In real life you have O/S, applications and multitasking to contend for.

According to CPUBenhmark below are the scores.

i5-520m 2.4 gHz.  Score: 1730

i7-8400k 3.7gHz  Score: 13,778

i7-12700K Score: 34,668

If what you say is correct, try to run Windows 10 with i5-520m.

I have been in computing since the first Intel 8088 chip.  I have all my old CPUs framed starting from 8088, 80286, 386, 486, Pentium 90, Pentium 2, and more  all the way to the 7th Gen Intel.  I have switched to ARM based M1 CPU in Apple.  All my home computers now are Apple M1 CPU baed.