Topic: Very poor database performance with SSL enabled

I'm new to Ruby/Rails and am trying to set up a server for deployment. I've chosen to use PostgreSQL with Apache + mod_proxy + a Mongrel cluster. The entire app needs to run on SSL, i.e. all requests are redirected to https. (I have this working both with the SslRequirement plugin, and simply using Apache to make sure all requests are redirected to https.)

The problem I have is that as soon as I enable SSL, the database access slows down dramatically - it takes (just on a wall clock count) about 10 seconds, sometimes more, to add a simple record to the database! (This is using a standard form to enter some model data.) If I turn SSL off, the exact same action takes around 1 second. I guess I must have misconfigured something but am at a loss as to what ...

I'd be truly grateful if anyone has some pointers for me, even just advice on what to Google for (since my searches so far haven't turned up anything useful) - any articles, or suggestions of where to start looking for the problem.

If it would be useful to post any of my configuration files here please let me know.

Thanks for any help