Most people here use english and may not understand what your problem is.
"He is using the project files attached to AN58764 with FX2LP. FX2LP enumerated as Virtual com port and drivers are installed on Windows 7 PC. But when he is using this project the CPU consumption is around 10-20%."
Please feel free to correct me, if I am wrong.
But I don't think we have done this measurement with this project. Did you check the CPU load with any other Virtual com port devices?. If you think it is not acceptable for you, please create tech support case so that one of our engineer will test it and help you in providing the solution if there are any.