I recently purchased a second-hand M1 Pro mbp14, and when running heavy tasks, its performance is ridiculously poor(several cpu-cores are not engaged). Then I tried to run Geekbench 6, the multi-core score is only one-fourth of a normal M1 Pro, and single-core performance is also significantly below normal values(not all cores working when running geekbench 6). The hardware was tested by the Apple Store and no faults were found, and the system was just restored. So, what could be the issue with my Mac?

I checked that low power mode is off, and I kept charging when running tasks.

Its my Geekbench6 test result：https://browser.geekbench.com/v6/cpu/5736206
[![enter image description here][1]][1]
and its the CPU usage when running geekbench 6
[![enter image description here][2]][2]
[![enter image description here][3]][3]


  [1]: https://i.sstatic.net/M6OcxRNp.png
  [2]: https://i.sstatic.net/XBgrtacg.png
  [3]: https://i.sstatic.net/b0tpt8Ur.png