turning in FPS games on recent cards in older engines (Source, etc) during 120Hz+strobing (LightBoost)
than in this photographic capture. It definitely isn't detectable at 60Hz. And hard to see regular 120Hz. But once you do strobed(LightBoosted)
120Hz, the 500Hz vs 1000Hz pollrate actually becomes visually noticeable especially at ~1920pixels/second. Precision controlled refresh timings (e.g. GSYNC) can also make mouse Hz harmonics visible. Mouse 500Hz vs 1000Hz is confirmed (on my system) the biggest source of microstutters during solo gaming Source Engine double-buffered VSYNC ON 120fps on a GeForce GTX 600series/700series/Titan on a strobed 120Hz monitor
. Some of us like VSYNC ON double buffered to get perfect stutterfree motion in older engines during our solo games when lag isn't important.
We have finally reached a technological point where 2000Hz mice will actually soon make a human visible difference, especially when we go to strobed 240Hz (OLED rolling scan). At that point, USB timing jitter is a weak link, but there are workarounds with special USB techniques to get that required precision, and bypassing USB hubs.TL;DR: Consider using a 1000Hz mouse poll rate if using a 120Hz+ monitor at high frame rates, especially if using strobing (LightBoost) or GSYNC.