Fasauceome

I'm assuming OP already owns these components

The only Zen based Athlon CPUs are the Athlon 200GE, 220GE, 240GE, and 3000G

non-Zen Athlon CPUs lose support when updating the BIOS.

what CPU were you previously using? does it work with the 3600 or that CPU?

bios updates can fail spontaneously. what motherboard?

I had this happen and said screw it to see what happens, turns out the thermals are fine

I left room in the budget in case parts were more expensive with shipping/taxes for OP also future proof isn't real

PCPartPicker Part List Type Item Price CPU AMD Ryzen 3 3300X 3.8 GHz Quad-Core Processor €131.90 @ Alternate Motherboard MSI B450-A PRO MAX ATX AM4 Motherboard €71.90 @ Amazon Deutschland Memory Team T-FORCE DARK Za 16 GB (2 x 8 GB) DDR4-3600 CL18 Memory €63.55 @ Amazon Deutschland Storage Kingston A2000 1 TB M.2-2280 NVME Solid State Drive

it's so blurry, is this a scratch?

you won't be able to combine the graphics power of those cards.

Seems like you need a parts list recommendation, you should post a topic with your country and budget and ask for full suggestions, instead of a topic for each component.

The i5-10400 is worse for gaming than the ryzen 5 3600 unless combined with a Z490 motherboard and some DDR4 3200. The i7, on the other hand, is faster. Not to mention: The generational leap was non-existent so the clock speed wins out here, and 2 physical cores vs 6 virtual cores isn't a very big difference at all.

A Z490 series motherboard is required to overclock a 10th gen intel CPU, and a CPU with a K in the name is required for overclocking. Intel reserves overclocking for the most expensive hardware.

100% GPU usage at 1080p? What happens when you change the settings a bit?

Not recommended but it is capable of running the 1600 in order to update the BIOS. There are just concerns over stability when gaming. Well if the performance is to your standards then the upgrade wouldn't be necessary