Mining rig with most hashrate

[YoungPadawan61]

Hay frends 

I have an budget of 50.000€ and want to build a rig with the best cards which gives me the highest hashrates(electric cost is on second line so hashrate is more important for me) i looked some around and build also a rig with 4 rtx3090 asus rog strix 24gb cards. Now i would know some advise what to buy also motherboard, cpu and power supply.