Rockbox mail archive
Subject: games/demos cost on play buffer?
From: George Michaelson (ggm_at_apnic.net)
I've been reading the archives about things like the 2mb->8mb hardware mod,
and the benefit of bigger buffer for disk spin cost, battery life.
My reading of this is that 4x memory for buffering had 20% effect on battery
life, because the spinup cost is high in current drain terms, so the effect of
better buffering is marginal across the costs of reading data anyway.
Extrapolating from this, I infer that the in-memory cost of games and demos
has to be marginal as well, ie if one imagined building a version of the code
without them, the increased memory would give <5% extended battery life if the
memory saved was measured as 1Mb (unlikely?). for a 10hr battery life, thats
30min extra play. For me, thats on the cusp of being worth it. But since I
expect the SH3 codesize is dense, and so the saved memory will be smaller, the
net increase in battery life begins to look marginal (this is only theory:
until I make my build env with a gcc-sh3, I can't say what the cost is)
Is this a fair summation? Is there any other marginal benefit of building a
version without games or demos? Please don't get me wrong, I don't 'dislike'
them, I'm trying to work out what the cost:benefit equation might be.
What other things tend to improving battery life? The backlight costs and LCD
update also look to be marginal savings at this time.
Are there other threads than the 2Mb->8Mb upgrade I should be reading?
Page was last modified "Jan 10 2012" The Rockbox Crew