Thunderbolt 4

Faster is not always better. Or rather - it is very often not the raw numbers but the overall usability of a product (or completeness of a standard) that makes it a winner.

From my own turf: what has made Bluetooth mesh the winning offering is the inclusion of the complete set of application layer models. This is what enabled the rapid adoption of Bluetooth mesh in buildings.

But back to Thunderbolt 4. It is not faster than Thunderbolt 3. But it includes a number of enhancements that will make the products using it much better. The ones I like the most are:

• Longer cables. Version 3 has been limited to 60cm. Above that amplified optical cables must be used, and while they work just fine, they are expensive. $50 for a cable is a lot. Version 4 addresses that, enabling standard cables up to 2m.
  
  
• Mandatory power delivery an remote wake-up. This makes Thunderbolt 4 a very clean and interoperable interface for all sorts of laptop docking station. This will not only be the domain of high end products. Proprietary docks will be gone for good and a single dock will easily last for a couple of generations of laptops.
  
  
• Memory protection. This one is a bit more sophisticated and plugs a huge security hole in older Thunderbolts (the Intel's official, legal-approved language is it "helps protect"). Thunderbolt uses DMA or Direct Memory Access, bypassing the processor, so effectively a Thunderbolt peripheral could dump the RAM including all security keys and passwords). Intel says this is not that easy, as physical access is needed. True. But imagine you want to throw a slide deck on a projector and someone points you to a USB-C (or Thunderbolt) cable connecting to a projector. By plugging that cable you grant the peripheral a physical access to your machine. And yes that "projector" could potentially siphon the contents of your computer's memory. This feature requires Intel's VT-d (Virtualization Technology for Directed I/O) based DMA protection. This requires the latest silicon from Intel as well as OS support (Windows, Mac OS and Linux already support that). I believe teh mandatory DMA protection for Thunderbolt 4 - certified devices will finally enable broader use of Type-C overhead projectors (*if people will return to conference rooms after COVID...).

Probably the last step in the ultimate simplification of electronics power and connectivity will be Apple's decision to drop lightning connectors altogether. Once that happens, Type-C should be the only socket in phones, tablets, computers and power supplies and universal cables will connect it all in a cleanest possible way.