News USB4 Spec Published

[Admin]

The USB Implementer's Forum has published the USB4 specification.

USB4 Spec Published : Read more

 

[daglesj]

I kind of lost interest after USB Superspeed came out. Until we can transfer modern softwares need for tens of thousands of microfiles at 500MBps instead of 5KBps, any increment is largely just garnish.

Funny how no one bothers to address this issue. Sure I can shift 4K video files at 1000MBps all day long but real world mixed micro data...crawl!

 

[InvalidError]

If the Type-C spec has to be updated to make it compatible with TB3 and require TB3 cables to work, then we're back to the hellish place of cables not being anywhere near universal.

How many different permutations of Type-C do we have now?

• power only
• USB1.x/2 only
• USB3 (singe set of high-speed pairs)
• USB3.2x2 (two sets of pairs)
• USB4.0 (double 2x2 speed)
• alt-modes

I bet I'm missing a few. Better not get your type-C cables mixed up if you don't want to hamstring your higher-speed devices. I'm quite disappointed with how non-universal and cluttered type-C has turned out. I think we're due for a clean slate dedicated to high-speed data bus. I'm thinking along the line of PnP PCIe over fiber. Displays could still connect to this, just need to make them PCIe data sinks and point the GPU's display engine to the monitor's PCIe address, no need for DP encapsulation.

 

[daglesj]

If the Type-C spec has to be updated to make it compatible with TB3 and require TB3 cables to work, then we're back to the hellish place of cables not being anywhere near universal.

How many different permutations of Type-C do we have now?

• power only
• USB1.x/2 only
• USB3 (singe set of high-speed pairs)
• USB3.2x2 (two sets of pairs)
• USB4.0 (double 2x2 speed)
• alt-modes

I bet I'm missing a few. Better not get your type-C cables mixed up if you don't want to hamstring your higher-speed devices. I'm quite disappointed with how non-universal and cluttered type-C has turned out. I think we're due for a clean slate dedicated to high-speed data bus. I'm thinking along the line of PnP PCIe over fiber. Displays could still connect to this, just need to make them PCIe data sinks and point the GPU's display engine to the monitor's PCIe address, no need for DP encapsulation.

Yeah it's a mess. All I want to do with it is push as much data through it as possible. I don't want to run 4K video, a 2080 GPU, mining cluster or fridge freezer off the damn thing.

 

[regs01]

Looks like they keep smoking a lot with this nomenclature. Or they do it intentionally. Either they hate people, so they trying to do worse for us, or either they intentionally helping manufacturers to trick customers with this numbers, pushing people into buying 10 gbit when they need 20 gbit or 20 gbit when they need 40 gbit.

 

[GetSmart]

Should be preferably 40Gbps (such as in Thunderbolt 3 specifications), otherwise its pretty pointless. And making the USB4 devices Thunderbolt 3 compatible (with dual mode) will also help.

 

[InvalidError]

they intentionally helping manufacturers to trick customers with this numbers, pushing people into buying 10 gbit when they need 20 gbit or 20 gbit when they need 40 gbit.

Downselling? It usually goes the other way around: trick people into buying overpriced next-gen stuff they aren't going to need within the system's useful life. It does not work anywhere near as well the other way around since the slower stuff isn't a distinguishing feature that companies can charge extra for anymore.

 

[regs01]

Menufacturers would save costs on manufacturing. 3.2 is cheaper than 4.0 and 3.1 is cheaper than 3.2, kind of.

 

[joevt1]

If the Type-C spec has to be updated to make it compatible with TB3 and require TB3 cables to work, then we're back to the hellish place of cables not being anywhere near universal.

How many different permutations of Type-C do we have now?

• power only
• USB1.x/2 only
• USB3 (singe set of high-speed pairs)
• USB3.2x2 (two sets of pairs)
• USB4.0 (double 2x2 speed)
• alt-modes

I bet I'm missing a few.

I don't think "USB3 (single set of high-speed pairs)" is an option. A cable requires all four pairs because USB-C is reversible.

Some other options: I believe there are different cables for 5 Gbps and 10 Gbps per lane. And different cables for different power delivery options.

The only alt modes I know that require special cables are Thunderbolt (40Gbps) and VirtualLink. I think USB4 (40Gbps) should be able to work with existing Thunderbolt 40Gbps cables (they both use 20 Gbps per lane). VirtualLink is interesting because it changes the USB2 lines to be capable of transmitting USB3 gen 2.

The cable variations allow the consumer to to choose the least capable (therefore least expensive) cable for their need.