3 ms·

This isn't actually true. Looking at aveeages will in fact reflect correctly on average frame staleness over a sampling period. A single frame that's 5x too lon

This isn't actually true. Looking at aveeages will in fact reflect correctly on average frame staleness over a sampling period. A single frame that's 5x too long or 4 frames that are 2x too long have the same impact on the average delta of frame staleness on the total sum. Think of it like Little's law in queing theory , it's better to simply just look at different percentiles, like 99 or 99.9th. The average framerate correctly indicates the average staleness.

wtallis 3y ago
> A single frame that's 5x too long or 4 frames that are 2x too long have the same impact on the average delta of frame staleness on the total sum. It's not clear to me: are you saying those two scenarios should be quantified as equally bad? Because it seems pretty obvious to me that the 5x outlier is qualitatively much worse.
- sudosysgen 3y ago
  The fact that the 5x outlier may be qualitatively worse is something that you pin down using percentiles, which is what everyone does, either 1% or 0.1% low. The argument about time-weighted frame staleness is not mathematically valid.
  - Retric 3y ago
    There’s nothing inherently mathematically special about 1% or 0.1%, you can also use 0.0042% or 0.00069% which highlights this kind of extreme outliers more. Benchmarking sites use 1% or 0.1% because they better highlight the commodity PC hardware rather than the games bugs and architecture.
    - sudosysgen 3y ago
      That's not true. You can't use 0.0042% because then you don't have enough frames to be statistically significant without running for a very long time. It's also true that a frame pacing issue that is so rare that it isn't even impacting the 0.1% frame time isn't going to be noticeable, really. These benchmarks are controlled for game bugs and architecture by simply averaging over ~40-50 games, on repeatable loops.

3 ms·

This isn't actually true. Looking at aveeages will in fact reflect correctly on average frame staleness over a sampling period. A single frame that's 5x too lon

by sudosysgen 3y ago

wtallis 3y ago
> A single frame that's 5x too long or 4 frames that are 2x too long have the same impact on the average delta of frame staleness on the total sum. It's not clear to me: are you saying those two scenarios should be quantified as equally bad? Because it seems pretty obvious to me that the 5x outlier is qualitatively much worse.
- sudosysgen 3y ago
  The fact that the 5x outlier may be qualitatively worse is something that you pin down using percentiles, which is what everyone does, either 1% or 0.1% low. The argument about time-weighted frame staleness is not mathematically valid.
  - Retric 3y ago
    There’s nothing inherently mathematically special about 1% or 0.1%, you can also use 0.0042% or 0.00069% which highlights this kind of extreme outliers more. Benchmarking sites use 1% or 0.1% because they better highlight the commodity PC hardware rather than the games bugs and architecture.
    - sudosysgen 3y ago
      That's not true. You can't use 0.0042% because then you don't have enough frames to be statistically significant without running for a very long time. It's also true that a frame pacing issue that is so rare that it isn't even impacting the 0.1% frame time isn't going to be noticeable, really. These benchmarks are controlled for game bugs and architecture by simply averaging over ~40-50 games, on repeatable loops.