USB 4 set to roll out next year | Hacker News Reader

USB 4 set to roll out next year

engadget.com

36 pointsChuckMcM15 comments

What's the enabling technology behind this? USB4's 40GBit/s is 8x USB3's original 500MBit/s. USB3 was first launched in 2008. Processors have not gotten 8x faster since 2008, so why haven't these kind of speeds shown up sooner?

Just some theories, but I suspect a lot of the enabling probably came from:

A. The work on USB3 to allow more complex negotiation for power, voltage, etc.

B. More experience with managing radio frequency interference as USB gets used in the real world. For example: https://www.intel.com/content/www/us/en/products/docs/io/uni...

C. 40Gb networking in datacenters. E.g., more chip design teams have confidence building line drivers, receivers, and error recovery circuits to work at these rates.

D. Supply. Never underestimate the power of "Well now that we've paid to build the experienced team, what're we doing for 2.0?"

E. Demand. A critical mass of consumers have type-C connectors now and are using it for things like docking stations.

The C64 could communicate with peripherals with the same speed as it could talk to RAM. "Technically" this would also be possible on x86_64 machines right from the start. The "enabling technology" in this case is that electrical RX/TX components can be manufactured in smaller feature size without breaking the bank. USB is succesfull because it is cheap.

This. There are already complaints about the cost of USB 3.2 hardware, because measurably charging a hunk of metal gets a lot harder at high frequencies. They had to get more precise and then start borrowing tricks from SATA and PCIe.

A 6502 could go up to 3 MHz, but I think the C=64 ran its 6510 near 1 MHz because a clock divider was reserving half the bus cycles for the video chip (no dual-ported VRAM). With dies too small for cache, it didn't make sense to make anything faster than fetching instructions from RAM or ROM. Even the Cray-1 was only able to run at 80 MHz (12.5 ns/cycle) because they paid for four banks of 50 ns RAM. And at those speeds, you could just glue straight wires together into a ribbon cable and call it a day.

I love the optimism in this article "its backward compatible, things will just work." But I also wonder when we will stop "improving" things :-)

You'll never take my audio (phone) jack from my cold dead hands: first used in 1877.

https://en.wikipedia.org/wiki/Phone_connector_(audio)

Some technologies are already perfect.

That's not a fair comparison: you're comparing the specific revision of USB with the earliest revision of the audio jack. The first version of the audio jack, in 1877, is the 1/4" mono jack. The version that you're thinking of is the 3.5mm (just under 1/8") stereo jack. According to that Wikipedia article, the 3.5mm mono jack is from the 1950s, and it doesn't say when the stereo version is from. (Amazingly, the original 1/4" is still used, usually for connecting up instruments rather than for headphones.)

He's not confusing them. They're both phone jacks (see the wiki he posted), the 3.5mm and 1/8 alike. You're confusing the fact the 3.5mm is often in phones (its the multiple usages of the word phone that's confusing here).

I understand they're both phone jacks, and I think my comment makes that clear. But I mean, the context is that USB is having yet another version, so their comment ("some technologies are already perfect") seemed to be that the original 1887 jack is precisely the same revision of the phone jack he doesn't want removed from his mobile phone.

I hadn't actually thought of the two meanings of "phone" in my comment, I understood that "phone jack" refers to telephone switch boards. I just assumed they were talking about removal from mobile phones because that's where those jacks are notoriously being removed.

Wow I had no idea, I'm literally telling everyone I know next time I need to complain about my smart device not allowing me to listen to music while it charges.

awesome!

I can't wait to see how they decide to version the different USB 4 generations.

You mean type-c?

He probably means USB4.1 2x2 type C, or something along those lines.

> USB 4.1 Type C with HDMI Alternate Mode without DisplayPort Alternate Mode with Power Delivery

FTFY

Take a look at the misuse of versioning numbers and the addition of Gen's: https://en.wikipedia.org/wiki/USB_3.0#USB_3.2

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