"n% faster/slower" is misleading

Suppose you wanted to promote an upgrade from an RTX 3080 card to the RTX 5080. To do this you could say:

"According to the PassMark G3D score, the RTX 5080 is 44% faster than the RTX 3080."

However, suppose that instead you wanted to disincentivize the upgrade. In that case you could say:

"According to the PassMark G3D score, the RTX 3080 is only 30.6% slower than the RTX 5080."

Well, that can't be right, can it? At least one of those numbers must be incorrect, doesn't it?

Except that both sentences are correct and accurate!

And that's the ambiguity and confusion between "n% faster" and "n% slower". The problem is in the direction we are comparing, in other words, in which direction we are calculating the ratio between the two scores.

The RTX 3080 has a G3D score of 25130.

The RTX 5080 has a G3D score of 36217.

If we are comparing how much faster the latter is to the former, in other words, how much larger the latter score is than the former score, we do it like:

36217 / 25130 = 1.44118  →  44.1 % more (than 1.0)

However, if we are comparing how much slower the former is than the latter, we would do it like:

25130 / 36217 = 0.693873  →  30.6 % less (than 1.0)

So both statements are actually correct, even though they show completely different percentages.

The fundamental problem is that this kind of comparison is mixing ratios with subtractions, which leads to uneven results depending on which direction we are making the comparison. When only one of the ratios is presented (as is most usual), this can skew the perspective of how much the performance improvement actually is.

A more unambiguous and accurate comparison would be to simply give the factor. In other words:

"According to the G3D score, the speed factor between the two cards is 1.44."

However, this is a bit confusing and not very practical (and could also be incorrectly used in comparisons), so an even better comparison between the two would be to just use example frame rates. For example:

"A game that runs at 60 FPS on the RTX 3080 will run at about 86 FPS on the RTX 5080."

This doesn't suffer from the problem of which way you are doing the comparison because the numbers don't change if you do the comparison in the other direction:

"A game that runs at 86 FPS on the RTX 5080 will run at about 60 FPS on the RTX 3080."