Actually, the size of the mini DVDs isn't what helped loading, imo. It's the format the disc was designed around.
It's all about CLV vs CAV, the former used for DVD/BR players as well as Sony/MS consoles (excluding XBox I think), while the latter is used for Nintendo consoles and HDDs.
I have not read that CAV makes disc reading faster. It makes data-speed more variable as it will be faster on the outer layers than the inner layers as more of the disc passes under the laser per unit of time, but I have not been able to find anything on how it is faster than CLV. One thing Nintendo
did do to improve average read speed, though, was fill the inner tracks with garbage so that the actual data would exist on the outer tracks where the read speed is at its greatest.
At equivalent speed ratings (1x, 2x, etc.) a CAV drive will have a slower average data speed than a CLV drive, as the speed rating refers to CAV's maximum speed (
source). Unfortunately this source is more looking into read times based on advertized speed ratings of commercial drives which isn't really what we're interested in, which is how these things affect the speed you can
get from a drive. I would not at all be surprised to find out that CLV drives keep constant read speeds by slowing the spin as it goes outside rather than increasing the spin as it goes inside (in other words, the max angular velocity of the drive is the limiting factor, and they're sacrificing the benefits of the outside spinning faster than the inside by slowing it down when reading there).
It's also worth considering how much disc size has to do with the the number of RPMs they can put on a disc. A smaller disc should be able to be reliably spun faster than a bigger disc, so the question is if the smaller disc can spin fast enough to surpass the read speeds on the edges of the bigger disc.[/URL]