What kinds of games do you play?
If you play fast action games or at high resolutions, then a 3060 gpu upgrade might be good.
What is the make/model of your current psu?
Your current psu is likely sufficient if it is of good quality.
Otoh, if you are cpu limited, a i7-4790K upgrade is ok only if you play multiplayer games with many participants.
For games such as sims,mmo and strategy the single thread performance is all important, and that does not change much going to i7-4790K.
If you have not yet done so, you can get some 25% more compute power by overclocking your 4690K.
Try this simple test:
Run YOUR games, but lower your resolution and eye candy.
This makes the graphics card loaf a bit.
If your FPS increases, it indicates that your cpu is strong enough to drive a better graphics configuration.
If your FPS stays the same, you are likely more cpu limited and a new cpu is in order.
Run the cpu-Z bench test and look at the single thread rating.
It should be something like 490.
Here are some other scores:
Best CPU performance - 64-bit - November 2024
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