Updated Thunderbolt 3 controllers add DisplayPort 1.4 support

[Glenwing]

https://www.anandtech.com/show/12228/intel-titan-ridge-thunderbolt-3

 

(EDIT: Actually something else I missed which is pretty huge, previously Thunderbolt 3 displays could only accept video from Thunderbolt 3 sources, not from regular USB-C sources operating via DisplayPort Alternate Mode. The new Thunderbolt 3 controllers can accept both TB3 video and DP Alt-Mode video. That should help TB3 gain more traction. The incompatibility with regular USB-C video sources is a big reason why display manufacturers have not been enthusiastic about implementing it on monitors.)

 

Thunderbolt has been using the DisplayPort 1.2 standard since the Thunderbolt 2 days. A standard DP 1.2 connection gives you 17.28 Gbit/s, which is enough for a single 4K monitor at 60 Hz with 10 bpc color. Originally it was intended that TB3 would upgrade to DisplayPort 1.3, which increases bandwidth by 50% (to 25.92 Gbit/s), but the 1.3 spec was delayed so TB3 went ahead without it.

 

TB3 kept ahead by implementing 8 lanes of DisplayPort (a standard DP connection is 4 lanes), which is basically two full DP 1.2 connections running concurrently, except with the integration of a single stream, not like the literal double cable setups that early 5K monitors used.

 

This solution has its limitations though, because the whole 8-lane thing only works with Thunderbolt 3 monitors. DisplayPort Alternate Mode, which is what normal non-thunderbolt USB-C ports use for video, only uses 4 DP lanes. Thunderbolt 3 ports also support DP Alt Mode output so they can be connected to normal USB-C monitors, but they'll be restricted to 4 lanes of DP 1.2.

 

That would mean if someone released a 5K 60 Hz monitor using USB-C with DisplayPort 1.3/1.4 Alt Mode, a current-gen Thunderbolt 3 port can't run it at 5K 60 Hz, even though it has the same shape port and connector and can run 5K 60 Hz Thunderbolt 3 monitors just fine. That ends up creating confusion, which is definitely the last thing USB-C needs more of.

 

Fortunately, none of that has happened yet, which is why it's good that new TB3 controllers with DP 1.3/1.4 support are being introduced now, before any of that starts happening.

 

On the other hand, it's a bit of a problem that it's still called Thunderbolt 3, since now it will be that much more difficult to tell if you have a Thunderbolt 3 port that can run a certain monitor or not. We already have this problem, since the 8-lane configuration is optional, some TB3 ports only have 4 DP lanes, which means they are only equivalent to a normal DP 1.2 connection, and can't run 5K 60 Hz monitors. And this is just within the TB3 ecosystem, not connecting to anything else. This will only add another layer to that since there are so many different implementations with different capabilities, and they're all just called "Thunderbolt 3". Wasn't the whole point of Thunderbolt to create a single connection that does everything, and eliminating the confusion of so many different ports and cables? Instead we have the same situation except now they all look identical... (*sigh* I predicted this...)

 

Anyway, the new Thunderbolt controllers do allow up to 8 lanes of DisplayPort 1.4 which is cool, but the maximum video bandwidth is essentially unchanged, because the total amount of data across a TB3 connection still cannot exceed 40 Gbit/s. An 8-lane DP 1.2 connection was already 34.56 Gbit/s, so 8 lanes of DP 1.4 won't really add much to that. That said, it's still around 50% more than a standard DP 1.4 connection, almost as much as HDMI 2.1 which maxes at 42.66 Gbit/s. But the main benefit is the updates that come with the DP 1.4 standard, giving it more flexibility with increased 4-lane performance, HDR support, and most importantly Display Stream Compression (DSC), which will allow it to do much higher resolutions and refresh rates with the same bandwidth. No mention of FreeSync support, but that isn't too surprising; it's Intel after all.

[Valentyn]

18 minutes ago, Tedny said:

So, is it will be only Intel tech.... or it finally open standard? 

Still has to be licensed to be used as far as I know.

[Trixanity]

8 minutes ago, Valentyn said:

Still has to be licensed to be used as far as I know.

Intel has stated they planned to open it up and make it royalty-free in 2018 but we've yet to see the details and how open and free it'll actually be. Intel obviously wants it to become ubiquitous and an industry standard but to do that they need to get their competitors onboard in some fashion as well as make it cheaper to implement.

[Valentyn]

2 minutes ago, Trixanity said:

Intel has stated they planned to open it up and make it royalty-free in 2018 but we've yet to see the details and how open and free it'll actually be. Intel obviously wants it to become ubiquitous and an industry standard but to do that they need to get their competitors onboard in some fashion as well as make it cheaper to implement.

 We'll see.

 

I'd love thunderbolt everywhere. I use it on a Mac Pro with a Elgato Hub to run everything in another room for my RAID arrays in early 2014. Was fantastic. Improving it like this is even better.

I just hope it's open soon, so we can see it on AMD systems easily as well.

[Dabombinable]

This really should have been called Thunderbolt 4. Or at least 3.1...

[The Benjamins]

32 minutes ago, Dabombinable said:

This really should have been called Thunderbolt 4. Or at least 3.1...

since this is a minor update, it should be 3.1

 

nice to see this update, but I expect DP to move to 1.5 or 2.0 soon, and maybe bring a new connector also. (to allow for more lanes)

[Trixanity]

1 hour ago, Dabombinable said:

This really should have been called Thunderbolt 4. Or at least 3.1...

Not really. The Thunderbolt specifications haven't changed. It's the controllers that have changed. You could argue controller branding should be better though.

[Coaxialgamer]

4 hours ago, Trixanity said:

Not really. The Thunderbolt specifications haven't changed. It's the controllers that have changed. You could argue controller branding should be better though.

Controllers have changed .Intercompatibility isn't guaranteed  , so it should be named 3.1

[AlTech]

7 hours ago, Dabombinable said:

This really should have been called Thunderbolt 4. Or at least 3.1...

Finally we've found a company/brand worse at numbering than USB....

 

USB: 

1.0, 1.1, 2.0, 3.0 (aka 3.1 Gen1 aka 3.2 Gen 1x1), 3.1 (aka 3.1 Gen 2 aka 3.2 Gen 2x1), 3.2 (aka 3.2 Gen 2x2)

 

Thunderbolt:

1, 2, 3, 3 

 

 10/10 Marketing failure. 

[Guest]

It should be called Thunderbolt 3Xp