Use OSX
I play a song, and use CCV to control its speed.
When I just play the song, even the speed changed, the quality still sounds fine,
but after i open the gemwin, sounds feels like broken into pieces, i also use the song speed to control the gemwin's frame rates, is that any solution to this problem?
Sorry for the poor english, it's from a helpless Taiwanese....

Maybe your computer just isn't fast enough to handle all the processing.

There are some things you can do.

Run the GEM patch from another computer.

Lower the frame rate of the gemwin. get help for [gemwin]

Increase delay in audio settings.

delete any GUI elements you don't need. (i.e. get rid of sliders and bang buttons e.t.c.) if you need to store numbers, store them with _and [f]

Try increasing block size. get help for [block~]_

Other Things you could try:

Run the GEM patch from another pd instance. I usually run one pd for GEM and other for sound with the -rt option.

Use the [pd~] object.