i7-4790k is the highest drop-in replacement for the board after you do a bios update first.

That being said, it’s a pure waste of money. Don’t do it.

Also, to answer the question from the title: The highest Intel CPU that can pair with a GTX 660 Ti is the Intel Xeon Platinum 8480+. And on the mainstream-desktop it would be the Intel Core i9-14900K.

Unless you’re running a lot of memory (think more than 64gb) you won’t have any trouble below DDR5-6000, most Intel CPUs run up to DDR5-7000 just fine.

Make sure you’re running the latest BIOS version, they do improve compatibility and stability for fast memory from time to time.

If the need is gaming, anything above an i5 is icing on the cake. Yes, it’s a little faster. But not noticeably so.