Hi Azeddin,
> Can I use Testcomplete 9 or 10 for performance testing?.
I would like to ask you to explain what you need with more details.
You can use TestComplete to measure performance from the end-user point of view. E.g. you can measure how much time does it take from the moment when user pressed the Save button and until the confirmation message is displayed on the screen.
Using the Network Testing TestComplete's functionality (
http://support.smartbear.com/viewarticle/62722/ and
http://support.smartbear.com/viewarticle/55046/) you can measure the same when a limited number of users (2-5, depending on the number of TestComplete licenses you have) do the same action concurrently.
If you need to measure the performance of the code to find, for example, the slowest function, than you need to use AQtime, profiler by SmartBear (
http://smartbear.com/products/qa-tools/application-performance-profiling/).
If your tested application is web-based and you need to test the performance of the server and how quickly it responses to the application's requests, then you may consider LoadUIWeb (to check from the end-user point of view,
http://smartbear.com/products/qa-tools/load-testing/) or SoapUI / LoadUI pair (
http://smartbear.com/products/qa-tools/web-service-testing-tool,
http://smartbear.com/products/qa-tools/web-service-load-testing) to do testing on the API level.