To Separate, or Not to Separate

I have a member DB table that has about 50 fields in it for each record. It holds things like username, password, mailing address, and general site preferences. I'm wondering if I will see any noticeable speed increase if I were to split the 20+ fields that hold preferences (nearly all are single-digit 1/0 fields) out from the other fields that hold general member data, and put them into their own table? Or maybe there's some other good reason for doing this that I'm not aware of? I'd actually prefer to keep it all together, because it's a lot easier to update a single table in MySQL than several if a member makes changes to their account or preferences. What do you think? Monty.