To provide some further clarity as to why we benchmark/review CPUs at 1080p, I did some quick runs with Assassin's Creed: Odyssey - it's heavy on the CPU and GPU. The graphics card used was a 2080 Super, and the CPU was an i7-9700K. All quality settings were set to their highest values.
The same area in the game was looped through a few times, and the minimum, maximum, and average frame rates noted, and then averaged over the loops. The CPU was put into 2 configurations: 8 cores, all at 4.9 GHz, and 4 cores only, all at 3.6 GHz, to represent a 'high end' and a 'budget' CPU. The % difference refers to how much an increase the
[email protected] setup achieves over the
[email protected] setup.
1080p results (min/avg/max)
[email protected] = 31 / 83 / 171
[email protected] = 25 / 56 / 108
%diff = 24% / 48% / 58%
1440p results (min/avg/max)
[email protected] = 31 / 67 / 126
[email protected] = 24 / 56 / 104
%diff = 29% / 20% / 21%
4K results (min/avg/max)
[email protected] = 31 / 45 / 73
[email protected] = 24 / 46 / 72
%diff = 29% / -2% / 1%
Now the minimums here are not 1% Low values, they're absolutely minimums (and they're almost always caused by the CPU and/or platform, rather than the GPU), but other than these figures, note how there is practically no difference between the two CPU configurations at 4K. With 1440p, the gap opens out and at 1080p, it really opens out.
4.9 GHz is 36% faster than 3.6 GHz, so to be achieving a difference of 48% to 58% (average and max) at 1080p clearly shows that halving the core count notably impacts this particular game's performance, just as one would expect putting a high end CPU up against a budget one.
But the point of all of this is to show that at 1080p, in today's game, differences in CPUs are more clearly highlighted, just as they are when using the likes of Cinebench or 7zip.