RAC4 (pentium4) test:

sys@TEST1> declare
  2   i number;
  3   j number;
  4   a number;
  5  begin
  6   for i in 1..100000 loop
  7     a :=0;
  8     for j in 1..10000 loop
  9       a := a +1;
 10     end loop;
 11   end loop;
 12  end;
 13  /

spool off

PL/SQL procedure successfully completed.

Elapsed: 00:01:24.63


-------------------
QuadCore test:

set timing on
declare
 i number;
 j number;
 a number;
begin
 for i in 1..100000 loop
   a :=0;
   for j in 1..10000 loop
     a := a +1;
   end loop;
 end loop;
end;
/


PL/SQL procedure successfully completed.

Elapsed: 00:01:04.18