With the Spektrum Pro transmitters you can change the frame speed between 16.5, 11 and 5.5msec, it is an option in the menu. Some transmitters have an option to change between analog and digital servo's. If your transmitter has no likewise option then high chance it has a slow framerate (most cheap models do)

The 20msec frame was a standard for analog servo's, they have a build in reset of about 14msec to listen to the new servo info. Digital servo's can instantly have new servo information after the previous one.

If you have a Futaba 3PV, which just costs about 150 dollar I think then you have the T-FHSS mode which can go up to 3msec but again, serious racers mostly want to use Sanwa for their super speed SSR and SXR mode several servo brands do support and Futaba with their SR and UR and also The Flysky Noble pro with the SR up to 1000Hz do become popular as well.