Development mode Mongrel slower than WEBrick?

I just installed Mongrel for my prototype rails application (running
in development mode). I was surprised to see that page accesses to my
application are now noticeably slower (e.g. browser load times of 4s
instead of 2s for one very large and complicated page with lots of
data). For mongrel, the completed line for this request often looks

Completed in 2.34842 (0 reqs/sec) | Rendering: 1.15833 (49%) | DB:
1.17297 (49%) | 200 OK

while for WEBrick it is more commonly:

Completed in 1.12065 (0 reqs/sec) | Rendering: 0.47532 (42%) | DB:
0.59432 (53%) | 200 OK

Is this kind of thing to be expected for development mode? I've read
that Mongrel is faster than WEBrick, which is why I was surprised.
Perhaps it is only faster in production mode, or after some tuning?


p.s. I'm running under RedHat Enterprise Linux, which I see someone
else had performance issues with, although I don't think they noticed
a difference based on which web server was used. I think I'm running
the latest versions of everything -- ruby 1.8.5, rails 1.2.2, mongrel

I think I have just found the problem. Unlike WEBrick, Mongrel
appears to echo to the console most of the output going to the
development log, which in my case has hundreds of SQL statements. I
found that if I start mongrel with:

    script/server >/dev/null

(so that the output no longer goes to the console) the performance
issue I was having goes away. (The browser load time is now back to
about 2s.)