This, absolutely this!
Do NOT rely on any "bottleneck calculators" because they are complete garbage, and the term "bottleneck" when it comes to computing has been misused to the point of uselessness.
There is no "perfect" match of CPU to GPU. No such thing.
It's all a matter of:
- monitor refresh rate
- monitor resolution
- if your monitor has FreeSync, GSync, or neither
- what specific games you're playing.
You have a 1920x1200 monitor. So, you have 11% more pixels than a 1920x1080 monitor. Your 1660 is still pretty good for gaming at 60Hz.
For some games, the GPU might be the weak link, for others, the CPU might be the weak link.
Exactly what performance are you looking for? Average better than 60fps? Absolutely NEVER dipping below 60fps? Are high/ultra details required, or will you turn them down some.
In what way is your current GPU holding you back?