It can entirely depend on who's at the table and what you're fighting. If you're prepared, and things have played out as you've expected, your turn can last as little as 5 seconds, and if everyone else is equally prepared, you could be looking at 2 - 3 minutes per round. But if things get messy, if there are a lot of mobs on the table, if people haven't thought about their next course of action, etc., it can bog down.
My table usually takes around 30-45 minutes per combat, but most of that is me as the GM fumbling the transition between different NPCs.
An hour between turns sounds like there's just something totally broken at that table, though.