yeah thats true,
but im planning to get a rtx 3090 and run 3, 4k monitors for gaming so i thought the 5900x would be better due to the 3 screens, if that classed as multitasking while gaming.
i have 3 4k screens now but my 2080 and 2700x cpu struggle to get 50fps with changes to settings so im hoping the new cpu and 3090 will give me the well atlest 60fps
Those screens, and the resolution, and all of that display related stuff, literally have NOTHING to do with the CPU performance, at all, ever, so long as the graphics card is able to keep up with it's part of the job. Or at least, it has VERY little to do with it, in a worst case scenario.
It wouldn't matter if you had five 4k screens, or just one, the load on the CPU would mostly be the same either way. It's the graphics card that is going to get severely taxed by the high resolution and the number of displays. Now, the refresh rate is relevant, or might be, to the CPU, because you generally want a CPU that is capable enough to provide pretty close to the same frames per second as what the refresh rate is. Having a display with G-sync or Freesync reduces or eliminates some of this concern to some degree, but even so, you STILL kind of want to land in that zone that's relatively in the ballpark in terms of at least being within shouting distance of your refresh rate if not exceeding it, and we're talking minimum FPS, not average or peak, because minimums are where problems occur.
But, the refresh rate has nothing to do really, not directly anyhow, with CPU performance. It doesn't PUT a load on the CPU, you just want a CPU that is capable enough to be well matched for whatever the refresh rate of any displays being actively gamed on is.
Honestly the 5600x could manage 60fps without any problem on most games, IF the graphics card were capable enough to ensure that GX related performance isn't what is slowing things down and right now I'm pretty sure it IS the biggest culprit in that regard. If you get ANY Ryzen 5000 series CPU that's been released so far, and an RTX 3090, you should be well on your way to where you want to be and beyond, and if you're not, well, there's nothing else out there that's better that could get you there anyhow, so it wouldn't really matter. You'd already be doing about the best you could do. Consider, one year ago the 9900k was the best gaming CPU money could buy, and the 5600x outperforms it in most titles and most applications.
So do the higher end 5000 series models. So, anything along those lines is doing pretty well and for a multiple 4k setup graphics is going to absolutely be where any tremendous bottlenecks are found unless you're trying to get 144fps or higher. Then the CPU might become a factor, but if so, there isn't anything better you could opt for anyway, so (shrug).......