Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

anandtech.com

Post reply on HN
Print view View original

141–150 of 279 posts

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#141

Post by fwip »

zanny wrote: post #108
bubblethink wrote: post #91

Earlier quoted context omitted.

Intel said that a couple of years ago, and yet you won't find an AMD laptop/desktop that supports thunderbolt.

One, what AMD laptop? Two, I'd be interested to know if AMD bans board manufacturers from including TB or if they just don't do it because their heuristics say users don't care or want it. I'd imagine now with the rise of USB-C it would be the latter. Before that AMD was stuck on a 5 year old desktop platform that probably couldn't run thunderbolt ports even if board makers wanted to include it.

A couple of newer laptops are coming with Ryzen processors. Off the top of my head, the Huawei Matebook D has an AMD option.

Intel has just now opened Thunderbolt up (the topic of this article), despite the announcement coming two years ago.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#142

Post by mjevans »

sneak wrote: post #127
mjevans wrote: post #117

Earlier quoted context omitted.

This absolutely does need to be way more clear. There should be distinct and visibly obvious branding from the standards group. I should be able to tell by looking at a connector: * If it's claiming to be a certified cable/device or not. * The USB standard it conforms to (version) * The speed of data transfer it supports * The maximum wattage it supports * The maximum voltage it supports * (the connector type, but th…

Why is that? You can't do that from looking at a file with an unknown extension. Physical connector technology and signaling protocol are entirely different things. I'd be fine with literally everything using the same physical connector, but knowing that I can't and shouldn't plug my 5VDC battery-charger into a 110VAC outlet. I still have speakers that are connected by stripping a lampcord pair with my teeth, pushing…

Pick any random USB-C cable.

Can you tell by looking at it what speeds it supports? Is it USB-3 or USB-2? How about the power delivery aspect, how much power is it cable of transferring?

You might be able to tell some of those things from modern cables, if they're bragging about a speed factor, but otherwise it isn't clear.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#143

Post by silotis »

chrisseaton wrote: post #48
pkaye wrote: post #18

Earlier quoted context omitted.

I'm no means an expert but up to USB 2.0 there were 4 pins (2 for power and 2 differential signals for bidirectional data) With USB 3.0 they added 4 more signals for separate transmit/receive. Initially they used 8b/10b encoding and then switched to 128b/132b encoding. They also increased the signaling rate with each generation. Also in the USB 2.0 and earlier the higher level protocols were kind of inefficient with…

> With USB 3.0 they added 4 more signals for separate transmit/receive So is it not actually serial any more?

Serial/Parallel have commonly accepted technical meanings in the context of data interfaces which aren't necessarily intuitive.

Parallel refers to taking a raw bit stream and sending N bits at a time down N wires to a receiver who reads N bits at a time and reconstructs the bitstream. This was a common technique in the early days of computing because it is very simple to implement and low clock speeds meant it was often the only practical way of increasing the throughput of an interface.

As clock speeds increased, keeping each of the N signals in sync became increasingly difficult. This eventually lead to parallel interfaces falling out of favor and serial interfaces becoming dominant.

The defining characteristic of a serial interface is that the data signal itself also serves as the clock signal which keeps sender and receiver in sync.

Modern "parallel serial" interfaces like USB 3 consist of multiple serial links which are multiplexed using a framing protocol of some sort. So from a signaling standpoint they are still considered serial interfaces, even though data is in fact being sent in parallel.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#144

Post by elagost »

WhitneyLand wrote: post #124

What's optional? That's the most important thing to know is what's optional in the spec. That could make it great or a major pain. I'm referring to how many features the specification defines as "optional" for manufactures and that the USB organization requires for logos. This is why even USB-C is a nightmare. Consider a USB-C cable or device port. It could be charge only, data only, monitor support. There are even m…

I very much agree with you. I've deliberately avoided USB-C for this very reason. It's not that hard - I don't buy new gear very often, and I'm still using an old 5th-gen iPod every day - but there will be a day when I don't have much of a choice anymore. Bluetooth headphones, external hard drives, game controllers, media players, phones...

The worst part about USB-C is that it can be implemented so wrong it bricks your device! A Google engineer for a while was testing cables and not infrequently they worked poorly, not at all, or outright fried devices. Granted this was years ago, but now with DisplayPort and Thunberbolt 3 over the same connector, the situation has become even more vague.

https://plus.google.com/+BensonLeung/posts/jGP5249NppF

https://www.reddit.com/r/Nexus6P/comments/3robzo/google_spre...

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#145

Post by humblebee »

mortenjorck wrote: post #77
crooked-v wrote: post #24

Earlier quoted context omitted.

TB3 is already the "all of the above" cable, so hopefully USB4 will be as well.

The problem comes in practice: First, OEMs don’t bundle Thunderbolt cables with a device unless the device actually has a Thunderbolt controller onboard. Meanwhile, USB-C cables retail for $8 while Thunderbolt cables retail for $40. So the end result is that no one actually has “all of the above” cables, but rather a collection of cables with different, often invisible constraints. Maybe the move to free licensing wi…

I like how this was solve for USB A/B connectors by color coding the inside. I'm curious why this wasn't brought over with USB-C, it seems like such a simple solution, though maybe there are just too many variations / combinations for it be of practical at all.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#146

Post by Dylan16807 »

StreamBright wrote: post #97
p1esk wrote: post #84

Earlier quoted context omitted.

Is it fast enough for 4K120 or 8k displays?

Do we need 8K displays at all? https://www.youtube.com/watch?v=ehvz3iN8pp4 https://www.youtube.com/watch?v=VxNBiAV4UnM

So the first video is that framerate is better than resolution for gaming. Not relevant to this discussion. The second is mostly about how screens and eyes work, I'm not sure why you linked it at all.

8K is useful for crisp lines and text on a big close monitor.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#147

Post by xenadu02 »

WhitneyLand wrote: post #124

What's optional? That's the most important thing to know is what's optional in the spec. That could make it great or a major pain. I'm referring to how many features the specification defines as "optional" for manufactures and that the USB organization requires for logos. This is why even USB-C is a nightmare. Consider a USB-C cable or device port. It could be charge only, data only, monitor support. There are even m…

Everything is optional.

USB-IF is for manufacturers, most of whom want to do whatever the cheapest quickest thing is. The user experience absolutely comes second to manufacturing cost and marking convenience.

The naming confusion exists because cheap manufacturers don't want to be branded as the "lesser" product or be offering a "lesser" computer. The confusion aids them. They can ship a slightly cheaper computer or device but market it as USB 3.2 Gen whatever, despite it basically being a USB 2 device.

All features will be optional because mandating features means the chip costs $0.02 more, the cable they slap in the box would be more expensive, etc and they don't want to pay it.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#148

Post by phkahler »

nintendo1889 wrote: post #47
phkahler wrote: post #35

Earlier quoted context omitted.

I'm actually really happy with HDMI. It doesn't change much, has good compatibility and doesn't confuse a video cable for anything else. To me its universality makes it better than display port. My next PC will likely have 2 HDMI ports and that will make me very happy. Lots of USB for other stuff but the speed won't be an issue there - no need for USB 4 data rates because... who needs it?

Oddly, DisplayPort had no royalties and the later revisions had chaining support. So HDMI won over the PC world but DisplayPort and DVI didn't win over the TV world, possibly due to not having DRM by default, afaik. On a tangent, I did see a ~2004 DVI projection-screen tv at a thrift shop once but I couldn't figure out how to get it to output audio. Then it hit me, it uses regular old RCA cables!

Chaining is IMHO not very relevant. Connect one monitor to your PC. Then you connect another. You still need a second cable. The question is which device does that second cable plug into? To me its actually more natural for it to plug in the PC than to the first monitor. I can see use cases, but for the average person it doesn't make a lot of sense. OTOH you need a HDMI output per display for up to N displays and that might be a problem for people with 3 monitors. I have opted to just use a single 55" 4K TV instead of multiple monitors, but apparently I'm in the minority. Even with that, I still want a second HDMI output.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#149

Post by kanox »

silotis wrote: post #143
chrisseaton wrote: post #48

Earlier quoted context omitted.

> With USB 3.0 they added 4 more signals for separate transmit/receive So is it not actually serial any more?

Serial/Parallel have commonly accepted technical meanings in the context of data interfaces which aren't necessarily intuitive. Parallel refers to taking a raw bit stream and sending N bits at a time down N wires to a receiver who reads N bits at a time and reconstructs the bitstream. This was a common technique in the early days of computing because it is very simple to implement and low clock speeds meant it was of…

Thanks! I don't know much about hardware design issues and this is a very readable explanation.

Re: USB4 Specification Announced: Adopting Thunderbolt 3 Protocol for 40 Gbps USB

#150

Post by vel0city »

DaiPlusPlus wrote: post #56
reaperducer wrote: post #41

Earlier quoted context omitted.

I've seen them for sale on Amazon and elsewhere. I always thought they'd be neat to throw in a supplemental kit bag for a second display on the go. I think some of the smaller ones were even bus powered.

Those are USB 3.0-based DisplayLink connectors. Any supposed USB 2.0-based display connectors (I’ve never seen any, I’m just speculating) would have been some VNC-like contraption involving an emulated frame buffer on the host.

I've used bus-powered USB 2.0 display adapters in the past, even up to 1920x1080. They're usually a software-based renderer writing to a frame buffer on the USB device. Big updates or lots of USB traffic meant dropped/torn frames, and lots of extra CPU power used to drive it. It worked well for word processing and light web usage, but you wouldn't be watching an HD movie on it.
Post reply on HN