[Arm-netbook] ARM summit at Plumbers 2011

[Gordan Bobic]

On 08/29/2011 05:45 PM, Luke Kenneth Casson Leighton wrote:
> On Sun, Aug 28, 2011 at 11:48 PM, Gordan Bobic<gordan at bobich.net>  wrote:
>
>> The key point isn't the cost, though. The point is that an ARM laptop
>> can be made thinner, lighter and with much, much better battery life
>> than an equivalent x86 one.
>
>   people who've opened up toshiba AC100s have found them to be mostly
> full of air.

Having two of these and having opened one of them up many times, I can 
assure you this is not the case - there is a minimum amount of surface 
area required for the keyboard and touchpad. The front of it is very 
thin, as thin as you can sensibly make the plastic casing without it 
being too fragile. The back is a bit thicker and that's where the SoC 
and mini-PCI WiFi/3G card are - again, there's a limit on how thin you 
can make that. Also there's a full size USB port on the side, and the 
casing is only about 3mm thicker than the USB port, so again, there's a 
limit on how thin you could make it. AC100 is about as thin and portable 
as it would be possible to make such a device.

>> The problem you get into with bigger screens
>> is power consumption - if you use an ARM CPU, the TFT screen is going to
>> be the biggest single power drain which will even out the playing field
>> against x86 at least until large OLED or PixelQi screens become available.
>
>   9in: the OLPC XO 1.75 hardware team budgeted i believe 1 watt or less (!)

I'm not sure that is achievable with a TFT screen, even if it is LED 
backlit.

>   10in: typically 2.5 watts, if you're lucky.  maybe 3.
>
>   11in: 4 to 5.
>
>   it gets hairy after that.  after all, behind the distribution of
> light, it's a square-law.  duh.

For sensible screen power requirements you need tech, like e-ink / PixelQi.

Gordan