How does lowering the processor clock speed increase fps? I've never understood that.
I assume you're lowering the clock speed of the emulated PSP processor, which means the emulated processor runs slower, so your device needs less power to achieve that. This is if your device is not strong enough to emulate the PSP processor at higher clock speeds.
When we talk about Speed (previously known as VPS)
, we're referring to how fast the game is being emulated on your host device via PPSSPP. This is the crucial metric in determining how well your device is coping with the emulation and is generally the most important thing to be concerned with. This is also normally known as FPS for other 3D applications and games. 60 is always the target to aim for.
When we talk about the FPS counter in the context of PPSSPP
, we're referring to how fast the game is rendering internally
. This number is constant and is hardcoded to either 30, 60 or a variable number between them set by the developers. It is not affected by how well your device is coping with the emulation.
So, to put it simply.
Emulated PSP CPU Speed UP
---> Internal FPS UP
(or sustained, especially if originally the PSP itself couldn't cope with the demands and was having slowdowns) ---> Speed (VPS) DOWN
(since demands on the host device is now UP)
Emulated PSP CPU Cpeed DOWN
(to a certain threshold) ---> Internal FPS DOWN
(or sustained) ---> Speed (VPS) UP
(as the demands on the host device goes down)
Use case scenarios for increasing the CPU Speed:-
1. Preventing internal FPS slowdown in graphically intensive situations with certain games that even the original PSP had trouble with.
2. Rectifying remaining GE timing issues
in certain games that errorneously set them to 20 FPS internally.
Use case scenarios for reducing the PSP CPU Speed:-
1. Increasing the speed of emulation to a point. Lowering it too much would cause other severe issues like SPS, jitter and dysfunctional audio.
(In most games, you can actually lower down the PSP CPU clock to ridiculously low numbers like 60-80 MHz and still get sustained internal 30 FPS, which is sufficient if the game was hardcoded to run at 30 FPS in the first place)