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New 100W USB 3.0 Spec Can Charge Laptops

techweekeurope.co.uk

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Re: New 100W USB 3.0 Spec Can Charge Laptops

#51

Post by [deleted] »

ars wrote: post #50
Dylan16807 wrote: post #49

Earlier quoted context omitted.

I find that argument suspect when I look at all the laptops that run on 19 volts. Internal adapters are a lot messier for 120v. Most computing things love the 12 volt range, my screen uses 19 volts, a fancy light bulb is either LED and low voltage or CFL and gets no benefit from 120. Higher voltage is better for distribution and for very high power loads (including heaters). But a lot of things like low voltage.

> Internal adapters are a lot messier for 120v. Why do you say that? Look at any USB charging plug - very simple inside. You only need "messy" electronics for high power or high (above 80%) efficiency. Basically you would need 20v -> 5v vs 120v -> 5v - there isn't really a lot of difference. (There is some, but not enough to make changing everything worthwhile.) Also, the double conversion isn't great (you would need…

[deleted]

Re: New 100W USB 3.0 Spec Can Charge Laptops

#52

Post by sweis »

X-Istence wrote: post #43
koenigdavidmj wrote: post #38

Earlier quoted context omitted.

And Thunderbolt is already dangerous, given that it's essentially just serialised PCI Express (so you've got a free view into RAM).

There is security against that, you can limit access for thunderbolt devices to various parts of memory, same as you could with Firewire. Thunderbolt is not anymore insecure than Firewire for instance.

There is the ability to protect memory from malicious devices with IOMMU, but it is often disabled by default. My experience with DMA attacks via Firewire or Thunderbolt is that they work out of the box.

Inception is a nice tool to play with if you want to try out DMA attacks: http://www.breaknenter.org/projects/inception/

You may also want to check out the Volatility forensics framework: http://code.google.com/p/volatility/

Re: New 100W USB 3.0 Spec Can Charge Laptops

#53

Post by Dylan16807 »

ars wrote: post #50
Dylan16807 wrote: post #49

Earlier quoted context omitted.

I find that argument suspect when I look at all the laptops that run on 19 volts. Internal adapters are a lot messier for 120v. Most computing things love the 12 volt range, my screen uses 19 volts, a fancy light bulb is either LED and low voltage or CFL and gets no benefit from 120. Higher voltage is better for distribution and for very high power loads (including heaters). But a lot of things like low voltage.

> Internal adapters are a lot messier for 120v. Why do you say that? Look at any USB charging plug - very simple inside. You only need "messy" electronics for high power or high (above 80%) efficiency. Basically you would need 20v -> 5v vs 120v -> 5v - there isn't really a lot of difference. (There is some, but not enough to make changing everything worthwhile.) Also, the double conversion isn't great (you would need…

Having a centralized efficient 20v transformer could actually lead to better efficiency overall. A low voltage DC-DC converter can be far above 80% efficiency without any fancy components.

And when I called 120v adapters messy I meant for the kind of thing I see that runs off 20v. Relatively high-powered computers and game consoles and monitors.

Re: New 100W USB 3.0 Spec Can Charge Laptops

#54

Post by joenathan »

ars wrote: post #48
joenathan wrote: post #21

Earlier quoted context omitted.

That is a picture of a standard USB 3.0 A to B cable. Ex. http://www.amazon.com/Micro-Connectors-Superspeed-Cable-Feet...

No it's not. Look at the plastic "tongue" in the middle of it - it was pierced and they put the power connectors inside it.

Um, yes it is. How about the fact that that particular image is at least 3 years old?

here is an article from nov 2009 http://www.tuexperto.com/2009/11/05/intel-no-desarrollara-el...

and many more http://www.tineye.com/search/d582fc65885700337f2c3ade01878bc...

Re: New 100W USB 3.0 Spec Can Charge Laptops

#55

Post by ars »

joenathan wrote: post #54
ars wrote: post #48

Earlier quoted context omitted.

No it's not. Look at the plastic "tongue" in the middle of it - it was pierced and they put the power connectors inside it.

Um, yes it is. How about the fact that that particular image is at least 3 years old? here is an article from nov 2009 http://www.tuexperto.com/2009/11/05/intel-no-desarrollara-el... and many more http://www.tineye.com/search/d582fc65885700337f2c3ade01878bc...

Seems you're right.

But that makes me wonder where they are adding the pins, there doesn't seem to be room (unless it's inside the connector, with two rows of pins).

Re: New 100W USB 3.0 Spec Can Charge Laptops

#56

Post by ars »

Dylan16807 wrote: post #53
ars wrote: post #50

Earlier quoted context omitted.

> Internal adapters are a lot messier for 120v. Why do you say that? Look at any USB charging plug - very simple inside. You only need "messy" electronics for high power or high (above 80%) efficiency. Basically you would need 20v -> 5v vs 120v -> 5v - there isn't really a lot of difference. (There is some, but not enough to make changing everything worthwhile.) Also, the double conversion isn't great (you would need…

Having a centralized efficient 20v transformer could actually lead to better efficiency overall. A low voltage DC-DC converter can be far above 80% efficiency without any fancy components. And when I called 120v adapters messy I meant for the kind of thing I see that runs off 20v. Relatively high-powered computers and game consoles and monitors.

A centralized transformer wouldn't work well. First you would have to run a lot of very fat wires in order to serve all the outlets.

But worse, power supplies have an optimum efficiency, usually at around the 75% usage point. If you have a power supply large enough to power everything, it's not efficient enough to power just a few things.

> And when I called 120v adapters messy I meant for the kind of thing I see that runs off 20v. Relatively high-powered computers and game consoles and monitors.

And I still don't see what's messy about it. Those things would anyway need a power supply to convert the 20v to whatever they use. You could just as easily put in a 120v power supply (and use thinner wires).

Re: New 100W USB 3.0 Spec Can Charge Laptops

#57

Post by K2h »

It is very interesting to see the group move to a switchable voltage, expecting to support 5V, 12V and 20V. My first reaction was 'oh no.. going to fry some 5V electronics with 20V' but if all the negotiation is done right - and not too easy to spoof it should keep people from building cheap adapters to go inline, request the wrong voltage and fry things.

The voltages are a nice choice.

5V: backwards compatibility. Everything is 5V.

12V: same as your car - lots of things run on 12V. It is easier to build a step down converter than a step up. so that gives the hackers some options.

20V: It was genius of them to step up to 20V. as others have pointed out, charging a laptop (often 17-20VDC required) is perfect. This is also a good choice for keeping the conductor size small in the cable. We get to 100W (wow).

now if you really want to be forward thinking, maybe look at the way electronics have moved from 12V, to 5V, and then to 3.3V. If they want this to be super portable for future use, maybe put in 3.3V - although I can't think of what it would be used for right off.

Re: New 100W USB 3.0 Spec Can Charge Laptops

#58

Post by toomuchtodo »

nicholassmith wrote: post #25
crazygringo wrote: post #23

Earlier quoted context omitted.

Is there any reason you couldn't have both? Use MagSafe at home/work because it's a superior solution, but hopefully Apple hooks up one/all of their USB ports as well to power, so you can recharge with a generic USB cable in a pinch.

It's always possible, but I'm not sure would do it. They like their magsafe, they like the form factor, and they're going down the route of sliming it down. If they could pull it off I imagine they would be but thats probably a while off yet.

Wouldn't they just integrate wireless charging into the battery? To eliminate the need for a port?

Re: New 100W USB 3.0 Spec Can Charge Laptops

#59

Post by K2h »

lallysingh wrote: post #8

20v@5a! Nice! I can't wait to see USB ports instead of the 13.8v ports we currently have in cars. Sadly my 170w laptop still would need a separate adapter.

If you really do need 200W, can't you just plug 2 cables in? I've seen quite a few USB devices that have an extra plug to draw extra juice.

wow... just think if every USB3 port needs an extra 100W of potential from the PSU in your computer (plus the overhead of switching effeciency). So if you have 3 USB3 ports that would mean +300W on your supply (to be safe).

Re: New 100W USB 3.0 Spec Can Charge Laptops

#60

Post by simcop2387 »

jessriedel wrote: post #33
lallysingh wrote: post #8

20v@5a! Nice! I can't wait to see USB ports instead of the 13.8v ports we currently have in cars. Sadly my 170w laptop still would need a separate adapter.

> instead of the 13.8v ports we currently have in cars. That's a bit too much precision for that standard. It's only ~13.8 V when your car is running and the alternator is charging the battery. When the car is off, it'll be 13 V or slightly less.

And even when it's running, you have to expect up to at least 16V, some of the cars and trucks with larger alternators will run a bit higher, I've seen 15V myself but I've always heard that 16V is what to expect.
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