Performance on 64 bit Linux vs 32 Bit

[ram]

I have been using MailScanner on 32 bit centos for quiet some time now
on the ~25 Antispam servers which we have ( MailScanner + Postfix +
Spamassassin + Custom spam engine ) 

Now I was trying to evaluate  64 bit Linux. Would Mailscanner perform
any better on 64 bit linux. I personally have no first-hand experience
of 64 bit linux, I thought of doing some research before I upgrade 




Thanks
Ram