the Test complete is essentially functional testing tool not performance testing tool.
But TC can monitor performance of the computer it running test on.
More please refer this
Depends what you mean by "performance testing".
People have all sorts of different ideas of what this encompasses.
If you're talking multiple, concurrent, users hitting a centralised server, then TC is probably not the tool to use. (It can be done, but it's not really designed for it and the license costs go up quickly for multiple users. Dedicated performance tools are more suited to this.)
If it's the above, but only for a single user, just add some timers around the response areas. Then it's doable.
If it's things like CPU and memory profiling during a run, then TC has performance counters built in for that.
