I upgraded from a GTX 1660 to an RTX 3080 because I found it cheaper than a 3070 Ti. My system has an Intel i9-10900, 32GB of DDR4-3000 memory, an EVGA 750W Gold power supply, and two 1080p 144Hz MSI monitors. I mainly play Rust and previously averaged around 60–80 FPS. Could the RTX 3080 be bottlenecked by my CPU, and are there any BIOS or in-game settings I should change to improve performance?
3 Answers
The i9-10900 is still a capable gaming CPU, and there is no special BIOS setting that will dramatically change performance. Since it is a non-K model, traditional multiplier overclocking is not really an option; make sure its normal boost behavior is working, temperatures are under control, and XMP is enabled for the memory. You can also use a frame-rate cap if you prefer steadier frame times.
Before changing anything, verify the full hardware list. A B550 motherboard is designed for AMD processors and cannot run an Intel i9-10900, so that model name may be a typo. Also, at 1080p, Rust is more likely to run into a CPU or game-engine limitation than fully use an RTX 3080. Moving to a newer platform could help, but it would normally require a new motherboard and possibly new memory; there is no major drop-in CPU upgrade for the same Intel socket that is likely to transform Rust performance.
The bottleneck depends on which component is actually at full usage. With an uncapped frame rate, if the GPU is near 99% usage, it is doing its job and the system is GPU-limited. If the GPU usage stays low while one or more CPU cores are fully loaded, Rust is probably CPU-limited. Rust is particularly demanding on the processor, so an RTX 3080 will not automatically guarantee very high FPS, especially at 1080p.
Would there be an Intel processor upgrade that works with my current socket? I was hoping to avoid replacing the whole platform, although I may start upgrading parts gradually.

Mine is the non-K version, so I do not think I can meaningfully overclock it.