Overhead with ipchains

[Joel Hammer]

I use ipchains on my firewall.
I have a lot of rules in it, some no longer needed. 
Is there any performance hit to your transfer speed (I am on a cable modem)
with ipchains due to the number of defined rules?
Along the same lines, is it significantly more efficient to have one rule
blocking several ports rather than several rules, each blocking one port?
Any insight appreciated.

Joel