Question is B550 worth it if i change from B450?

Putra23

Prominent
Apr 1, 2023
33
6
545
current board and spec is
msi B450-A PRO MAX
ryzen 5 5600
16GB (2x8gb)
Rx 6600

just a dilemma, i want upgrade my m.2 from klevv Crass C730 512GB to MP44L (yes gen4) since gen 3 and 4 the price almost same at 1TB .
but the problem my current board only have 1 slot m.2 and idk worth it to B550 or better get pcie extention for ssd? and the board only avaliable pcie 2.0 x1 and x4