Originally Posted by Me!
Ok, heres my explanation for the battery life of the PSP. Lets say you're playing a game on the PSP, say Final Fantasy. You're in the overworld and you hit a random encounter. The disc spins up, and writes to the system's RAM the data for the fight, music, polygons, character stats etc, then stops spinning to avoid wasting battery. The battle finishes, and as your characters do their little celebration to hide a loading screen, the disc spins up again and writes some more data to RAM about the overworld while erasing the data about the battle because the battle is over. The data from the RAM is projected to the screen, lather rinse repeat. Because the disc stops spinning, you can play a PSP game while walking around. Can't do that with a movie. Lets compare this to watching a movie.
For those of you who pirate games and movies, (surely none of the honest folk here on the Nuklearpower forums) you've probably noticed that movies tend to be a hell of a lot bigger. This is because of media constraints. Movies tend to be about 2 gigs when downloaded, whereas games tend to still be on CD (700 megs) or if they are big enough to be on a DVD, its at most 1.2 gigs. Now, the data from a movie has to be constantly streamed to the screen because theres just so damn much of it. Movie data is ultra inefficient. This makes the RAM on the PSP absolutely useless, because theres just not very much of it (its somewhere around 40 or 50 megs). What happens when you load the movie is that the disc spins up, it sends some data to the processor which converts that into stuff that gets put on the screen. But it doesn't stop. It keeps spinning, because theres more data to send. Constantly. If the PSP were to write the data to the RAM first, it would just end up being a huge bottle neck. The way it works out, more than the processor, more than the monitor, more than processing electric signals from pushing buttons, the motor that spins that little disc takes up more electricity. Part of the reason watching movies/playing games on a laptop is so inefficient is for this reason. Gaming laptops tend to not perform well on battery life is because for laptops, the processor is the power eater second to the optical drive (DVD/CD ROM) and gaming laptops tend to have electricity hogging processors to push more polygons, plus badass video cards which have their own processors and RAM and have to be cooled compeltely separately.
As far as your CD player goes, its the way antishock protection works that causes the difference in battery life. The CD starts spinning up, and like when watching a movie, it never stops. When you have anti-shock disabled, the laser pulls the data off the CD, runs it through the processor which moves the data to your ears. When enabled, the data is read off the CD and written onto some flash memory. Its this writing time that can result in the longer delay between pushing Play and getting music when using your CD and why if you enable or disable anti-shock while the CD is already playing the music stops for a second or two. The data goes from the flash mem to the processor which converts it to music for your ears. Anti-shock works because when the CD should have skipped, the processor is still reading data from the flashmem and the CD has enough time to spin up and read some more data to the flash mem that you won't notice. This is because the CD can be read faster than the flash mem needs to output data. As far as your two hour time difference with anti-shock enabled, I have to wonder what you're doing while listening to music. I've got a 5 year old Aiwa, and the difference is at most 15 minutes. It could be that if you're doing something really active, the disc has to repeatedly spin up after getting jolted, so this could waste some of the battery. Anyway, thats my take on the PSP battery.
|
