There are some cases when Move between pages is slow, particularly for page 1 -> page 2 -> page 1, the final page 2 -> page 1 is also slow.
The reason for this might be due to a long time to expand a page by dviout. When a high-resolution font is used, the process data becomes large, and it takes time. Even for a gray scale display, a 400 dpi or smaller font would be better. For a particularly slow PC, use a 118 dpi font instead of using gray scale.
Also the move between page is slow when the font cache buffer is too small because of frequent flushing. See "Help -> Buffer info" (Buffer Information). The size of this buffer is defined by -bf:.