

Timeline of a Car Crash - splat
http://www.drive.com.au/Editorial/ArticleDetail.aspx?ArticleID=56781

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kirse
Link to full original content that was used for this blog-rip:

[http://www.drive.com.au/Editorial/ArticleDetail.aspx?Article...](http://www.drive.com.au/Editorial/ArticleDetail.aspx?ArticleID=56781)

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tjic
From time to time I stop and think about how blindingly FAST computers are.

It's easy enough to click "refresh" on a web server running on your desktop
and wait half a second for a refresh...but then when you ponder that not only
might you be executing a few THOUSAND or TENS OF THOUSANDS of lines of your
own code, but you're executing a few hundred SQL queries, each of which is
doing mind-bendingly complex stuff over in the SQL server ... running the same
CPU ... it just boggles the mind.

I remember when I was amazed at how many computations my overclocked Apple IIe
(running at 2.5 MHz !!!) could do in an eyeblink.

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yan
I had a similar realization when it dawned on me that my computer performed
about twenty instructions before the light from my monitor arrived at my
cornea...

(edit: light travels about a foot in a nanosecond, or 6 inches per clock cycle
in a standard 2ghz pc. multiple simple additions can be done in a single clock
cycle; multiple by number of cores)

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ars
Tthe speed of light is starting to impact how fast cores can be. They need to
take it into account when routing signals on the core. And it's one reason
asynchronous cores work a lot better, since at high hz it's impossible to keep
the entire core synchronized.

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yan
As I understand it, it has been an issue and a major reason for actual cores
being as small as they are. The time a signal takes to propagate from one
section of the core to another is significant.

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anamax
Chip sizes are a function of yield and performance. Core sizes are designed to
optimize performance for a given chip size. (Yes, there's a circular
dependence but yield is a huge factor in chip size.)

That said, it's been at least a process generation since a given clock signal
could be used to synch events on the opposite sides of a core, let alone a
(high performance) chip. This is due to both increasing clock frequency and
the fact that propagation speed has gone down as feature size decreased.

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teuobk
Airbag systems are fascinating. They sit around for years, perhaps decades,
deciding over and over again whether or not a crash is occurring. Then, when a
collision does occur, they have to make a decision -- the right decision --
and take action within a few milliseconds.

A false-negative could exacerbate the injuries of the passengers. A false-
positive could cause a fatal crash. No room for error.

Amazing stuff.

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modoc
Your comment reminded me of the Neal Stephenson short story Jipi and the
Paranoid Chip: <http://www.vanemden.com/books/neals/jipi.html>

Worth a read, and very apropos.

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furyg3
Hilariously appropriate!

I enjoyed that a lot, thanks.

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spoiledtechie
Extremely interesting stuff here. Was impressed with how fast the computer
reacts compared to how long it takes a person to be aware they were just hit.

Amazing.

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csbrooks
Also: A videogame running at 60 fps has to calculate everything associated
with rendering a frame, and get the image on the screen, in 16.6ms.

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CrLf
Interesting, but the occupant is probably already aware of the collision
before the two cars touch.

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icey
A) Not always

B) I think they're just making the point that all this occurs before the brain
can register what's going on to begin with.

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baddox
Why is unlocking the doors so late on the list? I would think that instructing
the doors to begin unlocking could be done relatively early in the process.
Perhaps they meant at that point the doors were completely unlocked.

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mhb
Maybe the doors are stronger when locked.

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helveticaman
I'm just glad to see Ford doing engineering.

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keltecp11
I would love to see it with Illustrations. Excellent Posting, well done.

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showerst
I was thinking of doing one, but the few stock images of car cutaways I could
find (<http://www.khulsey.com/stockimages.html>) are $1500 =(.

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nopassrecover
Ouch - nice images though.

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mynameishere
1000 ms - infinity: Occupant stops being aware of collision.

