Will Pandora's Mame Port Match The Mame Project Versions?

[gaterooze]

And on another note Notaz has just turned on the L2 cache and blown away any performance numbers you have recently seen....

Notaz rocks

 

[Tobriand]

As I understand it, the CPU doesn't actually change it's nominal clockspeed - it just doesn't do any work at all unless it needs to to maintain a certain framerate.

So, in theory (and again, I stress this is me paraphrasing others - I may have it wrong), you could have Pandora at 500MHz and only use the battery life of 100MHz, once you activate those power saving features of the chip. Assuming, of course, that 100MHz is sufficient for the program in question to work. Otherwise, it'll use all 500MHz.

In the case of current demos, they do not have this set up, so they're using as much power as 500MHz can provide, rather than only what they need. Turn on the power saving, and you get the performance you need without waste of energy.

 

[daemonaholic]

Does the pandora have the "ondemand" cpufreq scaling? On AMD I think it's called Cool'n'quiet and what it does is changing the cpu frequiency depending on cpu load. ie on my desktop if cpu load is at 100%, the freq is 2400Mhz, but when idle it's at 1000Mhz, with a few other frequencies between. Well, it's a very common thing on laptops since a long time ago, and it's becoming popular on desktop cpus since some time..it's nothing new

Note: I'm not an engineer, so this may be a bit inaccurate, but here goes...

Speedstep and Powernow work based on fixed clock cycles....e.g. a PLL for 800mhz, 1000mhz, 1.2ghz, etc, etc. Generally the CPU will default to the highest (or lowest depending on the CPU) clock speed and will wait for the operating system to tell it to raise it's clockspeed, although I believe some of the newer CPU's (Core 2, newer Turions) can update their clock internally.

Since the ARM core's are generally pretty unlocked (atleast the ARM9s - ARM11s), you can dynamically update your PLL anywhere between the minimum and maximum. To make it "ondemand" you would just need to have a daemon running that detected the cpu load and would clock the CPU up (or down) as needed.

 

[atomicthumbs]

And on another note Notaz has just turned on the L2 cache and blown away any performance numbers you have recently seen....

You've just got to find the tiny little switch :lol:

 

[Prophet]

What I think will be much more cool is seeing how low we can get the CPU speed and high the battery life. SNES @ 500Mhz gets 8.5 hours on the beta battery with full brightness. This is going to lead to some 10+ hour times for straight ports of GP2X stuff. Imagine battery life with 200mhz. Awesome times ahead.

 

[quadomatic]

What I think will be much more cool is seeing how low we can get the CPU speed and high the battery life. SNES @ 500Mhz gets 8.5 hours on the beta battery with full brightness. This is going to lead to some 10+ hour times for straight ports of GP2X stuff. Imagine battery life with 200mhz. Awesome times ahead.

indeed