4 ms·

Out of curiosity how does one measure the frame rate of the terminal on macOS?

snuxoll 8y ago
Never benchmarked a virtual terminal before, but wouldn’t one basically use a timer and a bunch of unbuffered+blocking writes to stdout to determine how fast the terminal is drawing?
entropie 8y ago
from the link (Prefs > Advanced > Show FPS meter)
- electricslpnsld 8y ago
  That's an iTerm2 specific feature.
- saagarjha 8y ago
  This only works for iTerm, and only when using Metal.
derefr 8y ago
There’s probably some software tool to give you an internal perspective on it, but if you want to “prove” your frame rate for any application, there’s one obvious way: 1. make the app full-screen; 2. make the app constantly vary the screen output as often as it can; 3. capture the HDMI output of your computer with a hardware video capture box[1]; 4. use some scriptable video software to calculate, for the captured video, how many distinct frames (i.e. changes in content from the previous frame) it contains per second, on average.[2] —— [1] you could also substitute a high-speed camera pointed at your monitor (necessary when the limiting factor is monitor refresh rates.) [2] Conveniently, if the capture box emits video in a format with inter-frame compression, you can do the new-frame-counting at a low level, without decompressing the video. You parse through the video stream, discarding the “no change” I-frame chunks, and then count the remaining frame chunks grouped by the start-timecode field cast to seconds. Which is, I assume, what OS file-indexing services do to calculate a video’s FPS, for those that do. This answer is slightly high in the case that you’ve got no-change keyframes in the stream, but it should average out to essentially the same number in any video longer than a few seconds.
tpush 8y ago
There is 'Quartz Debug', a tool in the 'Additional Tools for Xcode' package by Apple, that one can use to display the Frame Rate.

Never benchmarked a virtual terminal before, but wouldn’t one basically use a timer and a bunch of unbuffered+blocking writes to stdout to determine how fast the terminal is drawing?

entropie 8y ago

from the link (Prefs > Advanced > Show FPS meter)

electricslpnsld 8y ago
That's an iTerm2 specific feature.
saagarjha 8y ago
This only works for iTerm, and only when using Metal.

derefr 8y ago

There’s probably some software tool to give you an internal perspective on it, but if you want to “prove” your frame rate for any application, there’s one obvious way: 1. make the app full-screen; 2. make the app constantly vary the screen output as often as it can; 3. capture the HDMI output of your computer with a hardware video capture box[1]; 4. use some scriptable video software to calculate, for the captured video, how many distinct frames (i.e. changes in content from the previous frame) it contains per second, on average.[2] —— [1] you could also substitute a high-speed camera pointed at your monitor (necessary when the limiting factor is monitor refresh rates.) [2] Conveniently, if the capture box emits video in a format with inter-frame compression, you can do the new-frame-counting at a low level, without decompressing the video. You parse through the video stream, discarding the “no change” I-frame chunks, and then count the remaining frame chunks grouped by the start-timecode field cast to seconds. Which is, I assume, what OS file-indexing services do to calculate a video’s FPS, for those that do. This answer is slightly high in the case that you’ve got no-change keyframes in the stream, but it should average out to essentially the same number in any video longer than a few seconds.

tpush 8y ago

There is 'Quartz Debug', a tool in the 'Additional Tools for Xcode' package by Apple, that one can use to display the Frame Rate.