[Arm-netbook] Selecting the right Soc for out ARM Notebook project.

Gordan Bobic gordan at bobich.net
Sat May 5 21:30:51 BST 2012


On 05/05/2012 20:32, krasi gichev wrote:
> Agree with you. But think about rest of the system. Having "fast"
> network and SATA means that you need SATA storage - probably HDD - it
> will be insane to believe that somebody can use this netbook with 4 or
> 8GB of NAND. This HDD adds 100 USD to the device.

I am inclined to agree. There are a number of issues if you are using 
on-board NAND:

1) If you are using it raw, it gives you a choice of a total of 1 file 
system worth bothering with. This would be a classic case of 
one-size-fits-nobody.

2) If you are going to use something cheap and simple to work around 1) 
like making it into an MMC, you need a controller to make that happen. A 
cheap MMC flash management controller is going to have terrible 
performance (just look at the performance of MMC cards here:
http://www.altechnative.net/2012/01/25/flash-module-benchmark-collection-sd-cards-cf-cards-usb-sticks/ 
)

3) If you want decent performance you have to do a reasonable flash 
management controller, e.g. a Sandforce one (see the performance figures 
and price tag of the Supertalent RC8 mentioned above), which is going to 
be extremely expensive - SATA would be a cheaper option, especially 
since a decent SSD is cheaper per GB than most SD cards, not to mention 
orders of magnitude faster.

To summarize - on-board NAND might be OK if it is costing next to 
nothing, but in reality, if you have SATA as an option, or even USB, I 
really wouldn't bother.

> 13" displays are not cheap too - if you on the tablet market, you will
> see that even for 10" device (same display as most of the Atom
> netbooks, so cheap one) you have to pay near 200 bucks. Adding bigger
> battery, physical keyboard and so on, and you will hit 300USD final
> price. Removing touchscreen will help to reduce the price, but then
> you loose a lot of functionality of Android.

A laptop with a touchscreen is a waste of time, IMO, as is Android on 
anything but a phone/tablet. It just isn't how we use these devices.

> Nobody will pay this kind of money for single core, ARM device.

Well, there is a company (whose name shan't be mentioned because Luke 
has had a personality clash with them) that is selling 10" A8 laptops 
for $200. And they reckon that the new model that is coming out "soon" 
(not sure what I mean by "soon" here as it was supposed to be out around 
June last year) will be cheaper, not to mention a generation newer.

> As far
> as I know, even dual core Tegra-based Toshiba netbooks are not selling
> very well.

The problem with the AC100 is that it was a sales and marketing 
train-crash. Some bright spark figures that somebody would pay more for 
it (8GB on-board MMC, 512MB of RAM) than for a better Atom netbook. That 
was showstopper number one, but on top of that they decided to ship them 
with Android.

A device with Android without a touchscreen? It should have been obvious 
to everyone that this was going to fly like a lead baloon.

So yes - as far as the out-of-the-box user experience is concerned, they 
sucked and most of them ended up being unsold or returned, hence why 
there are now so many available for a very reasonable price on eBay and 
suchlike.

If they shipped them with a normal Linux distro (Fedora or Ubuntu) and 
priced them up at about 35% less, they would have been a huge success.

Then again, the AC100 has been discontinued for over a year.

For the record, unless I need to do many hours of serious productive 
work (in which case I need more screen res, so I use my 2048x1536 
ThinkPad T60), I use my heavily modified AC100 (cooling modification, 
clocked up to 1.4GHz, internal USB RC8 USB SSD in lieu of the 3G module, 
1280x720 screen) as the primary laptop for just about anything that 
requires me to do work away from my desk. I might replace it with an 
Asus Transformer Prime HD (1920x1200 screen) when that becomes available 
and there is a documented procedure for putting full fat Linux on it 
instead of Android, but considering the price tag is over 5x that of an 
AC100, I don't think I'll be doing it any time soon. Even the 512MB of 
RAM is actually shockingly livable with if you apply a few tweaks to 
make the most of it (see: 
http://www.altechnative.net/2012/01/04/alleviating-memory-pressure-on-toshiba-ac100/ 
).

> This is the price range for x86 devices. Using ARM probably
> will help gaining better battery life, but as far as I know, CPU is
> not the biggest power consumer, it is the screen.

On the AC100 and most ARM laptops, yes, the screen is the biggest power 
drain. Not so on the x86, though. I had a Dell Mini 1012 based on an 
Atom N450 and it sported less than 2 hours battery life and when 
compiling heavily on it for 40 minutes (e.g. kernel building), the 
keyboard was too hot to touch. It is also inadvisable to have it in your 
lap under such load if you think you might ever want to produce children 
in the future.

I figured this was just Dell's engineering being useless, and their 
motherboard designers disabling power management and overvolting the 
CPUs so they can get some QC reject dumpster dived Atom CPUs, but then I 
got a pair of Advancetech N450 uATX motherboards, which had the same 
problem (no working voltage control on the CPUs, twiddling the voltage 
control PHC registers on the CPU does absolutely nothing), so it seems 
this sort of an engineering disgrace is more common than you might 
think. But the punch line is that these motherboards with nothing else 
on them have a peak power drain of 28W. That's just the mobo, DIMM, and 
a Kingston Elite Pro CF card. Not 2.8W - 28W, as drawn from my Class 4 
PoE switch via a DC-DC PoE power adapter.

For comparison, my AC100 is drawing 6W from the AC wall plug, with CPU 
throttling disabled and the screen at full brightness.

Whatever numbers Intel may be putting on their marketing material, I'll 
believe it when I can actually measure it. For now, I am so put off x86 
that I don't think I'll be looking back any time soon.

> At the end, what will be the final target group for this netbook? How
> it is better than tablet or x86 netbook?

Several times better battery life, lower cost (certainly not greater 
cost all other things being equal) and probably also better performance 
- on in most applications, a Cortex A9 will soundly beat an N450 Atom, 
despite a 5x lower power envelope (like for like on a laptop).

Gordan



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