[Arm-netbook] The future of EOMA-68

[Luke Kenneth Casson Leighton]

On Sat, May 2, 2015 at 10:20 AM, David Lanzendörfer
<david.lanzendoerfer at o2s.ch> wrote:
> Hi
>>What is the future of EOMA-68? Any EOMA-68 with a powerful hardware
>>(like Tegra X1 or Intel Bay-Trail)?
> Or the Loongson[1]: It is "free-er".
> An octa core costs 2500RMB and drains around 30W with nearly twice the
> computational power of an intel Sandy Bridge.
> So before you go for power-eaters++ like Intel or Tegra which even seems to
> enjoy the ride about proprietary GPU design, let's just use the dragon core.


 the curreent Loongson is, as you say, 30W.  EOMA68 (Type I) is a
maximum of 5W, where the comfortable operating thermal limit is
actually 3.5W - literally a tenth of the Loongson's power budget (and
that's just the processor).

 also, the Loongson processors are designed around a
Northbridge-Southbridge architecture: ironically the best chip to use
is the AMD CS5536 (the same IC that was used in the OLPC XO-1).

 also, they require a 64-bit RAM interface (minimum) - i believe they
might even require dual 64-bit-wide RAM interfaces.  the power
consumption from the memory alone is therefore going to be something
of the order of 8 to 10 watts at 1333mhz or so.

 so for a full Loongson system you would not be looking at a 30W
budget, you would be looking at more like a 40 to 45W budget.

 by contrast, for example with the A20 PCB we're looking at 32-bit
wide 800mhz DDR3 RAM and that uses only around 350mW (0.35W), and the
A20 itself only uses about 2.5 watts, flat-out.

 the difference then, david, is absolutely enormous, making them
totally unsuitable for EOMA68.

 Loongson processors would however be *perfectly* suited to the
EOMA-200 standard, which is designed *exactly* for this type of
higher-powered processor.

 however, as i am currently focussed on the easier-to-fund EOMA68, as
a way to bootstrap up to profitability by which i can then focus on
the *other* standards later, it would be foolish of me - unless you
can find the funding and provide it to me - to change direction at
this exact minute, especially when things are close to crowd-funding
and take-off.

does that help clarify?

l.