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Comment: Re:Headline trifecta (Score 1) 77

by MattskEE (#47577611) Attached to: Nevada Construction Project Could Be Tesla/Panasonic Gigafactory

Competition is also good for business because it increases the total size of the market, increases availability and reduces costs from 3rd party vendors (batteries, motor drives, charging stations, etc), and reduces costs of specialized labor (eventually) by growing the labor pool of engineers who design electric vehicles.

Having a big part of a small market is not a good way to go. I think Elon's goal (in addition to any altruism on his part) is to grow the entire market and ecosystem for electric vehicles while holding onto a decent (but perhaps smaller) market share.

Comment: Re:Lots of people criticize this for its obviousne (Score 1) 167

Probably because he doesn't live in China.

This is China we're talking about, with 1.3 billion people. I'm sure that people have already strapped filters onto fans, this one guy just happens to be getting some feel-good-DIY publicity because he's marketing his product. Kudos to him because it seems like a good thing that he's doing this, but I would be amazed if this is actually considered novel in China.

Comment: Re:Hmmm... (Score 1) 164

by MattskEE (#47571627) Attached to: Quiet Cooling With a Copper Foam Heatsink

I agree that this doesn't pass the sniff test. A foam has a low ratio of metal to air, it's the cross-sectional area of the copper that allow vertical conduction of the heat from the heat spreader plate. This has little copper area so conduction is limited. It's further worsened by the random nature of the strands so the heat is conducted laterally as well as vertically and so the conductive thermal resistance is increased because the heat needs to travel a longer path.

So while I'm not saying it doesn't work, I suspect that this foam is more of a gimmick than a properly optimized heatsinking solution.

Comment: Re:not likely (Score 1) 200

by MattskEE (#47537159) Attached to: Cable Companies: We're Afraid Netflix Will Demand Payment From ISPs

I get that the meteoric rise in online video streaming by customers puts pressure on ISPs because if affects the oversubsribe ratio that they can use (which is required to turn a profit) while still providing a good user experience.

But what I don't get is why you can possibly blame Netflix. Your customer requested 100GB from Netflix last month. Netflix supplied it based on your customer's request. If you think 100GB (or however much) data in one month is too much then throttle your customer, but do it fairly based on each customer's usage and don't play favorites with which companies you allow your customers access to. 100GB of Netflix traffic should be treated the same as 100GB of porn, or whatever else your customer is getting up to.

My university's residential internet connection started undergoing major strain several years ago, primarily due to online video. So they implemented traffic throttling. I don't remember the precise details, but it was along the lines of a daily 1GB of unthrottled data between 4PM-1AM after which speed was reduced , and no throttling from 1AM-4PM. This was a completely fair and balanced way of providing a pretty good user experience while limiting traffic during peak hours to avoid congesting the network.

Comment: Re:I disagree (Score 1) 390

by MattskEE (#47484441) Attached to: Verizon's Accidental Mea Culpa

How does settlement usually work for unbalanced connections? My thought is that since the Verizon customers request data from Netflix servers, and Level 3 delivers that data to the Verizon network, then if anybody paid settlement it should be Verizon.

But since this is an everybody-wins situation (Netflix pays level 3, Customers pay Verizon, all customers are happy when the pipes run smoothly) then settlement free peering makes sense.

Comment: Re:user error (Score 1) 710

by MattskEE (#47459927) Attached to: People Who Claim To Worry About Climate Change Don't Cut Energy Use

I don't believe we can change global climate.

Not with that attitude you can't!

But seriously, we are the most powerful race on the planet, we use over 30 billion barrels of oil per year (over 1.2 trillion gallons). Nobody knows exactly how much oil there is, but as a rough estimate from a layman it seems likely that we could estimate that in less than a thousand years we'll have probably burnt over a million years worth of natural carbon storage, i.e. it is being released over a thousand times faster than it was stored.

To me that it as least suggestive that we as a species could have an effect on atmospheric CO2 concentration and through that global climate and ocean acidity.

Comment: Re:Why are we saving a law? (Score 1) 183

by MattskEE (#47307147) Attached to: How Vacuum Tubes, New Technology Might Save Moore's Law

Moore's Law has never been a law and nobody treats it as one.

It started off as an observation which happened to basically be correct. Then it became more of a roadmap, with industry using it to set technology targets and allocating R&D resources so that they can continue following Moore's "Law".

Comment: Re:That would be handy for radio astronomy too (Score 1) 183

by MattskEE (#47307057) Attached to: How Vacuum Tubes, New Technology Might Save Moore's Law

Yeah the graphene comparison is spurious, except that it's a wider audience article and graphene has been getting inexplicably large amounts of press recently.
A fair point, but I still don't excuse them for being part of the graphene press problem instead of the solution.

As for the other comparisons: what's the maximum speed of a MOSFET? You can get silicon BJTs into the hundreds of GHz, but I'm not sure about MOSFETS
Maximum published speed I've seen for a Si N-MOSFET is around 450GHz at 32nm, not sure of the best reference but here is a non-peer-reviewed one I quickly dug up: http://www.intel.co.kr/content... obviously as this is silicon the voltages are extremely low so it can't do much in the way of power but people have made circuits in the 100GHz range

And as for advantages over Group III-V transistors: it works with silicon which is less faffy to work with than GaAs for example.
GaAs is still in play because it's the most mature III-V technology and is capable but application space is being taken over by Si, GaN, and InP so it's not IMHO a great point of comparison. The nice thing about vacuum electronics is that it doesn't require a III-V material which may make for easier integration with CMOS, though there are groups working on III-V CMOS integration. And I don't think there's that much advantage to it being on Silicon, most wafer fab tools can handle a variety of wafer types, the processes are not so different, plus GaN-on-silicon is being produced though it still isn't quite as good as GaN-on-SiC for example.

The full article doesn't actually make a bunch of wild-ass claims and is pretty good. They're not making lots of OMG YOAR NEXT COMPUTAR SI TEH VALVES!!11 claims.
The description of the technology is well-written. But I can make any technology look good by simply not comparing it against the best of its competitors, and outright mis-reporting the capabilities of the technologies I do compare it to. Just because they're not as bad as,many "2D" device papers out there doesn't mean they should get a pass for being deliberately misleading.

Comment: Re:That would be handy for radio astronomy too (Score 1) 183

by MattskEE (#47306795) Attached to: How Vacuum Tubes, New Technology Might Save Moore's Law

1 atmosphere of helium needs to be sealed from air, but mechanically is simpler because of the lower pressure difference.

That's not how partial pressures work at all. It only matters about the relative pressure of each individual gas if you don't want it leaking in. If you want to keep out nitrogen and oxygen it makes no difference if the package has 1atm of helium only or a vacuum.

Comment: Re:That would be handy for radio astronomy too (Score 4, Interesting) 183

by MattskEE (#47304395) Attached to: How Vacuum Tubes, New Technology Might Save Moore's Law

I just noticed another disingenuous aspect to their claim - they say that because this operates at "atmospheric" pressure it will be more reliable than vacuum tubes of yore.

But these vacuum FETs are filled with 1 atmosphere of helium, so the partial pressure difference with the outside world for all other gases will still be the same as though it was operating with a full vacuum, and this device would require the same long-term hermetic packaging as a vacuum tube. It relies on helium to extend the mean free path of the electrons, though to be fair as dimensions are scaled down further from the current 100nm to say 20nm perhaps neither helium nor vacuum would be required. Still it seems to be a very misleading claim.

Comment: Re:That would be handy for radio astronomy too (Score 1) 183

by MattskEE (#47304369) Attached to: How Vacuum Tubes, New Technology Might Save Moore's Law

Vacuum micro/nano-electronics are interesting for RF/mm-wave applications as the transport can be ballistic which could theoretically enable ultra-high-frequencies with scaling of the size.

I haven't yet found a paper for the 460GHz claim in the IEEE Spectrum article so I'm not sure exactly which figure of merit they have picked for that claim, but rest assured that their comparisons to other transistor technologies are highly flawed.

InP devices for example already operate up to 1THz power gain cutoff frequencies and have for some years. Simple circuits including amplifiers have been demonstrated in the 600GHz range with both InP HBTs and HEMTs. Even silicon certainly operates in the multi-hundred-GHz range, not the 40GHz which is for some reason cited in the article. Using graphene as a point of comparison is somewhat laughable as graphene has yet to demonstrate any truly practical advantage over group-IV or III-V transistor technologies, and has never been close to beating other leading device technologies on clock speed despite heavy press coverage.

Comment: Re:The world... (Score 1) 236

by MattskEE (#47233409) Attached to: Are the Glory Days of Analog Engineering Over?

Even though shot noise comes about due to the quantized nature of electrons flowing over a barrier it is not treated at the circuit level as a quantized phenomenon, just as a white noise source like thermal noise.

This is unlike "telegraph" or "popcorn" noise which appears at the circuit level as a definitively quantized noise source.

Comment: Re:Lead is mentioned some 16 times (Score 2) 93

by MattskEE (#47133287) Attached to: How LEDs Are Made

The lead frames are not typically made with any lead, it is just a case of easily confused homonyms.

In "lead frames", "lead" refers to the metal pins coming out of the packages, which are connected to the LED die. It not typically made with any lead content (Pb, element 82) due to RoHS restrictions. It could be made of tin-plated copper, or various alloys of tin, copper, and silver. Older ones would likely have been Pb-plated copper.

The trouble with the rat-race is that even if you win, you're still a rat. -- Lily Tomlin

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