Rockbox General > Rockbox General Discussion
Portal Player Battery runtime vs compiler
LambdaCalculus:
It's been mentioned in the past that lack of understanding of certain PP registers is the issue. We can't shut off certain parts of the PP chipset that aren't used. (Correct me if I'm wrong.)
Where's a PortalPlayer datasheet when you really need it? ;)
saratoga:
--- Quote from: scharkalvin on November 02, 2007, 12:35:01 PM --- I was shocked to see that GCC was pretty bad
--- End quote ---
You must be easily surprised.
scharkalvin:
I'm using GCC for the AVR processor at work and the performance is
quite good. Maybe we could do better with a professional tool set,
but it hasn't been an issue. In the PC (x86) area GCC probably DOES benchmark
quite good. Then again, that's where it's used the most and has seen the most testing.
The issues with the Portal Player cpu make sense to me, it sounds like a special purpose chip designed for use in media players while Gigabeat is using a GP arm cpu with well know other parts. Oh, well so much for low hanging fruit.
Llorean:
Another point is that on one PortalPlayer CPU (the PP5002 at least) we now perform better than the Apple firmware. It's just our knowledge of the PP502x series that's restraining us.
Considering we're beating the Apple firmware on the early generation iPods, I'd suggest wholeheartedly it's not GCC that's the problem. ;)
LambdaCalculus:
--- Quote from: Llorean on November 02, 2007, 02:36:19 PM ---Another point is that on one PortalPlayer CPU (the PP5002 at least) we now perform better than the Apple firmware. It's just our knowledge of the PP502x series that's restraining us.
--- End quote ---
Yes, that's true. I read that now even the 2nd gen iPod surpassed the OF battery life.
If we just had that information for the PP502x series in our hands... datasheets, register values, anything! It seems that the H10 (PP5020) and Sansa e200 (PP5024) are the worst offenders for battery life; solving this issue should help them out immensely.
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