OT: This Swift thing


S

Steven D'Aprano

You're comparing a one-use device to a trillion-use device. I think
that's unfair.

Tell me when you find an atom splitter that works a trillion times.
Then tell me what it's efficiency is, because it's not nearly 0.1%.

Nuclear bombs may only get used once, but nuclear reactors get used
continuously for years or decades, and like I already said, their
efficiency is around 0.1% (mass converted to energy). There are also
various types of atomic batteries, such as radioisotope thermoelectric
generators, which convert the radiation given off by radioactive
substances to electricity. They are typically expected to have an
effective working life of a decade or more.
 
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J

Johannes Bauer

No. Cost is the issue (development, maintenance, operation,
liability...). Want an example? Here is one:

http://tech.slashdot.org/story/14/0...-engineers-involved-in-faulty-ignition-switch

Yeah this is totally believable. One rogue engineer who clearly did it
all by himself. He just wanted to save the company a few dollars out of
pure love for it. Clearly it's his and only his fault with no boundary
conditions that could have influenced his decision in any meaningful
ways. In fact, there's even a GM company memo that states "Hey Ray, just
do what is sensible engineering-wise and don't worry about cost. It's
kewl." But no, Ray just had to go rogue. Just had to do it his way. Man.
Typical Ray thing.

Cheers,
Johannes

--
Zumindest nicht öffentlich!
Ah, der neueste und bis heute genialste Streich unsere großen
Kosmologen: Die Geheim-Vorhersage.
- Karl Kaos über Rüdiger Thomas in dsa <[email protected]a.aioe.org>
 
J

Johannes Bauer

or:

def make_street_address_map(info_list):
return dict((info.get_street_address(), info.get_zip_code())
for info in info_list)

or, what I think is even clearer than your last one:

def make_street_address_map(info_list):
return { info.get_street_address(): info.get_zip_code()
for info in info_list }

Regards,
Johannes

--
Zumindest nicht öffentlich!
Ah, der neueste und bis heute genialste Streich unsere großen
Kosmologen: Die Geheim-Vorhersage.
- Karl Kaos über Rüdiger Thomas in dsa <[email protected]>
 
M

Marko Rauhamaa

Johannes Bauer said:
def make_street_address_map(info_list):
return { info.get_street_address(): info.get_zip_code()
for info in info_list }

Live and learn. Have been an the lookout for dict comprehensions, but
didn't notice they were already included.


Marko
 
A

Anssi Saari

Gregory Ewing said:
Current draw of CMOS circuitry is pretty much zero when
nothing is changing, so if you didn't care how slow it ran,
you probably could run a server off a watch battery today.

That was before 90 nm when leakage current started dominating over
switching current. But has low power or battery life been in anyone's
interest ever? Or rather, is battery life interesting enough that
marketing would notice? Or maybe it's so that what a marketing guy or a
manager needs is maybe one hour for his presentation so anything over
that is extra?

A few years ago jumbo sized but cheapish CULV laptops suddenly had 10
hours plus battery but did anyone notice or care? Today expensive
Haswell ULT laptops get the same while being relatively thin and light
but again, where's the interest? Apple didn't even bother trying to make
improved battery life a selling point for the 2013 Macbook Air. I was
seriously considering one but I prefer matte displays and cellular
connectivity built in.
 
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G

Gregory Ewing

Anssi said:
That was before 90 nm when leakage current started dominating over
switching current.

Well, if you don't care about speed, you probably don't
need to make it that small. There's plenty of time for
signals to propagate, so you can afford to spread the
circuitry out more.

The point is that "optimising for power consumption" on
its own doesn't really make sense, because there's no
optimum point -- you can more or less make the power
consumption as low as you want if you *really* don't
care about speed in the slightest.

In practice, people *do* care about speed, so it
becomes a tradeoff between low power consumption and
something fast enought that people will want to use
it.
A few years ago jumbo sized but cheapish CULV laptops suddenly had 10
hours plus battery but did anyone notice or care?

I think people do care, it's just that going from
something like 6 hours to 10 hours is not a big
enough change to warrant much hype. If it were
100 hours, without losing too much else, I'm
pretty sure it *would* be made a marketing point!
 
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