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USB-C is about to go from 100W to 240W, enough to power beefier laptops

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Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#461

Post by magicalhippo »

vladvasiliu wrote: post #414
magicalhippo wrote: post #43

Earlier quoted context omitted.

Should be detectable though, at least in many circumstances. USB-PD has bidirectional communication, so at least in theory both ends could know how the cable is performing by comparing voltage and current measurements at either end. If the cable drops too many Watts, the load can be disconnected.

Is this actually a standard, or would that have to be implemented like some sort of "extension"? And if so, wouldn't that break down the "universal" nature of the beast? As in a Dell laptop won't be able to communicate with an HP power brick (unless said extension becomes at-least de-facto standard)? As I've commented elsewhere, I wonder if, at that point, there still is that much of a point in sticking with USB-C fo…

It's not part of the current standard[1] as far as I can see.

There are some mitigations though, like the cables must identify what they can handle (else the high current modes can't be used), and both ends needs to verify the plug and cable etc.

In theory though I don't see why they couldn't include this in the standard.

[1]: https://usb.org/document-library/usb-power-delivery

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#462

Post by x0 »

unparagoned wrote: post #309
alerighi wrote: post #216

Earlier quoted context omitted.

Not using the proper cable could lead also to fires, for example. We are talking about a significant amount of current. If you don't use a cable rated for that current, the cable or the connector will overheat, and possibly start a fire. And it's not a remote possibility. It happened to me with a fast charging phone power supply and the phone, and the cable was the one provided by the manufacturer! The type-C connect…

When I last worked with USB, there were all sorts of resistors over the pins telling you about its capabilities. I'm pretty sure usb-c has that as well. Your device should check the spec of the cable and inly draw the amount if power its rated for

Is a resistor really enough to determine if a 5W cable gets 240W?

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#463

Post by dTal »

alerighi wrote: post #216
skybrian wrote: post #174

Earlier quoted context omitted.

It actually is sort of nice, because "works" isn't binary. It's nice to be able to charge a laptop with what you have, even if it doesn't charge quite as fast. You can transfer data over a cable at lower speeds even if it doesn't run at top speed. Using the "right" cable is performance optimization. This isn't like the old days when plugging things in the wrong way might damage your machine.

Not using the proper cable could lead also to fires, for example. We are talking about a significant amount of current. If you don't use a cable rated for that current, the cable or the connector will overheat, and possibly start a fire. And it's not a remote possibility. It happened to me with a fast charging phone power supply and the phone, and the cable was the one provided by the manufacturer! The type-C connect…

I have also had my phone's USB-C port spontaneously self-destruct, effectively ruining the phone. As you say, burning smells and melted plastic, and I shudder to think if I hadn't been there to power it off and yank the battery.

And just this past weekend, a close friend of mine had their Galaxy S6 drain completely to 0 in a minute or two, and then claim water damage in the boot screen (which tests resistance across the port). The phone wasn't wet.

Both times, the phone wasn't even plugged in. I am beginning to look very askance at USB-C ports.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#464

Post by dTal »

lovemenot wrote: post #446
iainmerrick wrote: post #385

Earlier quoted context omitted.

I find it a bit disconcerting that we're talking about delivering 240 W over a cable that consumers are unlikely to differentiate from a 15 W cable (i.e. USB-C specification) or even from a 2.5 W cable (e.g a USB cable they would have used fifteen years ago). Yes, exactly! It’s foolhardy. And maybe unnecessary -- haven’t Apple just shown that you can get amazing performance with very low power requirements? And shoul…

What you say about efficiency is right, but it's complicated. There are many domestic devices on 110 / 220v AC using less than 250W. They are native DC, but source AC because they must. These devices are not likely to go away soon. In fact they'll proliferate so long as the developing world is still developing. We can also expect proliferation of domestic battery and solar: both DC sources. A standardised domestic mi…

It's a sensible vision, but USB-C is absolutely the wrong tech for it (which, from experience, means it's the tech that will get adopted). The connectors are fiddly and expensive and fragile and unreliable and require a bunch of silicon logic to work. You can't mess about with power delivery stuff, it needs to be robust and cheap. A domestic DC power plug standard should have a single voltage standard, three pins (+,-,G), and be able to tolerate being stepped on without causing shorts.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#465

Post by dTal »

ChrisMarshallNY wrote: post #308
dangerlibrary wrote: post #243

Earlier quoted context omitted.

> Voltage can't go up arbitrarily, but voltage can safely be increased to ~48V or so in most applications. After 48V, humans start to get shocked / hurt, so that's probably the reasonable limit. Car batteries in ICE cars are nominally 12v. Grab both terminals and tell me it doesn't hurt.

When I was a kid, we had this massive high-voltage transformer that produced about 2,000 volts, at some sick amperage. We used it to make jacob's ladders. That was fun. Until I touched the two bars. I woke up on the other side of the room, smelling burning... me . That wasn't fun...

Good god, you were lucky to live!

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#466

Post by IgorPartola »

endgame wrote: post #425
IgorPartola wrote: post #323

Earlier quoted context omitted.

Better: add a color band to the connector. One line for low power, two for medium, three for high.

By the time the relevant committees have worked over that idea, there will be fifteen bands in colours that you need tetrachromic vision to differentiate between.

Can’t do color as people are color blind. Need to do it by number of bands.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#467

Post by unnouinceput »

Ekaros wrote: post #278
mavhc wrote: post #185

Earlier quoted context omitted.

Who's running their vacuum cleaner all evening? My fridge/freezer uses 25 watts average, but the 90% of things I was thinking about was ignoring the heaters and motors, just the lights, computers, speakers etc. Next question, why 5V, when they're talking about 50V. That brings us down to 1/10th the amps. Also this is only inside your house, not for power distribution. Generate your DC power with solar, store it in yo…

25 watts might be average, but what is the peak and consumption during duty cycle?

Exactly my point, but @mavhc didn't get it. You vacuum for 10 minutes, but during those 10 minutes if your refrigerator motor is engaged suddenly your standard 3mm copper wires are going to become white hot and melt and you get a nice warming house fire because you didn't thought of the peak intensity. This statement assumes the 5Vcc as house power outlets.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#468

Post by sokoloff »

izacus wrote: post #436
sokoloff wrote: post #34

Earlier quoted context omitted.

As long as there’s a penny to be made by shaving component costs, probably not. I have USB micro cables that “work” to charge phones or for data but will give voltage throttling errors if used to power an RPi3 or later. This is presumably from using wires internally of too small gauge. I can’t see things like that stopping.

It's not pennies - 0.5m of TB3 cable is 50$. 2m of TB3 cable is 130$. 2m of USB3.1 cable is 15$. Massive difference, don't you think?

By pennies, I meant if someone can sell a substandard (but "mostly works") cable of any variety and have the parts cost $0.10/meter less, the market will ensure that happens.

Was comparing TB2.995 vs TB3, not TB vs USB.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#469

Post by lovemenot »

dTal wrote: post #464
lovemenot wrote: post #446

Earlier quoted context omitted.

What you say about efficiency is right, but it's complicated. There are many domestic devices on 110 / 220v AC using less than 250W. They are native DC, but source AC because they must. These devices are not likely to go away soon. In fact they'll proliferate so long as the developing world is still developing. We can also expect proliferation of domestic battery and solar: both DC sources. A standardised domestic mi…

It's a sensible vision, but USB-C is absolutely the wrong tech for it (which, from experience, means it's the tech that will get adopted). The connectors are fiddly and expensive and fragile and unreliable and require a bunch of silicon logic to work. You can't mess about with power delivery stuff, it needs to be robust and cheap. A domestic DC power plug standard should have a single voltage standard, three pins (+,…

I don't doubt you are technically right.

USB-C is presumably not the final word in USB connectors. Let's hope for both vision and better implementation.

What's wrong with having multiple set voltages? If it's the necessity of semiconductors, is that really so terrible in this day and age?

On a separate note, I hope they'd have properly managed EMI in this standard. USB has so many makers of varying quality, I can imagine cheap, badly-shielded cables and connectors playing merry hell with noise.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#470

Post by ksec »

smoldesu wrote: post #345
ksec wrote: post #289

Earlier quoted context omitted.

But then again Apple GPU were limited to 10W Max and it was a design decision not technology limitation. There is nothing that stops Apple putting in 16 or 32 Core GPU which would bring its GPU performance on par if not exceed market competitors.

> But then again Apple GPU were limited to 10W Max and it was a design decision not technology limitation. No, it was a technology limitation. The reason I know is because of the M1 Macbook Pro, a device explicitly designed to reap the maximum performance benefits of the M1. It was designed with active cooling and still didn't really manage to score much better than the M1 Macbook Air. Either way, Apple can't just ma…

>a device explicitly designed to reap the maximum performance benefits of the M1.

>Apple can't just magically increase the wattage of their chip and make it run faster.

Because that is not how it works.

The M1 GPU has a maximum TDP of 11W. That is by design. They could push it with higher Clockspeed beyond their optimal level with higher voltage, but that has other testing and reliability implication with cost. It doesn't matter whether you have a large Fan and heat sink sitting on top of or no cooling. You run at 11W Max. That is part of the design. M1 MacBook Air would allow it to run 11W for a fraction of time before heaving TDP headroom to CPU. MacBook Pro allows it to use at its maximum for longer. Since it has a 25W cooling capability.

You want higher GPU performance, throw in more Core. GPU workload are inherently parallel, the only limitation are interconnect and Memory bandwidth. Both of these are are not technical barrier but cost concern.

On a 10W GPU comparison ( And why would you compare GPU that are running at higher watts ) The Apple GPU are doing fairly well in all Metal optimised benchmarks. Compare to AMD Radeon GPU which also has been optimising on Mac platform. ( Although at a larger node )

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