
The Race to 10/7nm - rbanffy
https://semiengineering.com/racing-to-107nm/
======
BugsJustFindMe
This post is incredibly frustrating to read.

> _" companies A, B, C, and D are producing w, x, y, and z nm transisters"_

> _" you have to ignore what nm they used, because actually w nm = x/2 nm"_

> _continues to use company-specific nm instead of comparable units_

> _reminds you again that the numbers are not comparable_

> _continues to use company-specific nm instead of comparable units_

> _“We’ve also packed them closer together to improve transistor density,”
> said Kaizad Mistry_

Yes, that is what density means. Very good!

> _" And forming the gate itself is also challenging. “Cycle times are
> increasing for this step, driven by the complexity of the stack,” said
> Mohith Verghese, director of global product marketing at ASM International.
> “The metal gate stack is also getting very complicated."_

Oh, it's getting challenging, complex, AND complicated!

> _There are several layers in the metal stack._

I think you just told me that a stack of something has several layers. Also
that the metal gate stack is metal.

> _And issues, such as... all add to increased cycle time.”_

So cycle times are increasing because issues lead to increased cycle time?

...

gah. I want to finish this, but it's just so hard to read a pile, with several
layers of course, of redundant PR snippets.

...

> _performance become limited, mainly by the contact and back-end-of-line,
> because those become the bottleneck.”_

FFFFFFUUUUU

Christ on a cracker, get an editor. Oh...you ARE the editor. < _cries_ >

~~~
semi-extrinsic
There's lots of fun here!

 _> It will cost $271 million to design a 7nm chip, according to Gartner._

Not a million more, not a million less.

~~~
BugsJustFindMe
> _As the size shrinks, less and less area and volume are available_

Wait, are you sure?

~~~
wand3r
Unclear. Sometimes a smaller size like 7nm is actually 10nm. To summarize 10 >
7 BUT 7 = 10.

~~~
RugnirViking
> Cost, of course, is key because only a select group of foundry customers
> with deep pockets can afford 10nm and 7nm

Really? I wouldn't have known that only people with more money can spend more
money

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deepnotderp
All the node names are effectively useless now. A good rule of thumb is that
TSMC 7nm ~= Intel 10nm and they're shipping at approximately the same time.

~~~
toufka
And last time I checked into it, neither has much to do with 7 or 10
nanometers. The 'feature sizes' of old are not actually on that scale, rather
it's more a measure (read: marketing speak) of resolution than of feature size
at this point? I still can't get good answers. As a biologist used to working
with objects that actually do have features on the order of 0.1nm, and volumes
with less than <5nm per side, I'm trying to figure out just how big these
transistors really are to fit into my existing mental models. At what point do
the transistors actually have to start dealing with (can they deal with)
quantum/thermal/structural effects of being so small.

~~~
dingo_bat
> At what point do the transistors actually have to start dealing with (can
> they deal with) quantum/thermal/structural effects of being so small.

I think that was about a decade ago. These things simply cannot work if they
ignore the quantum effects at their size.

~~~
toufka
I guess the better way to ask is when do those effects dominate rather than
merely effect. At what point do structure and feature type need to actually
change?

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SanPilot
It's exciting to see such an incredible rate of advancement; I can't wait to
see what transistors at 7nm and less will make possible. I can still remember
when these same components were measured in millimeters.

~~~
jandrese
Chips that are just like the ones we have now but 30% cheaper? I don't see how
this is going to open up whole new technologies that weren't possible at
10/15nm.

~~~
amelius
Yes, we need technology that increases CPU clock speed above the current
plateau.

~~~
Ductapemaster
Why do you think we need to increase individual clock speeds past their
current limits?

~~~
baq
due to Amdahl's law, it's always better to have a single faster processor than
multiple slower ones.

...but do we really need faster processors? i don't know, but i'd like to have
one :)

~~~
rbanffy
It's easy to think we need faster processors when the architectures we use,
both software and hardware, are incredibly inefficient.

Any modern processor is _much_ faster than the RAM its programs and data live
on, hence the multiple levels of cache inside them. Multi-cores add the
complexity of keeping the memory consistent. Multiple threads per core put
additional pressure on caches while our OSs assume all processors see a unique
and consistent memory image (which requires keeping caches consistent across
cores). Our most common software doesn't run on GPUs before extensive changes.
Only mobile platforms are exploring asymmetric multiprocessing with a single
ISA now.

I don't think we need faster single-thread performance. What I think we need
is to adapt our software, which is designed to run on ridiculously fast copies
of ancient personal computers, to run on computers that instead of mimicking a
successful product of the 80s resemble more what we _can_ do now. We need
software that exploits the SIMD units (predicate bits that prevent branches
are your friends there), that runs well in multiple cores and OSs that can
deal with memory inconsistency between cores (maybe using write-through
instructions for shared data and write-back for process-local stuff). We need
software that doesn't need complicated instruction reordering or speculative
execution.

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microcolonel
My understanding is that the actual pitch is not getting considerably smaller,
despite the (still fairly large) changes in quoted node size.

Also the cost per wafer for TSMC 20nm is still the same as when TSMC 40nm was
introduced, the latter today is about half as much money, AFAIK. 16nm is about
half way between the introductory price of 20nm.

The transistors are getting slightly smaller, but the cost per transistor
seems to be staying the same or increasing; Moore's law really died like... a
decade ago.

These days you see us coming to terms with it. For years we've been telling
people that computing resources are abundant and they needn't worry about
memory or CPU time because their application will double in speed in a year.
This is probably why most websites are awful these days, and take more time
than ever to do things they did nearly 20 years ago in half the time.

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coldcode
Once you get down to 7nm don't quantum effects become harder to deal with?
Don't know much about chip design but I seem to remember as things get really
small it gets harder to isolate components.

~~~
deepnotderp
Yes, quantum tunneling is a real problem and has been an increasingly
dangerous issue as the nodes shrink. Three interesting proposals to try and
mitigate the issue are:

1\. TFETs, aka Tunneling FETs, harness the leakage current itself to drive the
transistor.

2\. Quantum well FinFETs, use the quantum well to constrain the electron
movement and circumvent the problem.

3\. This is more of a stopgap measure, but the usage of SiGe FinFETs with FD-
SOI.

------
deepnotderp
Also apparently GloFo is developing its own 7nm process (its ancestry was at
IBM before GloFo bought them iirc) but _not_ licensing Samsung like with 14nm.

