Discussion:
Cost of gates, components
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Jeremy Cowles
2008-07-24 21:54:10 UTC
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I am making a little script to analyze the dollar value/cost of the circuits
created in Logisim. Does anybody know of some source I can use to find the
prices for this stuff? Like the actual dollar value of an AND gate, or the
cost of wire?

Jeremy
Jeremy Cowles
2008-07-24 22:24:17 UTC
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If anyone is interested, you can use the script on your circuits like this:

~cs61c-aw/pub/coster.py file.circ

Where file.circ is your circuit file. The dollar figures are totally made up
right now, but hopefully I will find some real component costs online
somewhere.
Post by Jeremy Cowles
I am making a little script to analyze the dollar value/cost of the
circuits created in Logisim. Does anybody know of some source I can use to
find the prices for this stuff? Like the actual dollar value of an AND
gate, or the cost of wire?
Jeremy
Kevin W.
2008-07-25 18:33:18 UTC
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Transistors are crazy cheap on the wafer(chip) level). For example,
take an Intel Atom ($29) for the cheaper version:
http://www.tomshardware.com/reviews/intel-atom-cpu,1947-4.html

The Atom dies all have 47 million transistors - so at this rate: each
transistor is 62 microcents ($6.17 E-7). So giving a conservative
estimate at 50 transistors per gate (provide for routing, power etc),
an enormous logisim circuit with 10,000 gates would cost less than 31
cents ($0.31).

But that's for mass-manufacturing levels, thousands of wafers and
millions of die produced.
The answer you were probably looking for, is discrete devices, which
we CAN build, say on a breadboard or printed circuit board. So you
can look around on DigiKey http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&keywords=
, under MOSFETs, I saw some for about 15 cents, for a single-package
with 2 transistors.

Using our previous size of 10,000 gates at 50 transistors per gate,
our price suddenly jumps to: $37,500. So, that's over 100,000x the
price as before! But this is closer to what we, as students, and not
chip manufacturers, can make. So just update the transistor # per
gate, and the price should be much more reasonable. The $37k is
outrageous, but even just 10,000 transistors (even fewer gates) would
be a beast to assemble on breadboards, or PCBoards, and would likely
span far too much area.

Awesome that you're interested in the manufacturability/costs, and
code in Python.

~Kevin
Post by Jeremy Cowles
~cs61c-aw/pub/coster.py file.circ
Where file.circ is your circuit file. The dollar figures are totally made up
right now, but hopefully I will find some real component costs online
somewhere.
Post by Jeremy Cowles
I am making a little script to analyze the dollar value/cost of the
circuits created in Logisim. Does anybody know of some source I can use to
find the prices for this stuff?  Like the actual dollar value of an AND
gate, or the cost of wire?
Jeremy
[Instr] Albert Chae
2008-07-25 21:27:20 UTC
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This is pretty cool! Although what Julian says is true, it should
still be fun to see how much your CPU in proj3 would cost if you
decided to build it the way Woz and others did in the Homebrew
Computer Club back then.

Albert
Costs for components like gates might vary a bit depending on the specs.
(Plus, it's somewhat rare that anything designed in software such as this would
be implemented using discrete components, but would more likely be synthesized
as a purpose built IC.)
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2556317;keywords=gate
As you can see there are a lot of things to specify. To narrow things down
you'll want to stick to a single mounting type since chips of different types
are rarely mixed on the same board (If your looking to estimate the cost of
something you would put together on a bread board or hand solder on a prototype
board, select through-hole mounting, otherwise pick surface).
You should be able to get a good idea of costs without worrying about the
manufacturer, current, series or supply voltage fields. Just pick the cheapest
unless it's way out of line with the other prices you're seeing or if it's
listed non-stock. If you want your script to be more sophisticated, you could
also have it consolidate gates onto multi-circuit chips.
As for wire, you can search for that as well but, unless you are building a
ponderously huge circuit, I would consider the cost negligible.
Post by Jeremy Cowles
~cs61c-aw/pub/coster.py file.circ
Where file.circ is your circuit file. The dollar figures are totally made up
right now, but hopefully I will find some real component costs online
somewhere.
Post by Jeremy Cowles
I am making a little script to analyze the dollar value/cost of the
circuits created in Logisim. Does anybody know of some source I can use to
find the prices for this stuff? Like the actual dollar value of an AND
gate, or the cost of wire?
Jeremy
Jeremy Cowles
2008-07-27 00:11:44 UTC
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Thanks, that's just what I was looking for. This is just for fun, not real
estimation purposes. I thought it would be something neat to play with. I
was also thinking of adding the ability to submit the cost of your circuit
and compare it against everyone else who has made the same circuit (like for
the ALU or CPU project later).

Jeremy
Costs for components like gates might vary a bit depending on the specs.
(Plus, it's somewhat rare that anything designed in software such as this
would
be implemented using discrete components, but would more likely be
synthesized
as a purpose built IC.)
http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2556317;keywords=gate
As you can see there are a lot of things to specify. To narrow things down
you'll want to stick to a single mounting type since chips of different
types
are rarely mixed on the same board (If your looking to estimate the cost
of
something you would put together on a bread board or hand solder on a
prototype
board, select through-hole mounting, otherwise pick surface).
You should be able to get a good idea of costs without worrying about the
manufacturer, current, series or supply voltage fields. Just pick the
cheapest
unless it's way out of line with the other prices you're seeing or if it's
listed non-stock. If you want your script to be more sophisticated, you
could
also have it consolidate gates onto multi-circuit chips.
As for wire, you can search for that as well but, unless you are building
a
ponderously huge circuit, I would consider the cost negligible.
Post by Jeremy Cowles
~cs61c-aw/pub/coster.py file.circ
Where file.circ is your circuit file. The dollar figures are totally made up
right now, but hopefully I will find some real component costs online
somewhere.
Post by Jeremy Cowles
I am making a little script to analyze the dollar value/cost of the
circuits created in Logisim. Does anybody know of some source I can use to
find the prices for this stuff? Like the actual dollar value of an AND
gate, or the cost of wire?
Jeremy
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