No Real-time performance

[MudeLin]

Hello～ On my machine, the real-time performance seems doesn't presented，what could be the reasons?
Details of my computer
OS： Ubuntu 14.04 LTS
CPU: Intel® Core™ i7-6700K CPU @ 4.00GHz × 8
GPU: GeForce GTX 1080/PCIe/SSE2
OpenCV Version: 3.2.0
Cmake Verion: 3.4.1

Experiment settings：
Input image： 480x720,
Average time( time for drawing time is excluded)：
CPU ： 1.39s
GPU ：0.21s

Thanks~