Thunderbolt 5 Could Double Bandwidth to 80 Gbps, Intel Leak Suggests

I don’t know where the USB standard is heading.

It's ceased being a "standard" and become an umbrella term for a huge, messy heap ("stack" sounds too coherent and organised) of - sometimes competing - protocols.

Problem is, I think the "Universal" port is an idea who's time has come and gone. USB 2-3, great in its time - cheap to implement, cheap cables and good for everything from a keyboard to a regular external SSD, while video interfaces remained totally separate. Now, they're trying for a single port that can be used for everything from a keyboard/mouse (which still only need USB 1 speeds) through a fast SSD (even so, USB3.0 still covers the majority of applications) through to super-high-speed SSD arrays, and 8/16k displays... which are only used by a tiny fraction of customers (and which will therefore always cost a fortune). Meanwhile, the need for boring old USB2/3 devices isn't going away - because those protocols are more than good enough for things like keyboards, mice, MIDI, backup drives and the typical home/small office network.

The problem with catering for such a wide range of cases via a single universal port is that CPU and GPU resources don't grow on trees - CPUs supply a finite number of PCIe lanes, or equivalent, GPUs support a limited number of DisplayPort streams, so while they may be able to drive half a dozen USB2/3 ports they don't have the resources to drive more than a couple of high-bandwidth universal ports. Sure, manufacturers can add switching arrangements to share resources between ports but that adds expense and complexity (and obscure rules as to what permutations of devices you can plug in to the "universal" ports) so what we get is fewer holes in which to plug stuff.

The height of the stupidity is combining video, charging and data - forcing three independent sets of resources to compete for the same precious universal port... because, otherwise, when you put your laptop on the desk you might have to plug in two or three cables rather than one. Oh the humanity! (I mean, this was more of a point back in the good old days when you were talking about half a dozen honking great D-connectors that had to be screwed in place, but popping in 2-3 modern connectors takes seconds) - and using a display as a dock made sense back in ~2010 and the days of the 1440p Thunderbolt display, which left plenty of spare bandwidth to drive other ports. Nowadays, with 4k commonplace (so, 4x the bandwidth), 6k and 8k bubbling under along with HDR, higher refresh rates etc. it's the displays that are really driving the bandwidth requirement - so trying to share the same channel with other, unrelated data is just dumb.

The size of laptops is already fixed by the keyboard, display and battery - so there should be no shortage of space for ports (use mini-connectors if you really must... that's a separate issue from universal ports). The only demand for "universal" connectors is on mobiles where there really is limited space - but the future of mobile is probably totally wireless (because a mobile with a cable connected isn't... mobile).

...and while we don't want to be the "640K is enough for everybody" guy, the reality is that a huge number of use cases are more than adequately covered by USB3 and 4k displays, and will be for several years. SSD speed and capacity doesn't seem to be doubling every 18 months any more, and the resolution of the Mk1 Eyeball isn't increasing, either.

I was hopeful USB4 would just mandate TB3 across the board after Intel donated TB3 to the USB consortium, but USB4 only mandates TB3 support in USB4 hubs.

The USB consortium made a new 40gbit standard based on TB3 for USB4… which along with their flailing on PowerDelivery has made me lose faith in that group. The USB consortium removed 12V from the standard Power Delivery fixed voltages, allowed companies to add any fixed voltage to their adapters, and have now added a variable voltage to the standard.

I don’t know where the USB standard is heading.

They should abandon the U in USB for starters. How USB is still Universal with all these decisions is a bit of a joke.

So much for USB naming simplification. Why not just name it USB 5?

The naming scheme was fine until 3.0 when they decided to really confuse things with renaming it to USB 3.1 Gen 1, USB 3.1 Gen 2 and USB 3.2 Gen 2x2, unless you know what the speed of those standards are it's meaningless.

If the tech community gets confused the general public must be completely lost. To be honest I'd rather them use speed numbers instead of generic numbers, so at least the USB host is 5Gbps or 10Gbps etc and if the device is one of those that is what you get.

So much simper if the PC says USB 10Gbps and the device you want to use says USB 10Gbps, instantly you know that's the fastest you'll get, or if the device your plugging in only does 5Gbps into a 10Gbps port you know you will only get half the speed.

The naming scheming was fine until 3.0 when they decided to really confuse things with renaming it to USB 3.1 Gen 1, USB 3.1 Gen 2 and USB 3.2 Gen 2x2, unless you know what the speed of those standards are it's meaningless.

If the tech community gets confused the general public must be completely lost. To be honest I'd rather them use speed numbers instead of generic numbers, so at least the USB host is 5Gbit/s or 10Gbit/s etc and the device is one of those that is what you get.

So much simper if the PC says USB 10Gbit/s and the device you want to use says USB 10Gbit/s, instantly you know that's the fastest you'll get, or if the device your plugging in only does 5Gbit/s into a 10Gbit/s port you know you will only get half the speed.

No, they screwed up USB2 as well, and USB3 is a bigger mess than you think.

USB2.0 was announced as being 480mbit, but then the companies lobbied to allow USB1.1 devices(12mbit) to be marketed as USB2.0 so the USB consortium created “USB 2.0 Full Speed” which was identical to USB1.1 and “USB 2.0 Hi-Speed” which was the new 480mbit standard.

USB3 20gbit was launched and is entirely different and electrically incompatible from the USB4 20gbit standard. USB4 20gbit controllers are not mandated to work with USB3 20gbit. USB4 also has a 10gbit mode that is not backwards compatible with USB3.0 for some reason.
Example BS:
[LIST=1]
* It would be valid for a company to make a 10gbit USB4 device that doesn't work with USB3 10gbit.
* It is likely that a USB3 20gbit peripheral will not work at 20gbit on a USB4 port even though USB4 ports are mandated to have a 20gbit mode(40gbit isn't mandatory).

The current TB4 does not have enough bandwidth for the following:

M.2 PCIe 3 x 4 at full speed in an external TB4 enclosure. Never mind M.2 PCIe 4 x 4.
HDMI 2.1 Alt mode. (48Gbps)
DisplayPort 2.0 Alt mode. (80Gbps)

An Apple 6K HDR 10bit display requires a lot of bandwidth. Combining 2x DisplayPort 1.4 together has been done, but HDMI 2.1 or DP 2.0 Alt mode over USB-C is a much better solution.

Once you factor in overhead, a future TB5 @ 80Gbps can't even handle DP 2.0 at full speed.
TB6 anyone? 160Gbps! Will it be enough for M.2 PCIe 5 x 4 that's coming 2nd half of 2022?

The current TB4 does not have enough bandwidth for the following:

M.2 PCIe 3 x 4 at full speed in an external TB4 enclosure. Never mind M.2 PCIe 4 x 4.
HDMI 2.1 Alt mode. (48Gbps)
DisplayPort 2.0 Alt mode. (80Gbps)

An Apple 6K HDR 10bit display requires a lot of bandwidth. Combining 2x DisplayPort 1.4 together has been done, but HDMI 2.1 or DP 2.0 Alt mode over USB-C is a much better solution.

Once you factor in overhead, a future TB5 @ 80Gbps can't even handle DP 2.0 at full speed.
TB6 anyone? 160Gbps! Will it be enough for M.2 PCIe 5 x 4 that's coming 2nd half of 2022?

TB3, USB4, and TB4 support DisplayPort2.0 in one-way mode. They use both 40gbit connections(normally one up, one down) to make a 80gbit one-way connection.