[jblow]

> if you aren't precise to the millisecond things will jump around

It is correct that precision is very important here, but, a millisecond is way too coarse: at 120fps, a millisecond is 1/8 of the frame time, and you'd get horrible jitter.

[hwillis]

Ehh. The framerate doesn't actually matter that much, because in the end the actual pixel changes color at the same rate regardless of FPS. No shader is periodic at 120 Hz; they're very rarely periodic at even 10 Hz.

10 Hz is already a slow strobe light; 1 ms deltas means that each flash is within ~1% of the correct color.

If you're doing something like raymarching in the pixel shader, then you might want sub-millisecond resolution. In 99% of normal shaders, I don't think so. That kind of precision comes into play more with moving objects, where a tiny time delta can mean the difference between a pixel being completely lit or completely dark. Even then though, bad time resolution is just as likely to manifest as motion blur or something.