speed on Postgresql compared to Mysql

Hi,

Talking about insert, I know Mysql is fast than Postgresql.

I've made the following test :

40'000 insert (accouting context) using Perl and dbd :

Postgresql :
  text       :  4 min 53 s
  varchar :  4 min 49 s
  char      :  4 min 49 s

Mysql :
  text       : 0 min 29 s
  varchar : 0 min 29 s
  char      : 0 min 29 s

So we can see Mysql is about 10 times fast.

Also we used Postgresql for Radius (authentication) et we have to make 3
vacuum per day otherwise the first server is overload and the user go to the
backup server.

Is it normal or my Postgresql is not well configured ?

Thanks in advance.