I recently upgraded to a 4090 and hear all the time about how the cpu could be limiting performance a bit with this card. I’ve already got a z690 with a 13700k. I play in 3440x1440 on an alienware OLED. Just curious if it would really make any difference to get either of those for gaming. I know 7800X3d would be a bit better but not feeling as anxious to get a new board for that.
Its not just the cpu, you will also need to change motherboards and ram for the very best cpu performance. Gpu is a standalone device in graphics performance, but cpu performance comes from a combination of ram and cpu and motherboard and so all 3 needs to be the fastest for you to get the fastest cpu performance. Currently the fastest intel cpu performance you can get is by using a combo of 14900k cpu, gskill 8200mhz ddr5 ram and asus apex encore z790 motherboard. Fastest performance is gotten only with the 8200mhz ram, but only the apex encore motherboard is fast enough to support such a high speed ram.
Fastest amd cpu performance is from using a combo of 7800x3d cpu, asus x670e motherboard with 2 ram slots, and 6400mhz cl30 ddr5 ram.