Underclocking...

[TyBO!]

First off, I'm not complaining about the emus and homebrew that already exist on the GP2X... this is just an idea.

I think it would be a good idea if more coders implanted an option to underclock emus and homebrew games, for the sake of increasing battery life. I've been fascinated with the idea ever since Squidge said he wanted to get SquidgeNgine running fullspeed at only 100 Mhz. At that clockspeed, you could almost double the battery life of your GP2X!

I was thinking the less CPU intensive emulators could do this easily with a little optimization... GB/GBC, NES, Atari 2600, etc. Theretically, you could have many of those early-console emus running fullspeed with sound at 133 Mhz, since, if I'm not mistaken, that's the clockspeed of the GP32, and it could handle those emus running fullspeed.

It'd be cool if these emus/homebrew games could run underclocked by default too.

Make sense? Good idea?

 

[Dzz]

At that clockspeed, you could almost double the battery life of your GP2X!

In general, I think it is a good idea for programs that don't need as much speed as possible to cut the clock rate, but your battery life estimate is certainly not right. There's a lot of things sucking power besides the processor -- the display, audio (when needed), other chips, and so on. Cutting the clock rate probably saves 20% of power consumption at most. Still a good idea when possible.

Somebody should write a little self-contained C function to set the CPU speed (source for such a thing is already available on the archive in the source for the overclocking utility but having a nice cut and paste available might enourage people to use it). However, I bet most devs would use it to overclock instead

 

[DavidBeoulve]

I'll certainly try to make my game-in-planning playable at low clock speeds.

 

[___]

Something which would really save us a lot of battery life would be to make the display light less bright. I assume that cannot be done by software? Cause otherwise somebody would have already coded an appropriate utility. Would using headphones save some power?

 

[reallynotnick]

Would using headphones save some power?

Not much, might extend gameplay by 30secs to a 1 minute. The speakers on the gp2x are not that big.

I do agree though that homebrew games that do not need 200mhz should not run on 200mhz.

 

[TyBO!]

Something which would really save us a lot of battery life would be to make the display light less bright. I assume that cannot be done by software?

IIRC, one of the older firmwares actually had the screens backlight turned down so it was less bright, and according to some users, it had better color contrast.

So I think it can be done by software, it just hasn't been done yet.

Keep in mind, I could be completely wrong. I'm not a coder, so I'm just guessing.