Speed comparison between the cropped VBO and displaylist

The speed comparison between the VBO and displaylist discussed in the previous two times has not been added with cropping (view frustum culling), rendering in my terrainProgramAfter the cropping function is added, the test shows that:
1. After cropping is added, the frame rate of using VBO is equivalent to that of using displaylist to draw frames.
2. No view frustum culling is performed. The observed terrain range in the window is the area after cropping the rendering pipeline. The speed of displaylist varies greatly. One is that the range observed by the camera is the whole terrain range, and the other is the terrain range after the hardware is automatically cropped, in both cases, the speed of displaylist rendering is very different. In the latter case, the frame rate is much higher than in the former case.

VBO and displaylist have the same terrain block for each frame rendering. Therefore, since VBO does not change the frame rate before and after automatic hardware cropping, displaylist should also remain unchanged. Analyze the cause and have two guesses:
First, displaylist is superior to VBO in Processing Automatic hardware cropping.
Second, the video card I am using is faulty and cannot reflect the superiority of VBO.