Test results from my ~13 year old AMD Athlon 3500+, compiled and run from the FPC IDE
■ Free Pascal IDE Version 1.0.12 [2015/11/16]
■ Compiler Version 3.0.0
■ GDB Version GDB 7.4
■ Using configuration files from: D:\speed\
Running "d:\speed\project1.exe "
FILL TEST: [10000000 items]
Records: 0,248648573253774 s
Classes: 2,0375213753895 s
Pointers: 0,9052851958167 s
QUICKSORT TEST: [10000000 items]
Records: 2,58236324632539 s
Classes: 12,3440482267842 s
Pointers: 9,90768453970034 s
FREE MEM TEST: [10000000 items]
Records: 0,155206947245678 s
Classes: 5,768513388735 s
Pointers: 4,44650447871946 s
The majority of time for the Class FILL test is obviously used up by creating the Classes, not by setting the variables. Of note is further that Class variables are automatically initialised with zero on Create, which is not the case for standard records.
Anyway, I am not sure whether anyone would use such atomic Classes in real life.