Since that MoBo has mere 4 main phase VRM and also will reduce CPU performance, both on high workload and in gaming as well.
B650 MoBo roundup (where that MoBo is also listed):
https://www.techspot.com/review/2633-amd-b650-motherboards/
this is not too accurate :
they both have the exact same configuration of VRM ragarding power phases .
they are both 4 phase motherboards using doublers making them
"fake" 8 phases dedicated to VCORE (which is better than just plain 4 phases of course) .
both are 2x4+2+1 designs:
so if you want to call one of them 8 power phase design you have to call the other one 8 phase design also .
however the main difference between them and the reason why one fails the thermal tests and
the other does not is the quality of their mosfets :
asrock uses higher quality and higher efficiency Vishay SiC654 (50A) mosfets
asus is using cheap garbage Onsemi 4C10B (46A) :
while on paper they might look almost the same the main difference is their efficiency under heavy load -
with less demanding processors they are both fine ,
but when we want to push lets say 20A of current through each mosfet and the voltage of our cpu is set to
lets say 1,3V than the mosfets need to handle 208w of power or 160A combined
(20A for each of the 8 mosfets) :
the problem with cheap onsemi mosfets is that their peak efficiency is at 11-12A of current ,
anything more and it drops significantly which means more residual heat .
at 20A this mosfets would create around 50w of residual heat combined
while Vishay SiC654 keeps its effciency at 91-92% even at 20A for each mosfet
and it would create only roughly half of that residual heat under such conditions .
thats why despite technically having the same power phase design cheap asus board fails
studio tests of hardware unboxed when paired with overclocked 7950x for example -
because that cpu can be really power hungry while running stress tests:
with PBO enabled it needs almost 250w of power and that is why (in combination with weak heatsinks)
asus overheats to 100+ C° and fails while asrock board does not ...
"it is not because one is 4 phase and the other is 8 phase" -
they are both 2x4 boards .