The "Timer hack" feature is very buggy.

[ravope]

1. Timer hack doesn't have any effect until I enable the "Show FPS counter" (any form, so doesn't matter if FPS or Speed or Both, just choose any of them).

2. If both the timer hack and FPS counter are enabled, it makes the PPSSPP unusable, the games unplayable.
Tested with these games:

Vice City Stories:

If Timer hack and FPS counter are enabled, the PPSSPP freezes.

Colin McRae Rally 2005:

If Timer hack and FPS counter are enabled, the game will behave unexpectedly. Completely unplayable.

[[Unknown]]

Then don't use it. The timer hack reports skewed time to the game (although not as a full picture.) A few games, like Wipeout, start frameskipping internally when they see time moving faster than they expect. So it lowers the FPS of games (if it works) to make them more playable. It definitely does not work with all games and can break many. It's a hack after all.

When games frameskip internally, it is much more efficient than PPSSPP's frameskipping, because they can skip other work PPSSPP doesn't know about. But generally this option is a dangerous speedhack.

-[Unknown]