Thanks, but im not from the US so i never buy things from Amazon since shipping's like 70$ for me. And i can use my current 16gb kit which is clocked at 2400mhz but apparently i can overclock it to 4200mhz in the BIOs. Yeah ik it shouldnt, but it does, i get frequent freezes and fps drops to like 2fps for a millisecond and that makes a game like R6S unplayable for me. And i think its the CPU's fault since its at 100% all the time.
It was an example
Overclocking 2400mhz RAM to 4200mhz is highly unlikely at least without a God tier motherboard and specific modules, being you have an I5-7500 and 1050 TI I am going to expect you have neither the motherboard or modules that are that high quality. Moving to Ryzen and expecting to overclock is also a big? If you have early DDR4 modules designed around Intel then even hitting and staying stable around 3000mhz is going to be a shot in the dark and most likely not happening.
Fortnite- This game primarily uses 2 cores the Fps difference between a Quad or more is minimal.
Example
Rainbow 6 should work fine on a Quad-core, it's designed around load balancing and if your seeing 100% load for long durations you have an issue other than the CPU can't handle the game.
What I suggest.
Check your thermals under load
Check what is running while you game
Check for Viruses and Malware
Update and Purge your BIOS
Make sure you have the latest drivers
Make sure both games are updated
Make sure any AV you have isn't interfering or blocked processes and see to it that you have the option of Gaming mode enabled.
After all of that run the benchmarking tool for each game and see what happens.