Frame Rate and Frame Time
FPS in milliseconds
Also known as: FPS · Frame time · Frame budget · 60 fps 16.6 ms · Milliseconds per frame · Frame rate target
Definition
Frame rate is how many images a game draws each second, in frames per second, and frame time is the time one image takes in milliseconds. They are linked: frame time equals 1000 divided by fps, so 30 fps is 33.3 ms, 60 fps is 16.6 ms, 90 fps is 11.1 ms and 120 fps is 8.3 ms. Performance work uses frame time, because the savings add up in milliseconds, and a frame budget is the time each system, such as rendering and gameplay, is allowed to take.
In production
Aim for a stable frame rate rather than a high peak, since uneven frame times feel like stutter even at a good average. Fix the target for your platform, then split the budget between CPU and GPU work. As an artist, think in milliseconds: an expensive material or particle effect might cost one or two ms per frame, which is a large share of a 16.6 ms budget.
Tools that use Frame Rate and Frame Time
See also
CPU Bound vs GPU Bound
Which processor limits the frame rate
Profiling
Measure before you optimize
Draw Call
GPU rendering command
Overdraw
Redrawing same pixels
VR Performance Budget
Why VR needs higher frame rates and simpler art
Mobile Optimization
Art budgets for phones and tablets
Animation Frame Rates (24, 30, 60 fps)
Which frame rate to animate and export at