Thunderbolt 4 is official, will debut in PCs with Intel Tiger Lake CPUs later this year

nanoguy

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In brief: Thunderbolt 4 is here and adds impressive capabilities in every Type-C port that will support it. The new standard is meant to declutter your desk space and push everyone towards universal cables, but USB4 looks more likely to dominate in the long run.

Today, Intel announced the Thunderbolt 4 specification with a series of improvements over Thunderbolt 3. The new standard will offer the same speed of up to 40 Gbps, but is designed to remove some of the confusion that has governed the Thunderbolt 3 realm for a decade.

As expected, Thunderbolt 4 is USB4-compliant and will debut with Intel's upcoming Tiger Lake mobile CPUs, courtesy of the Maple Ridge 8000 Series controller. The new protocol is also backwards-compatible with all Thunderbolt 3 and USB 3.1 (or higher) devices and accessories.

Intel says Thunderbolt 4 will support up to two 4K monitors or one 8K monitor at 60 Hz, which is a welcome improvement over the previous standard. And while Thunderbolt 3 only required 16 Gbps PCIe connections, Thunderbolt 4 requires 32 Gbps of PCIe bandwidth to do its magic and allow external storage speeds of up to 3,000 MB per second.

Thunderbolt 4 docks will support up to four ports in a smaller form factor, and Intel says host PCs will need to support waking from sleep when a device is connected to the dock. Furthermore, these systems will be required to support charging on at least one port, which should put the final nail in the coffin for barrel-type chargers in new laptops.

When you buy a Thunderbolt 4 cable, there's only one flavor instead of the confusing mess of various USB standards that all use the same USB Type-C interface. There are three standard cable lengths of 0.2 m, 0.8 m, and 2 m that are supposed to be less expensive compared to Thunderbolt 3 equivalents. Come next year, we'll also be able to buy Thunderbolt 4 cables that are 5 to 50 meters in length.

Security has also been improved, as Intel requires manufacturers that want to implement Thunderbolt 4 support in their PCs to also provide support for VT-d-based direct memory access. The move comes after experts in the security community have shown how easy it would be for motivated entities to exploit the protocol and get full access to user data on almost any PC with Thunderbolt 3 ports.

This inevitably leads to the question of whether Intel has just made it harder for AMD to get on the Thunderbolt 4 train. Theoretically, there's nothing stopping AMD from coming up with an equivalent feature to VT-d in its IOMMU implementation. On the other hand, AMD seems more interested in USB4, which is expected to become more widespread.

It will also be interesting to see if Microsoft will eventually add Thunderbolt in its Surface products, being that security was the only deal-breaker. And with Apple moving its Mac lineup to ARM with no word on Thunderbolt support, it looks like Thunderbolt 4 could see a rather limited adoption.

Intel says the first PCs to feature Thunderbolt 4 connectivity will be laptops of the "Project Athena" variety that are powered by 11th generation Tiger Lake CPUs.

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My tech enthusiasm must be running out, or maybe its my cynicism is maxxing out, but at this point I just don't believe any cable provides anything beyond basic connectivity until I've done a deep dive on the internal components of the devices at both ends and how they are connected and configured all the way back to the CPU and the BIOS settings. And even then there's a good chance I won't get what I think I've been promised.

This is entirely on the manufacturers and resellers, who have been playing games with re-using similar sounding names to mean vastly different things. A maze of twisty little passages, indeed.
 
Are you saying you've not used a Thunderbolt Dock so you don't think it works? Mac people have been using them for almost a decade now and they work. These docks are not as good as having those connectors internal to your PC as the Docks seem to need a powercycle every 6 months or so, but otherwise they work. As an example, the most recent one I deployed to a user has 2x 1440p monitors, Ethernet, audio and a few USB-A devices hooked to it. And it needs a powercycle every 6 month or so as mentioned.

And I gamed on an external GPU case (Akitio Node) +1060 6GB for about 6 months and it worked very well. The 1060 was probably as bottlenecked by my 2C4T CPU as the x4 TB connection.
 
No I'm not claiming it's wholesale fraud, and I'm not even talking about TB in particular. When you are buying an integrated system like from Apple, you stand a chance of having everything at both ends configured and capable of doing what you expect.

But on the other end of the spectrum, let's say you are an IT contractor at a new location and looking at a PC with a "USB 3 port", some other random device with a "USB 3 port" you want to connect to, and a USB cable you found in a desk drawer. You are now in a complete crapshoot as to what bandwidth you actually have.
 
No I'm not claiming it's wholesale fraud, and I'm not even talking about TB in particular. When you are buying an integrated system like from Apple, you stand a chance of having everything at both ends configured and capable of doing what you expect.

But on the other end of the spectrum, let's say you are an IT contractor at a new location and looking at a PC with a "USB 3 port", some other random device with a "USB 3 port" you want to connect to, and a USB cable you found in a desk drawer. You are now in a complete crapshoot as to what bandwidth you actually have.

It's not even that good, it's worse. The USB-C shaped cable could transfer any of the following:

USB
USB and DisplayPort
USB, DisplayPort, and TB3

And if the cable markings have come off, you're left guessing. At the very least you'll always get USB on the computer side but good luck if you wanted to use that for video out.

Add to that, your peripheral will *not* dumb down to USB-only if it's wired for DisplayPort or TB3. I know of no peripherals that can do this. Who knows what capabilities and requirements it has if the markings have worn off? And those markings aren't always as readable as you'd like even when new.

The standard(s) technically work(s) well. The implementation sucks.
 
Where's that Boo button when you need one?

Every generation of Thunderbolt was released as something much more superior to the current HDMI. And this is the first one that's inferior to the current HDMI.

HDMI 2.1 offers better bandwidth than this, and can play 8K content at 120Hz. And with USB 4.0 coming soon, I doubt anybody will care to develop for this DOA Thunderbolt 4 standard. This should have been released 2 years ago.
 
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Where's that Boo button when you need one?

Every generation of Thunderbolt was released as something much more superior to the current HDMI. And this is the first one that's inferior to the current HDMI.

HDMI 2.1 offers better bandwidth than this, and can play 8K contents at 120Hz. And with USB 4.0 coming soon, I doubt anybody will care to develop for this DOA Thunderbolt 4 standard. This should have been released 2 years ago.
You'd be running your 8k from your RTX card & using thunderbolt for your removable storage...
 
So... what does this mean: "When you buy a Thunderbolt 4 cable, there's only one flavor instead of the confusing mess of various USB standards that all use the same USB Type-C interface"

So TB 4 isn't going to use the USB-C port anymore?

Sounds like Thunderbolt is going to die now, with Intel imposing a bunch of asinine requirements and Apple moving to ARM with potentially no Thunderbolt chipset. So we're back to shitty old USB, being used for inappropriate applications like external storage and video.
 
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