All right, here is benchmark score for geekbench 5 : https://browser.geekbench.com/v5/cpu/5560768
fx4300 is 511 for single 1394 for multicore
you got 407 for single, 2130 for multicores
fx8320 is 522 single and 2489 multi
so your single core is underperforming fx4300, but all cores working together (underclocked) are stronger than fx4300.
your cpu is octa, previously you had quad.
that's okay, CPUs with more cores have slower individual cores. 8320 base frequency is 3.5 while 4300 is 3.8. their max frequency is both at 4GHz, so 8320 has more cores but slower ones.
single core tasks are for games, multi-cores are for rendering streaming.