Don't think you asked me to prove it. you asked how much it's improved and I didn't go quiet, I said I didn't have an exact number but it's substantial, atleast 10% just going by what I remember from testing out an older version vs a newer one. And again we know that RT is now hardware accelerated, it goes without saying that it's faster.
This is not some mysterious engine that you can't touch, this had been available in early access for ages, it's easy to see how much heavier it is on GPU than CPU. Why did they focus on graphics and not performance? Because devs are already aware you could improve it with optimization, it's far more important to show just how good it can look and that it's possible to put a product out with it. Proving that you can have raytraced GI,Shadows and reflections in a city of this quality is important, A dev isn't going to worry about a tech demo dipping to 24fps when all that is happening they understand that fixing these things are small in comparison to getting the graphics to this level.
I've got no reason to doubt them when they say there is tons of CPU headroom, A lie about that would only hurt them since this is coming to pc soon enough and we have already seen how it works for ourselves.
This isn't some game company desperate to make their day one sales as high as possible.
I know for certain that combat in many games is extremely cheap compared to the graphics and crowd simulation of this. Not saying that it works with absolutely anything. but, most games don't require more than what you saw in the shooting segment. If you aren't making something like the zombie system in days gone combat is usually very cheap on the CPU, Demons souls ran on ps3, a little headroom is often all you need.