[Arm-netbook] uh-oh....

[lkcl luke]

On Thu, Dec 29, 2011 at 8:20 PM, Gordan Bobic <gordan at bobich.net> wrote:

> Does anyone know if a NEON equipped ARM can handle real-time video
> decoding at a sufficient speed?

 it's something like... 720mhz single-core can just about handle....
720p.  i think.  you need 4x that to do 1080p30, and 8x to do 1080p60
(which is the full HD standard).

 the problem is not so much the NEON itself, it's that the amount of
data involved, just in 1920x1080 at 30fps, is 190mbytes per second.  if
you want to do the full HD standard that's double - 380mbytes per
second.

 in other words, it doesn't matter for ARM CPUs that haven't taken
this into account, even if you have 800mhz DDR2 RAM: the data transfer
rates will be bitch-smacking the caches and saturating the internal
buses.

 bottom line, you really do need an ARM CPU that has an internal
architecture which takes into account these massive data transfer
rates.  which is why i really like the allwinner a10, because it's
designed to cope with _four_ times more data than 1080p30.

 l.