USB 4.0 "USB4" Specification Published

[tuxd3v]

So.. what's changed between this and usb 3.2 protocol? This shit's really confusing. Asrock X570's have thunderbolt 3/usb 3.2 already. What's the 4 do?

USB 3.2 in a nutshell, gives you 2 new SuperSpeed+ modes( IF data are passed trough USB-C conector.. ).

• 10Gb/s
• 20Gb/s

USB 4.0 in a nutshell, gives you 40 Gb/s( doubles the bandwidth.. ), If trough USB-C connector/cable..
Its also compatible with Thunderbolt 3 and older revisions of USB til USB2.0..

if you already have Thunderbolt3( compatible with usb3.1, I believe ?!),
You already have 40 Gb/s..

[edwaleni]

Basically, it is bundle everything into a single cable to get data from point A to point B and let the endpoints decide what to do with it. Bus it, Switch it, multiplex it, tunnel it, device it, display it. The silicon at each end simply negotiates the capability of the cable and then the switch determines its logical path.

[torsionbar28]

What we see in a cheap way, is sending a pair of PCIe( x1 ), via USB 3.1 cables, but I believe no USB protocol is involved, only the communication Line is used( conector/Cable ), the protocol is PCIe..

It is not uncommon for different technologies to share existing layer 1 cabling and connectors. It makes sense. Why re-invent when an existing cable and connector meets your specs?

• Ethernet, Token Ring, T1, and others use CAT5 cable and RJ45 connector.
• CGA/EGA video, Token Ring, and RS232 serial all used DB9 connector.
• Various RF, Audio, Video, and early Ethernet applications use coax cable and BNC connectors.
• FibreChannel, Ethernet, Infiniband, and Myrinet all use 1.25mm optical cabling with LC connector.

These are just a few examples. But yes I agree that consumers are non technical and easily confused, and some additional differentiator like a keyed connector or color coding would be helpful to avoid confusion and potential equipment damage.

[andreano]

Soon to be renamed Ultraspeed USB 4.2.0 Gen 2.2x4 40Gbps?

… consistent with continuing the retroactive renaming of USB3
* USB 3.1 Gen 2 → USB 4.1 Gen 2
* USB 3.1 Gen 1 → USB 4.1 Gen 1

[tuxd3v]

So it is NOT backwards compatible with USB 1.0/1.1? That's a pretty glaring omission. There are tons of older HID devices, printers, label printers, and other devices that don't need much bandwidth and typically have a long service life. People gonna be pissed when they find this out the hard way.

Well, what you say is true..
But it could be that new machines will have 1 or 2 USB 2.0 ports( so that you could use USB1.1 if you want too ), and some USB4.X,
In this way you have USB covered from USB1.0 til USB4..
USB2.0 is backwards compatible with 1.0..
USB4 is backwards compatible til 2.0..

What this mean,
Is that Computers will forget USB3.x, and ship with USB2.0 and USB4 ports..

[Marc Driftmeyer]

So does this support PCIe or not? I think this was one major feature where it still wasn't clear which direction USB would take. I of course hope it does retain PCIe support from Thunderbolt! Everything else sounds great - especially the flexible bandwidth allocation.

Yes it does and for those in the creative arts that deal with Soundtracks, Music creation, Film Production, Animation, etc etc., you bet your ass we want PCIe access. We want as much bandwidth as possible.

See page 66 of the spec and read from there.

Anyone incapable of securing their work environment is on them. Sorry, but knee capping for the sake of `security' by compromising bandwidth is absurd.

[tuxd3v]

It is not uncommon for different technologies to share existing layer 1 cabling and connectors. It makes sense. Why re-invent when an existing cable and connector meets your specs?

Agree

[tuxd3v]

Protocol on top of protocol...

We already have the following mess:
- Super-Slow USB (1.1 low-speed)
- Slow USB (1.1 full-speed)
- High-Speed USB (2.0)
- SuperSpeed USB (3.0)
- USB 3.1 Gen1 which is basically SuperSpeed
- USB 3.1 Gen2 which is SuperSpeed x2
- USB-C which does USB
- USB-C which does DisplayPort
- USB-C which does Power
- Thunderbolt 3 that looks like USB-C and does PCIe
- USB 3.2 Gen1x1 which is the same old boring SuperSpeed
- USB 3.2 Gen1x2, more like Universal Parallel Bus
- USB 3.2 Gen2x1 which is 3.1 Gen2
- USB 3.2 Gen2x2 which is the only improvement over 3.1
- USB that transmits power
*Cables*
- USB-A which is your typical USB port but the cable is A only in one side unless it's one of those weird cables
- USB-B which is used on large hardware slaves (printers, capture cards, MIDI controllers, etc.)
- miniUSB-A, which nobody uses
- miniUSB-B, which is used on smaller devices
- microUSB-A, which nobody uses
- microUSB-B, which is used on phones and some more recent devices
- USB-B 3.0, which is like a USB-B cable but a little taller
- microUSB-B 3.0. When I first saw it I thought it was a proprietary connector, but no, it isn't. It looks weird.
- Cables that work very well but are expensive
- Cables that fail after a few days of use
- Cables that fail every time the freezer turns on
- Cables that claim doing 20Gbps but actually only do less

And now what?
- USB that looks like USB but actually does PCIe?!?!
- USB 4.0 that does Thunderbolt 3?
- USB 4.0 Gen2x2²x4sin(π)?
- AsuMagic's proposal?

And they have the guts to use a word... I believe is "Standard"..
They created this mess with the Ideology to "fix the mess that was the market of connectors and cables.."

But now we have a gazzilion of Standards,
Which is the same has... no Standards at all..

The Unique thing standard there are the first 3 letters "USB"( they are standard in all that mess.. ).

[TheLexMachine]

So it is NOT backwards compatible with USB 1.0/1.1? That's a pretty glaring omission. There are tons of older HID devices, printers, label printers, and other devices that don't need much bandwidth and typically have a long service life. People gonna be pissed when they find this out the hard way.

USB 4.0 also features USB 2.0 data bus, so backwards compatibility is there, through USB 2.0's compatibility with 1.X. The real issue is driver support, as it won't likely be available in Windows 10 for such ancient devices. None of the 1.X devices you mention are really in use anymore, though you can easily find them in junk piles at thrift stores, so it's not going to be a problem for any business, since they would have long since replaced such devices with USB 2.0 ones.

[LaeMing]

I use USB2-12Mb/s (fallback to 1.5Mb/s) as my desktop peripheral bus.

I use faster versions of USB for... well I don't really have a use for it - everything high speed in my life is either inside the box or at the other end of a CAT-6 cable!