Well, it depends a lot on how you are implementing your tests, what type of application you're testing, etc. There are some default timeouts built into your TestComplete project. One, under Properties -> Playback has an "auto-wait timeout" which defaults to 10 seconds. The other, under Open Applications -> Web Applications has a page wait timeout of 60 seconds. So, it is possible that, if you are testing a web page and you need to wait for the page to load to go on to the next step, that you could have an extended time of waiting before it returns.
Additionally, if you are using WaitNNN methods or FindChild methods, those could have wait times and processing times as well...
ALSO... each operation in a keyword test that interacts with an onscreen object has an "auto-wait timeout" setting that could over-ride the project default.
and I'm sure there are other factors...
so... if you could share a bit more about what you are doing within TestComplete, there may be some ways of tweaking your tests to run faster.