Surely the RAM must make some kind of difference, right?
Also to this point, I'd also like to know what CPU is the cheapest that will give me the same performance as a 9800x3D then in 4k with a 5090 if that is the case.
I'm always told there's no point in even checking. It'd be nice for one person to do the tests to confirm this.
These tests are pointless. 1080p doesn't prove anything. People buying high end CPU-s are using them on 1440p systems at least. New standard for testing should be 2k+4k results od UE5 games with multitasking while game is on. That's how people are actually using their PCs. These isolated tests prove nothing. Also,stop advertising 8 core CPUs,they will be bare minimum in few years. 9950x3d is THE cpu to test if you are comparing flagships.
What you mentioned ends up reducing the impact of RAM and CPU quite significantly, not increasing.
The reason why high end CPUs are generally tested in 1080p, is that almost all games at 4k would be GPU limited, not CPU. So you end up actually using less CPU, as it's spending more time just waiting for the gpu to finish drawing the frame before it gets called back to do work again.
Hardware Unboxed has tested and compared the performance of the Arrow Lake Core Ultra 9 285K and the Ryzen 7 9800X3D. Even after the performance enhancing updates and with the 200S Boost overclocking, the Core Ultra 9 285K is still no match for the Ryzen 7 9800X3D.