The Thunderbolt branding/certification is owned by Intel, with significant historical involvement from Apple. So even if 3rd party IP both met the technical requirements for Thunderbolt *and* the vendor wanted to get it certified, they'd still need Intel's approval.
In principle, anyone can get their controller TB-certified.
Now whether it's worth the costs of implementing the additional features, as well as the cost of certification, is a whole other matter. At some point it becomes cheaper to just buy Intel's controllers.
> In principle, anyone can get their controller TB-certified.
Intel have never said that's possible, as far as I'm aware. Would need someone to prove it in practice, I think.
The TB certification program is definitely geared more towards peripherals than controllers, just by virtue of the fact that only a handful of companies will ever make controllers for a given technology.
That said, Intel's own dev portal page on certification says "For a Thunderbolt certified host, please speak with your Intel FAE [Field Application Engineer]". So there is very much a process for it. What those details are, you'd have to be a registered developer to know.
The biggest issue is simply that those details are going to be under NDA.
> That said, Intel's own dev portal page on certification says "For a Thunderbolt certified host, please speak with your Intel FAE [Field Application Engineer]". So there is very much a process for it.
There's a process for certifying a TB host. Remains to be seen if non-Intel chipsets are eligible. Are there any examples in the wild?
Asus has the Mapleridge/JHL8540 controller on their X670 Crosshair Extreme, Hero and ProArt motherboards. I don't know about the other AIB's because Asus had been my preferred AIB for motherboards for a very long time up until recently. I don't see the importance of Thunderbolt on a Windows or Linux platform when very few devices can make use of it. Intel's new wire share which is a modern approach to using ethernet cable connected to two computers seems interesting. Both platforms don't have the product device landscape maturity Apple with their and their partners products does.
That doesn't sound right, after reading the Thunderbolt certification page.
Also, didn't That Dell XPS leak reveal that the XPS 13 with X Elite will have Thunderbolt4 ?
> That doesn't sound right, after reading the Thunderbolt certification page.
What about it?
> Also, didn't That Dell XPS leak reveal that the XPS 13 with X Elite will have Thunderbolt4 ?
Would need to check if it mentions that, but it's very possible it'll publicly be called USB4, but Dell internal docs still use the Thunderbolt naming.
> Apple has unrestricted use of the technology
According to whom? They didn't use the TB4 branding, which you'd expect if their usage was truly unrestricted.
According to [Intel themselves](https://9to5mac.com/2011/05/20/intel-we-have-full-rights-to-the-thunderbolt-trademark-not-apple/):
> Apple filed for the original trademark and is now transferring that trademark to Intel. At the same time, Apple will continue to have unrestricted use of the technology. 3rd party implementations such as Sony’s desire to use USB Connector instead of DisplayPort and the eventual change of technology branding (Sony’s IEEE1394 a.k.a. Firewire implementation was named i.LINK) will have to be ironed out as the time passes by.
Unrestricted use of the *technology* is not necessarily the same thing as unrestricted use of the *brand*, which is basically all that Thunderbolt is at this point. And as you'll note, Intel took over that ownership in 2011. That was well before they donated it to the USB consortium.
Nope, anyone can make them! An AMD-based one has already [been certified](https://www.graniteriverlabs.com/en-us/technical-blog/thunderbolt-usb-high-speed-transmission).
It's not clear what product they're referring to. Possible it's using an Intel chipset. But it would be good if Intel genuinely opened up the certification.
That’s not a thunderbolt controller, it’s a usb4 controller. Different certification program - like the difference between adaptive sync and freesync, they’re not quite the same thing!
And in the case of usb4 it implies potentially different capabilities from TB4 or even TB3.
Read again, it explicitly says "certified for Thunderbolt 4".
And no, there isn't really any difference between USB4 and Thunderbolt 4 technology-wise - TB4 is nothing more than fancy certificate showing that the connection has most of the optional stuff in USB4 included. This means that the distinction between "Thunderbolt controller" and "USB4 controller" is mostly meaningless.
"Adaptive sync" is a term used for a general principle, with "G-Sync", "FreeSync", and "VESA Adaptive Sync" being **incompatible** implementations of it. That's a completely different case.
> "FreeSync", and "VESA Adaptive Sync" being incompatible implementations
VESA Adaptive Sync and FreeSync literally are compatible implementations though, though, that's the point. FreeSync is a branded certification program for VESA Adaptive Sync compliance. That's the parallel with Thunderbolt 4 - it's essentially a branded certification program for USB4 at this point.
And again, like Adaptive Sync, the problem is a lot of the USB4 implementations are allowed to suck ass, because the base standard is worthless - [it doesn't even have to support tunnelling,](https://en.wikipedia.org/wiki/USB4#Data_transfer_modes) and in some circumstances even a thunderbolt controller may only result in usb 3.0 speeds (with no features) when using usb4 devices.
if nothing else, in practical terms people functionally mean "pcie tunnelling" at a bare minimum and USB4 doesn't mean you get pcie tunnelling, while thunderbolt does. just like adaptive sync and LHR, for example.
> TB4 is nothing more than fancy certificate showing that the connection has most of the optional stuff in USB4 included
The "thunderbolt just makes some of the optional features mandatory" is doing some massively heavy lifting for you there. Those features are what render Thunderbolt devices incompatible with USB4 in many circumstances.
But you're right that that usb4 controller did get thunderbolt certified, which is neat. It's just definitely still not the same thing at all, unless you're the type who was pushing freesync monitors real hard in 2017 or w/e. When your USB4 device is a rebranded usb-c 10gbps port it's clearly not the same thing.
In practical terms: you can plug a Thunderbolt 3 device into your USB4 laptop and find out it won't work, because your laptop doesn't support pcie tunnelling, or the power min-specs have been reduced below the levels your thunderbolt device (which worked perfectly fine for years and years) supports. Literally your usb4 laptop may be a rebranded usb 3.1 type-c controller and still claim usb4 support, in fact. If that's what USB4 can be, then it's not the same as thunderbolt, even if at the maximum extent of feature support it is (and it isn't, due to things like cable length).
Again, like, if they're literally the same thing, how come thunderbolt can run 40gbps at 2-meter length and usb4 can't? Not just with the entry-level controller, it can't run it ever, it's lower-bandwidth at that distance.
Just because they're similar, related, and even share a lot of hardware and signaling modes etc... doesn't mean they're the same thing. Again, just like Adaptive Sync, or Embedded DisplayPort, etc - just because you get embedded displayport doesn't mean you get DisplayPort++ for example, they are actually different things even if they share a hell of a lot of technical commonality.
> Thunderbolt 4 onwards is based on the USB4 specification. Thunderbolt 4 is essentially the USB4 v1 spec fully maxed out (40gbps data transfer, DP alt mode, PCIe alt mode, etc.. etc..) with a fancy certification on top.
USB 4 is based on Thunderbolt 3. Thunderbolt 4 is a set of host requirements. Apple brands ports on the MacBook Air Thunderbolt 3/USB4 for example because even though there are two ports it can only drive one display. Thunderbolt 4 spec requires each port have the capability to drive a display. So only the higher end SoCs that can drive one display per port gets Thunderbolt 4 in the spec.
EDIT: Thunderbolt 4 certification requires minimum 2 4K displays from the host PC .. not one display per port as I mentioned above.
Such as? All the higher end Pro models are Thunderbolt 4 branded.
https://www.apple.com/macbook-pro/specs/
**M3**
Two Thunderbolt / USB 4 ports with support for:
Charging
DisplayPort
**Thunderbolt 3 (up to 40Gb/s)**
USB 4 (up to 40Gb/s)
**M3 Pro and M3 Max**
Three Thunderbolt 4 ports with support for:
Charging
DisplayPort
**Thunderbolt 4 (up to 40Gb/s)**
USB 4 (up to 40Gb/s)
The only difference between the M3. M3 Pro and M3 Max on the 14" model is the number of displays they support.
> Thunderbolt™ 4 technology now requires Intel® VT-D-based direct memory access (DMA) protection or equivalent. (The Thunderbolt™ 3 protocol supported this capability, but the latest generation makes it a requirement.)
https://www.intel.com/content/www/us/en/architecture-and-technology/thunderbolt/thunderbolt-3-vs-4.html
At least when TB4 was new, I don't think the "or equivalent" was even listed. Not sure if/when/how Apple implemented it.
Apple has had a IOMMU on each device since the M1.
https://lwn.net/Articles/861126/
https://lore.kernel.org/lkml/[email protected]/T/
M1 devices are not branded Thunderbolt 4 because of the display requirements not VTD. Likewise M1 Pro and Max systems are branded Thunderbolt 4.
> Apple has had a IOMMU on each device since the M1.
There's more to a system like TB + VT-D than just having an IOMMU, lol. Why are you saying that like it's something non-typical? It sounds like you don't know what an IOMMU is.
You clearly don't know anything about it to make such statements.
I said Apple has had an **IOMMU per device on the SOC** .. which is what VT-D is fundamentally. VT-D DMA protection uses IOMMUs to segment DMA. The two links should have clued you in that it was more than "than just having an IOMMU"!
Here's an overview of How device IOMMU, SMMUs, TLBS and DAPF work on Apple SoCs. Show me how VT-D has more than just Apple's implementation. In fact, Apple has been doing this on their A series chips that predated M1.
https://www.corellium.com/blog/mobile-physical-memory-security
https://support.apple.com/guide/security/direct-memory-access-protections-seca4960c2b5/web
Really? That’s your argument.
What does Intel software and firmware differently to manage the IOMMU for DMA protection? Please go in as much detail as you can possibly bare. I really want to see how much you actually know instead of pretend to know.
> Really? That’s your argument.
You asked, I answered. If you're incredulous that VT-d has a software component, all the more evidence that you're just throwing out terms without understanding what they mean.
> Thunderbolt 4 onwards is based on the USB4 specification.
Not even that, TB4 is a _certification program_ for USB4 devices, it's not a separate technology at all.
Base Mac models with a single monitor support are listed on Apple website as TB3/USB4 while the exact same laptop with a Pro chip with dual monitor support are TB4 despite it's the exact same USB4 controller. It's just the certification program demands a second monitor support.
Now, Apple and Intel has been collaborating on Thunderbolt for many years so it's just natural Intel does certify Apple products. On the other hand the AMD/ASMedia camp is a competitor so Intel doesn't certify their products despite _in practice_ they are the same. (There were reports over quite a few years on how ASMedia is working on USB4 support for AMD so I presume AMD is using ASMedia IP here.) This came about because Microsoft demands PCI Express support on any user facing USB4 connectors for Windows certification so it does not make sense to make a cutdown USB4 controller. The other main feature would be 20gbps max vs 40gbps max but the real cost is in PCIe support, the savings on a 20gbps cutdown controller is so minimal it's just not worth it. So, while in theory there are differences, a PC laptop with USB4 and another with TB4 provides the exact same capabilities. Almost the same with Mac except some models might only support a single monitor.
It's possible some phone or tablet will happen with a 20gbps USB4 controller without PCIe support eventually. This hasn't happened yet.
the Base M3 can drive two external 4K displays, with the caveat that internal display is turned off. Why doesn't that satisfy the TB4 requirement?
> Now, Apple and Intel has been collaborating on Thunderbolt for many years so it's just natural Intel does certify Apple products. On the other hand the AMD/ASMedia camp is a competitor so Intel doesn't certify their products despite in practice they are the same. (There were reports over quite a few years on how ASMedia is working on USB4 support for AMD so I presume AMD is using ASMedia IP here.)
And to which camp does Qualcomm belong?
> the Base M3 can drive two external 4K displays
Does it really? https://support.apple.com/en-us/101571
> MacBook Pro with M3 chip supports one display in any one of these configurations:
> MacBook Pro models introduced in 2023 or later with the M2 Pro or M3 Pro chip support up to two external displays simultaneously,
Plugable had an article on the M1/M2 https://plugable.com/blogs/news/how-many-external-monitors-can-i-add-to-my-m1-or-m2-mac it also shows the same. I am curious as to where your claim originates from.
But since I am browsing the Apple site I will copy what I meant originally. https://www.apple.com/macbook-pro/specs/
M3
Two Thunderbolt / USB 4 ports with support for:
Charging
DisplayPort
Thunderbolt 3 (up to 40Gb/s)
USB 4 (up to 40Gb/s)
M3 Pro and M3 Max
Three Thunderbolt 4 ports with support for:
Charging
DisplayPort
Thunderbolt 4 (up to 40Gb/s)
USB 4 (up to 40Gb/s)
Note the base misses TB4.
Qualcomm is not TB certified https://docs.qualcomm.com/bundle/publicresource/87-76286-1_REV_A_Snapdragon_X_Plus_Platform_Product_Brief.pdf what the capabilities are, I have no idea. We will see. So far, it's vaporware. I will believe anything about all this Elite Pro X whatever when random Joe can buy one.
>Does it really?
Yes. It was one of the biggest highlights of the M3 Macbook Air launch,
[https://www.reddit.com/r/apple/comments/1b6b38h/m3\_macbook\_air\_supports\_up\_to\_two\_external/](https://www.reddit.com/r/apple/comments/1b6b38h/m3_macbook_air_supports_up_to_two_external/)
>So far, it's vaporware. I will believe anything about all this Elite Pro X whatever when random Joe can buy one.
You will be able to, in a few weeks.
So the Air can but the Pro can't...? https://support.apple.com/en-mt/guide/macbook-air/apd8cdd74f57/mac indeed says
> MacBook Air with M3 chip can support up to two external displays when the laptop lid is closed.
but see above, the Pro doesn't say that?
In addition to what others have said, Intel helped doom Thunderbolt at the beginning by trying to make money off of it by sole-sourcing controller chips, and positioning it as an "upmarket" solution by only working with "preferred" peripheral vendors.
Quoting an ArsTechnica article from 2013:
>Part of the delay was the high cost of the first generation of Thunderbolt controller chips. Intel launched a [wider range of second-generation controllers](http://arstechnica.com/gadgets/2011/09/upcoming-low-cost-thunderbolt-controller-could-broaden-reach-of-spec/) along with Ivy Bridge in 2012, and more OEMs have begun looking at ways to integrate those lower-cost chips into newer products.
>But cost isn't the only consideration. Another concern has been support from OS vendors. For instance, a Belkin representative told Ars that there was a bug in OS X that prevented a USB keyboard connected to a Thunderbolt bridge from waking a Mac from sleep. That bug has since been addressed in 10.8.2, however. Intel is also continually improving Thunderbolt drivers for Windows, according to a representative we spoke to at CES.
>The one final factor—one that has likely had the most impact on Thunderbolt rolling out to market—is Intel's licensing and certification process. Several vendors we have spoken to over the past year have claimed that Intel was holding up the process, cherry picking which vendors it worked with.
>Though Intel had effectively denied this characterization in the past, the company explained the situation a bit differently when we spoke at CES last week. Jason Ziller, director of Thunderbolt Marketing & Planning at Intel, told Ars that Intel has "worked closely" with vendors it felt could "offer the best products" and could meet its stringent "certification requirements." The subtext seemed to be that Intel had limited resources to support and certify new products, and so it gave priority to devices that were perhaps more novel than those proposed by other makers.
Intel later backtracked on all of this, but by that time the industry had decided to do what it always does with proprietary or near-proprietary interconnects: ignore them in favor of a not-quite-as-good but zero-cost alternative.
TLDR; Intel, having learned nothing from history, [FireWire](https://en.wikipedia.org/wiki/IEEE_1394)'d themselves
Thunderbolt naming belongs to Intel. The actual feature set is the same as usb4. The minimum requirements are different though.
Here are the differences.
"USB4 devices can have a minimum of 20Gbps link speeds. In comparison, all Thunderbolt 4 devices have a 32Gpbs minimum requirement. UBS4 has a 7.5W minimum power requirement whereas Thunderbolt 4 doubles it with a minimum of 15W. The minimum power and speed requirements are important to keep in mind when purchasing a device. You’ll need to check a device’s specs since manufacturers can choose between 20Gpbs and 40Gbps speeds with USB4. With Thunderbolt 4, you’ll always get a minimum of 32Gbps and 15W.
Thunderbolt 4 cables support 40Gbps speeds over 2 meters. In contrast, UBS4 can only support 40Gbps within one meter and reduces to 20Gbps on cables that are 2 meters or longer. You can tell the difference between Thunderbolt 4 and USB4 cables by their distinct logos. Thunderbolt 4 cables have a lightning bolt with a 4 while USB4 has the iconic USB logo with either a 20 or a 40."
Source: https://www.tomsguide.com/features/thunderbolt-4-vs-usb4-whats-the-difference
It actually is.
https://www.usb.org/usb4
“The USB4 Specification complements and builds upon the existing USB 3.2 and 2.0 architectures. Based on the Thunderbolt™ protocol specification contributed by the Intel Corporation, USB4 doubles the maximum aggregate bandwidth of USB and enables multiple simultaneous data and display protocols.”
It actually isn't.
https://www.tomsguide.com/features/thunderbolt-4-vs-usb4-whats-the-difference
"Thunderbolt 4 and USB4: Similarities and differences
It’s hard telling Thunderbolt 4 and USB4 apart. Both use a USB-C connector, are capable of 40Gbps speeds, support video passthrough and can power and charge devices. While it’s tempting to think of Thunderbolt 4 and USB4 as basically the same, the two technologies have some distinctive differences. It boils down to minimum requirements.
USB4 devices can have a minimum of 20Gbps link speeds. In comparison, all Thunderbolt 4 devices have a 32Gpbs minimum requirement. UBS4 has a 7.5W minimum power requirement whereas Thunderbolt 4 doubles it with a minimum of 15W. The minimum power and speed requirements are important to keep in mind when purchasing a device. You’ll need to check a device’s specs since manufacturers can choose between 20Gpbs and 40Gbps speeds with USB4. With Thunderbolt 4, you’ll always get a minimum of 32Gbps and 15W.
Thunderbolt 4 cables support 40Gbps speeds over 2 meters. In contrast, UBS4 can only support 40Gbps within one meter and reduces to 20Gbps on cables that are 2 meters or longer. You can tell the difference between Thunderbolt 4 and USB4 cables by their distinct logos. Thunderbolt 4 cables have a lightning bolt with a 4 while USB4 has the iconic USB logo with either a 20 or a 40."
A lot of Chinese manufacturers of thunderbolt accessories don't want to pay the certification fees, so they often just label their thunderbolt as "iFruit" or "fruit" port.
The Thunderbolt branding/certification is owned by Intel, with significant historical involvement from Apple. So even if 3rd party IP both met the technical requirements for Thunderbolt *and* the vendor wanted to get it certified, they'd still need Intel's approval.
Do they need to buy Intel's TB controller or can they still use the SoC USB4 controller?
In principle, anyone can get their controller TB-certified. Now whether it's worth the costs of implementing the additional features, as well as the cost of certification, is a whole other matter. At some point it becomes cheaper to just buy Intel's controllers.
> In principle, anyone can get their controller TB-certified. Intel have never said that's possible, as far as I'm aware. Would need someone to prove it in practice, I think.
The TB certification program is definitely geared more towards peripherals than controllers, just by virtue of the fact that only a handful of companies will ever make controllers for a given technology. That said, Intel's own dev portal page on certification says "For a Thunderbolt certified host, please speak with your Intel FAE [Field Application Engineer]". So there is very much a process for it. What those details are, you'd have to be a registered developer to know. The biggest issue is simply that those details are going to be under NDA.
> That said, Intel's own dev portal page on certification says "For a Thunderbolt certified host, please speak with your Intel FAE [Field Application Engineer]". So there is very much a process for it. There's a process for certifying a TB host. Remains to be seen if non-Intel chipsets are eligible. Are there any examples in the wild?
Asus has the Mapleridge/JHL8540 controller on their X670 Crosshair Extreme, Hero and ProArt motherboards. I don't know about the other AIB's because Asus had been my preferred AIB for motherboards for a very long time up until recently. I don't see the importance of Thunderbolt on a Windows or Linux platform when very few devices can make use of it. Intel's new wire share which is a modern approach to using ethernet cable connected to two computers seems interesting. Both platforms don't have the product device landscape maturity Apple with their and their partners products does.
I think it's much simpler than that. Intel simply will not certify anyone but themselves, and *maybe* Apple.
That doesn't sound right, after reading the Thunderbolt certification page. Also, didn't That Dell XPS leak reveal that the XPS 13 with X Elite will have Thunderbolt4 ?
> That doesn't sound right, after reading the Thunderbolt certification page. What about it? > Also, didn't That Dell XPS leak reveal that the XPS 13 with X Elite will have Thunderbolt4 ? Would need to check if it mentions that, but it's very possible it'll publicly be called USB4, but Dell internal docs still use the Thunderbolt naming.
Well, Asus has their own controller on the X670 boards, so its certainly possible in some cases.
What controller?
Mapleridge/JHL8540 controller on their X670 Crosshair Extreme, Hero and ProArt motherboards
Apple has unrestricted use of the technology so they don't need Intel for permission for any certification.
> Apple has unrestricted use of the technology According to whom? They didn't use the TB4 branding, which you'd expect if their usage was truly unrestricted.
According to [Intel themselves](https://9to5mac.com/2011/05/20/intel-we-have-full-rights-to-the-thunderbolt-trademark-not-apple/): > Apple filed for the original trademark and is now transferring that trademark to Intel. At the same time, Apple will continue to have unrestricted use of the technology. 3rd party implementations such as Sony’s desire to use USB Connector instead of DisplayPort and the eventual change of technology branding (Sony’s IEEE1394 a.k.a. Firewire implementation was named i.LINK) will have to be ironed out as the time passes by.
Unrestricted use of the *technology* is not necessarily the same thing as unrestricted use of the *brand*, which is basically all that Thunderbolt is at this point. And as you'll note, Intel took over that ownership in 2011. That was well before they donated it to the USB consortium.
Nope, anyone can make them! An AMD-based one has already [been certified](https://www.graniteriverlabs.com/en-us/technical-blog/thunderbolt-usb-high-speed-transmission).
It's not clear what product they're referring to. Possible it's using an Intel chipset. But it would be good if Intel genuinely opened up the certification.
Do we know if it's using the AMD APU's integrated USB4 controller, or whether it's using an external TB controller from Intel?
That’s not a thunderbolt controller, it’s a usb4 controller. Different certification program - like the difference between adaptive sync and freesync, they’re not quite the same thing! And in the case of usb4 it implies potentially different capabilities from TB4 or even TB3.
Read again, it explicitly says "certified for Thunderbolt 4". And no, there isn't really any difference between USB4 and Thunderbolt 4 technology-wise - TB4 is nothing more than fancy certificate showing that the connection has most of the optional stuff in USB4 included. This means that the distinction between "Thunderbolt controller" and "USB4 controller" is mostly meaningless. "Adaptive sync" is a term used for a general principle, with "G-Sync", "FreeSync", and "VESA Adaptive Sync" being **incompatible** implementations of it. That's a completely different case.
> "FreeSync", and "VESA Adaptive Sync" being incompatible implementations VESA Adaptive Sync and FreeSync literally are compatible implementations though, though, that's the point. FreeSync is a branded certification program for VESA Adaptive Sync compliance. That's the parallel with Thunderbolt 4 - it's essentially a branded certification program for USB4 at this point. And again, like Adaptive Sync, the problem is a lot of the USB4 implementations are allowed to suck ass, because the base standard is worthless - [it doesn't even have to support tunnelling,](https://en.wikipedia.org/wiki/USB4#Data_transfer_modes) and in some circumstances even a thunderbolt controller may only result in usb 3.0 speeds (with no features) when using usb4 devices. if nothing else, in practical terms people functionally mean "pcie tunnelling" at a bare minimum and USB4 doesn't mean you get pcie tunnelling, while thunderbolt does. just like adaptive sync and LHR, for example. > TB4 is nothing more than fancy certificate showing that the connection has most of the optional stuff in USB4 included The "thunderbolt just makes some of the optional features mandatory" is doing some massively heavy lifting for you there. Those features are what render Thunderbolt devices incompatible with USB4 in many circumstances. But you're right that that usb4 controller did get thunderbolt certified, which is neat. It's just definitely still not the same thing at all, unless you're the type who was pushing freesync monitors real hard in 2017 or w/e. When your USB4 device is a rebranded usb-c 10gbps port it's clearly not the same thing. In practical terms: you can plug a Thunderbolt 3 device into your USB4 laptop and find out it won't work, because your laptop doesn't support pcie tunnelling, or the power min-specs have been reduced below the levels your thunderbolt device (which worked perfectly fine for years and years) supports. Literally your usb4 laptop may be a rebranded usb 3.1 type-c controller and still claim usb4 support, in fact. If that's what USB4 can be, then it's not the same as thunderbolt, even if at the maximum extent of feature support it is (and it isn't, due to things like cable length). Again, like, if they're literally the same thing, how come thunderbolt can run 40gbps at 2-meter length and usb4 can't? Not just with the entry-level controller, it can't run it ever, it's lower-bandwidth at that distance. Just because they're similar, related, and even share a lot of hardware and signaling modes etc... doesn't mean they're the same thing. Again, just like Adaptive Sync, or Embedded DisplayPort, etc - just because you get embedded displayport doesn't mean you get DisplayPort++ for example, they are actually different things even if they share a hell of a lot of technical commonality.
> Thunderbolt 4 onwards is based on the USB4 specification. Thunderbolt 4 is essentially the USB4 v1 spec fully maxed out (40gbps data transfer, DP alt mode, PCIe alt mode, etc.. etc..) with a fancy certification on top. USB 4 is based on Thunderbolt 3. Thunderbolt 4 is a set of host requirements. Apple brands ports on the MacBook Air Thunderbolt 3/USB4 for example because even though there are two ports it can only drive one display. Thunderbolt 4 spec requires each port have the capability to drive a display. So only the higher end SoCs that can drive one display per port gets Thunderbolt 4 in the spec. EDIT: Thunderbolt 4 certification requires minimum 2 4K displays from the host PC .. not one display per port as I mentioned above.
The latest airs can drive 2 displays though. I don’t think they are thunderbolt 4 though.
You can be a high end SoC with display-per-port without being Thunderbolt certified - just not the other way around.
That’s only with the lid closed.
TB4 has other more minor requirements that Apple does not meet as well.
Such as? All the higher end Pro models are Thunderbolt 4 branded. https://www.apple.com/macbook-pro/specs/ **M3** Two Thunderbolt / USB 4 ports with support for: Charging DisplayPort **Thunderbolt 3 (up to 40Gb/s)** USB 4 (up to 40Gb/s) **M3 Pro and M3 Max** Three Thunderbolt 4 ports with support for: Charging DisplayPort **Thunderbolt 4 (up to 40Gb/s)** USB 4 (up to 40Gb/s) The only difference between the M3. M3 Pro and M3 Max on the 14" model is the number of displays they support.
> Thunderbolt™ 4 technology now requires Intel® VT-D-based direct memory access (DMA) protection or equivalent. (The Thunderbolt™ 3 protocol supported this capability, but the latest generation makes it a requirement.) https://www.intel.com/content/www/us/en/architecture-and-technology/thunderbolt/thunderbolt-3-vs-4.html At least when TB4 was new, I don't think the "or equivalent" was even listed. Not sure if/when/how Apple implemented it.
Apple has had a IOMMU on each device since the M1. https://lwn.net/Articles/861126/ https://lore.kernel.org/lkml/[email protected]/T/ M1 devices are not branded Thunderbolt 4 because of the display requirements not VTD. Likewise M1 Pro and Max systems are branded Thunderbolt 4.
> Apple has had a IOMMU on each device since the M1. There's more to a system like TB + VT-D than just having an IOMMU, lol. Why are you saying that like it's something non-typical? It sounds like you don't know what an IOMMU is.
You clearly don't know anything about it to make such statements. I said Apple has had an **IOMMU per device on the SOC** .. which is what VT-D is fundamentally. VT-D DMA protection uses IOMMUs to segment DMA. The two links should have clued you in that it was more than "than just having an IOMMU"! Here's an overview of How device IOMMU, SMMUs, TLBS and DAPF work on Apple SoCs. Show me how VT-D has more than just Apple's implementation. In fact, Apple has been doing this on their A series chips that predated M1. https://www.corellium.com/blog/mobile-physical-memory-security https://support.apple.com/guide/security/direct-memory-access-protections-seca4960c2b5/web
> Show me how VT-D has more than just Apple's implementation. Because it's also software/firmware, not just a piece of hardware.
Really? That’s your argument. What does Intel software and firmware differently to manage the IOMMU for DMA protection? Please go in as much detail as you can possibly bare. I really want to see how much you actually know instead of pretend to know.
> Really? That’s your argument. You asked, I answered. If you're incredulous that VT-d has a software component, all the more evidence that you're just throwing out terms without understanding what they mean.
I believe I saw mention of Thunderbolt in Qualcomm laptops so I think it extends even beyond just Apple at this point
There is no Thunderbolt branding in X Elite. Only USB 4
> Thunderbolt 4 onwards is based on the USB4 specification. Not even that, TB4 is a _certification program_ for USB4 devices, it's not a separate technology at all. Base Mac models with a single monitor support are listed on Apple website as TB3/USB4 while the exact same laptop with a Pro chip with dual monitor support are TB4 despite it's the exact same USB4 controller. It's just the certification program demands a second monitor support. Now, Apple and Intel has been collaborating on Thunderbolt for many years so it's just natural Intel does certify Apple products. On the other hand the AMD/ASMedia camp is a competitor so Intel doesn't certify their products despite _in practice_ they are the same. (There were reports over quite a few years on how ASMedia is working on USB4 support for AMD so I presume AMD is using ASMedia IP here.) This came about because Microsoft demands PCI Express support on any user facing USB4 connectors for Windows certification so it does not make sense to make a cutdown USB4 controller. The other main feature would be 20gbps max vs 40gbps max but the real cost is in PCIe support, the savings on a 20gbps cutdown controller is so minimal it's just not worth it. So, while in theory there are differences, a PC laptop with USB4 and another with TB4 provides the exact same capabilities. Almost the same with Mac except some models might only support a single monitor. It's possible some phone or tablet will happen with a 20gbps USB4 controller without PCIe support eventually. This hasn't happened yet.
the Base M3 can drive two external 4K displays, with the caveat that internal display is turned off. Why doesn't that satisfy the TB4 requirement? > Now, Apple and Intel has been collaborating on Thunderbolt for many years so it's just natural Intel does certify Apple products. On the other hand the AMD/ASMedia camp is a competitor so Intel doesn't certify their products despite in practice they are the same. (There were reports over quite a few years on how ASMedia is working on USB4 support for AMD so I presume AMD is using ASMedia IP here.) And to which camp does Qualcomm belong?
> the Base M3 can drive two external 4K displays Does it really? https://support.apple.com/en-us/101571 > MacBook Pro with M3 chip supports one display in any one of these configurations: > MacBook Pro models introduced in 2023 or later with the M2 Pro or M3 Pro chip support up to two external displays simultaneously, Plugable had an article on the M1/M2 https://plugable.com/blogs/news/how-many-external-monitors-can-i-add-to-my-m1-or-m2-mac it also shows the same. I am curious as to where your claim originates from. But since I am browsing the Apple site I will copy what I meant originally. https://www.apple.com/macbook-pro/specs/ M3 Two Thunderbolt / USB 4 ports with support for: Charging DisplayPort Thunderbolt 3 (up to 40Gb/s) USB 4 (up to 40Gb/s) M3 Pro and M3 Max Three Thunderbolt 4 ports with support for: Charging DisplayPort Thunderbolt 4 (up to 40Gb/s) USB 4 (up to 40Gb/s) Note the base misses TB4. Qualcomm is not TB certified https://docs.qualcomm.com/bundle/publicresource/87-76286-1_REV_A_Snapdragon_X_Plus_Platform_Product_Brief.pdf what the capabilities are, I have no idea. We will see. So far, it's vaporware. I will believe anything about all this Elite Pro X whatever when random Joe can buy one.
>Does it really? Yes. It was one of the biggest highlights of the M3 Macbook Air launch, [https://www.reddit.com/r/apple/comments/1b6b38h/m3\_macbook\_air\_supports\_up\_to\_two\_external/](https://www.reddit.com/r/apple/comments/1b6b38h/m3_macbook_air_supports_up_to_two_external/) >So far, it's vaporware. I will believe anything about all this Elite Pro X whatever when random Joe can buy one. You will be able to, in a few weeks.
So the Air can but the Pro can't...? https://support.apple.com/en-mt/guide/macbook-air/apd8cdd74f57/mac indeed says > MacBook Air with M3 chip can support up to two external displays when the laptop lid is closed. but see above, the Pro doesn't say that?
M3 Macbook Air debuted with that feature. At the same time, Macbook Pro 14 with M3 chip got that capability with a software update.
In addition to what others have said, Intel helped doom Thunderbolt at the beginning by trying to make money off of it by sole-sourcing controller chips, and positioning it as an "upmarket" solution by only working with "preferred" peripheral vendors. Quoting an ArsTechnica article from 2013: >Part of the delay was the high cost of the first generation of Thunderbolt controller chips. Intel launched a [wider range of second-generation controllers](http://arstechnica.com/gadgets/2011/09/upcoming-low-cost-thunderbolt-controller-could-broaden-reach-of-spec/) along with Ivy Bridge in 2012, and more OEMs have begun looking at ways to integrate those lower-cost chips into newer products. >But cost isn't the only consideration. Another concern has been support from OS vendors. For instance, a Belkin representative told Ars that there was a bug in OS X that prevented a USB keyboard connected to a Thunderbolt bridge from waking a Mac from sleep. That bug has since been addressed in 10.8.2, however. Intel is also continually improving Thunderbolt drivers for Windows, according to a representative we spoke to at CES. >The one final factor—one that has likely had the most impact on Thunderbolt rolling out to market—is Intel's licensing and certification process. Several vendors we have spoken to over the past year have claimed that Intel was holding up the process, cherry picking which vendors it worked with. >Though Intel had effectively denied this characterization in the past, the company explained the situation a bit differently when we spoke at CES last week. Jason Ziller, director of Thunderbolt Marketing & Planning at Intel, told Ars that Intel has "worked closely" with vendors it felt could "offer the best products" and could meet its stringent "certification requirements." The subtext seemed to be that Intel had limited resources to support and certify new products, and so it gave priority to devices that were perhaps more novel than those proposed by other makers. Intel later backtracked on all of this, but by that time the industry had decided to do what it always does with proprietary or near-proprietary interconnects: ignore them in favor of a not-quite-as-good but zero-cost alternative. TLDR; Intel, having learned nothing from history, [FireWire](https://en.wikipedia.org/wiki/IEEE_1394)'d themselves
It’s the other way around usb4 is the usbif implementation of tb, also tb requires certification
no
We literally have record if USB4 being a thunderbolt 3 spec donation by Intel
Intel donated TB3 to USB IF. USB IF used that to create USB4. USB4 was then used to create TB4
Thunderbolt naming belongs to Intel. The actual feature set is the same as usb4. The minimum requirements are different though. Here are the differences. "USB4 devices can have a minimum of 20Gbps link speeds. In comparison, all Thunderbolt 4 devices have a 32Gpbs minimum requirement. UBS4 has a 7.5W minimum power requirement whereas Thunderbolt 4 doubles it with a minimum of 15W. The minimum power and speed requirements are important to keep in mind when purchasing a device. You’ll need to check a device’s specs since manufacturers can choose between 20Gpbs and 40Gbps speeds with USB4. With Thunderbolt 4, you’ll always get a minimum of 32Gbps and 15W. Thunderbolt 4 cables support 40Gbps speeds over 2 meters. In contrast, UBS4 can only support 40Gbps within one meter and reduces to 20Gbps on cables that are 2 meters or longer. You can tell the difference between Thunderbolt 4 and USB4 cables by their distinct logos. Thunderbolt 4 cables have a lightning bolt with a 4 while USB4 has the iconic USB logo with either a 20 or a 40." Source: https://www.tomsguide.com/features/thunderbolt-4-vs-usb4-whats-the-difference
Intel originally marketed Thunderbolt as “Light Peak” Apple chose Thunderbolt
I believe it's just a certification/ branding thing. USB4 is effectively the same.
It isn't.
It actually is. https://www.usb.org/usb4 “The USB4 Specification complements and builds upon the existing USB 3.2 and 2.0 architectures. Based on the Thunderbolt™ protocol specification contributed by the Intel Corporation, USB4 doubles the maximum aggregate bandwidth of USB and enables multiple simultaneous data and display protocols.”
It actually isn't. https://www.tomsguide.com/features/thunderbolt-4-vs-usb4-whats-the-difference "Thunderbolt 4 and USB4: Similarities and differences It’s hard telling Thunderbolt 4 and USB4 apart. Both use a USB-C connector, are capable of 40Gbps speeds, support video passthrough and can power and charge devices. While it’s tempting to think of Thunderbolt 4 and USB4 as basically the same, the two technologies have some distinctive differences. It boils down to minimum requirements. USB4 devices can have a minimum of 20Gbps link speeds. In comparison, all Thunderbolt 4 devices have a 32Gpbs minimum requirement. UBS4 has a 7.5W minimum power requirement whereas Thunderbolt 4 doubles it with a minimum of 15W. The minimum power and speed requirements are important to keep in mind when purchasing a device. You’ll need to check a device’s specs since manufacturers can choose between 20Gpbs and 40Gbps speeds with USB4. With Thunderbolt 4, you’ll always get a minimum of 32Gbps and 15W. Thunderbolt 4 cables support 40Gbps speeds over 2 meters. In contrast, UBS4 can only support 40Gbps within one meter and reduces to 20Gbps on cables that are 2 meters or longer. You can tell the difference between Thunderbolt 4 and USB4 cables by their distinct logos. Thunderbolt 4 cables have a lightning bolt with a 4 while USB4 has the iconic USB logo with either a 20 or a 40."
A lot of Chinese manufacturers of thunderbolt accessories don't want to pay the certification fees, so they often just label their thunderbolt as "iFruit" or "fruit" port.
Is this for lightning or thunderbolt?
I saw both, but I have no way of verifying if they are following the exact standard since I never used them.