Double Dragon arcade PCB overclock? (reduce slowdown)

[cr4zymanz0r]

So, this is a longshot but I figured I'd ask

Anyone who's played the original Double Dragon arcade board recently probably recalls that the slowdown in the game is pretty abysmal with any decent amount of enemies on screen. I can normally overlook smaller performance issues and slowdown on older games, but it's so bad on this one that I really makes the game a lot less enjoyable.

Some people have also claimed that some of the pirate boards eliminate/reduce slowdown due to having a faster CPU. So, would anyone know how to go about overclocking the original PCB to fix a lot of the slowdown? From what I've read it has 2 CPUs: M6309 @ 3.58MHz, HD63701 @ 2MHz.
I don't know which CPU is used for what, so I don't know if one or both of them would need to be OC'ed to reduce slowdown. Even if I knew I wouldn't really know where to go from there other than assuming I'd need to find out which pin of the CPU is the clock input, find out what clock is being input to it currently, then disconnect the pin and use a crystal oscillator with a higher clock to connect to it to overclock. Even if those assumptions are correct, there's still complexities to figuring that all out.

[parodius]

I’ve been thinking about this as well, since overclocking the main CPU in MAME gave me a much better framerate overall...

On my PCB the main CPU runs pretty hot without overclocking, and If my memory serves me right when I looked into it, it is already running at a higher frequency than the spec.
As DD PCB parts seem to fail quite often, I would definitely think about adding at least a heatsink on the CPU and maybe even some more active cooling with a fan, if we actually performed overclocking on a real CPU.

Caius might have some input on the topic, as he seems to know those boards inside out (he repaired mine, among many others).