Thunderbolt 5 in New Macs: Features, Benefits, and Is It Needed?

[Tago]

The USB consortium has done a good job of becoming competitive to Thunderbolt, although the marketplace is rather a mess.

Thunderbolt made them do that. Like M-series puts the competition to work for processors. Guess there will be a while until they have to reinvent the USB C plug, thus one of the caveats with new generations of Thunderbolt is gone. For now. And boy, am I glad for that

 

[theluggage]

The USB consortium has done a good job of becoming competitive to Thunderbolt, although the marketplace is rather a mess.

The situation now is that Thunderbolt has effectively merged with USB - Thunderbolt certification and branding just requires some features and minimum specs which are "optional" in the USB specs.

Hence the "Thunderbolt/USB4" ports on M2 MacBook Pro vs. the full "Thunderbolt 4" ports on the M2 Mini - the only difference was that the Mini didn't have an internal display and could therefore support dual displays over Thunderbolt, which was the minimum required for TB4 branding.

TB4 is based on USB4 (which was based on TB3). TB5 is based on USB4v2, which added the 80Gbp mode. Both either incorporate or rely on the USB-C and USB 3.2 specs. Apart from more compulsory features, the differentiation between TB4 hubs and TB3 hubs is the multi-port TB hub and USB 3.2 tunnelling, which were added by USB4.

 

[jimthing]

What's after Thunderbolt 5?

My understanding is TB5 is likely the last of the line of external connection bus speeds for the Thunderbolt standard, as it was made to offer a maximum of 100Gbps (and TB5's 80Gbps, with 120Gbps special display mode, is basically it).

It used to have this on here, but can't find it now:
https://en.wikipedia.org/wiki/Thunderbolt_(interface)

Here's another interesting page:

List of interface bit rates - Wikipedia

en.wikipedia.org

Will we just move over to higher bandwidth unpowered optical ethernet standards (like TB was originally going to be until they changed to mainly copper, with optical being the expensive distance cable option)?

"InfiniBand GDR 12×" at 4.8Tbit/s maybe?

 

[Neodym]

How many words per minute will I be able to type on a TB5 keyboard?

Zero? Or are there any TB5 keyboards available (or keyboards with any version of TB)?

 

[jimthing]

...BTW, anyone tested speeds available using one of Corning's optical TB3 cables on TB5 Macs with a fast external?
I wonder if they still offer the TB5 speeds, even though they were originally sold for use with TB3 stuff?

I have an optical Corning 10m TB3 cable... but no TB5 devices yet to test myself.

 

[ignatius345]

One use case I bet could benefit a lot from TB5 is booting off an external drive.

 

[jimthing]

One use case I bet could benefit a lot from TB5 is booting off an external drive.

The trouble with using externals as boot drives, is Apple limit some features to their own internal boot drives.
eg. Apple Intelligence is not available if using them.

 

[constructor]

USB was one of Apple's rare wins. I called TB FireWire because Thunderbolt existed since 2011 (or 2016 with the current USB-C connector) and it still hasn't taken off.

You seem to have unrealistic expectations there if you think that Thunderbolt should or would replace USB, which will definitely never happen and has never been the idea behind it, nor with FireWire before it!

Already FireWire and then Thunderbolt had always been intended to be for peripherals needing high bandwidth at minimal latencies, and both protocols achieve exactly that, on their respective level.

And both ports have always been intended to be offered in addition to USB – with Thunderbolt even in the same physical port, but still with USB intended for most uses, and the Thunderbolt alternate mode only when actually needed.

Exactly because Thunderbolt is a lot faster than regular USB it is also more demanding to implement, but when you need what it does, you need it and you're glad it's available.

If you can slum it with USB without too many restrictions then that's okay, too – you're just not among the target audience of Thunderbolt!

 

[constructor]

It would be awesome if Asahi Linux got external eGPUs working over thunderbolt, any version. They already ship OpenGL 4.6, OpenCL 3.0, and Vulkan 1.3 drivers for Apple Silicon, so we know they don't feel constrained by Apple's support decisions. Sadly, looks like they don't have any TB or USB4 officially working at all, yet. (They also don't have M4 support, yet, but that seems to be more iterative and a matter of time.)

Apple has thrown out all the complicated and above all limiting and slowing APIs for plug-in graphics drivers exactly to optimize for Unified Memory to the massive improvements in snappiness which would have been impossible otherwise.

Linux has none of those optimizations and is still designed for the old model, so Asahi should have little problem enabling eGPUs – once they get Thunderbolt to run properly at all, that is – but they will also continue to suffer from the lagginess inherent in this driver model; That is the inherent tradeoff there.

 

[constructor]

Does anyone know yet:
(1) if a TB3/4 device is hanging anywhere along a TB5 chain, does it bring down the entire chain to TB3/4 speed?

That should only affect the devices plugged in further downstream as far as I'm aware.

(2) do the TB5 Macs have 1, 2 or 3 separate TB5 buses--are there 2 buses like before with their ports arranged like before?

All Apple Silicon SoCs have one individual Thunderbolt controller for each port, so the old Intel Mac limitations with paired ports do no longer exist with Apple Silicon.

 

[OWC_TAL]

pre-sale currently

It is now shipping as of today!

 

[Tago]

It would be awesome if Asahi Linux got external eGPUs working over thunderbolt, any version. They already ship OpenGL 4.6, OpenCL 3.0, and Vulkan 1.3 drivers for Apple Silicon, so we know they don't feel constrained by Apple's support decisions. Sadly, looks like they don't have any TB or USB4 officially working at all, yet. (They also don't have M4 support, yet, but that seems to be more iterative and a matter of time.)

Would indeed be exiting the day the kernel and subsystems becomes fully operative on M Macs. I might have a go at it if and when.. "A matter of time" consists of a lot of hope. And quite a few disappointments. At some point some distributions have to realize that they need to provide clean distros and stop throwing the entire kitchen sink at it. One distro one desktop environment, and only applications++ related to that DE. They can drop all the server stuff too, and treat desktops as desktops. Not saying all should do that, but at least a couple for each DE. They should have done that decades ago. I wished for it using S.u.S.E in the mid `90ies....

 

[OWC_TAL]

I can't believe they're still making it like this

It is actually a power requirement currently. An enclosure with a removable cable must pass certification with all cable lengths, including the very longest Thunderbolt cables (which includes active 2m+ ones yet to be even released). Longer cables have a power loss to them and thus limit the SSD that can go inside. We are already pushing the boundary on the amount of power our SSD can consume, so having a short cable means we can draw more power to the SSD, which in turn leads to better performance (and higher capacities). So having that removable cable means accounting for 1-2W of loss, even if an end user doesn't use the long cables. This is also why you will not see a 0GB Thunderbolt 5 (certified) enclosure for now, as many SSDs can require more power than available... and when not enough power, they tend to drop off or lead to data corruption.

Oh and in addition, the enclosure is IP67. No connector is rated for TB5 speeds and IP67 as well at present.

 

[OWC_TAL]

is not sold without an SSD

Sorry I don't think you will see a 0GB bus powered enclosure (at least that is Intel certified) for a while due to power draw requirements. Keep a lookout though for other stuff in the near future from us

 

[rmariboe]

No more eGPU bottleneck I guess 😃

 

[OWC_TAL]

(1) if a TB3/4 device is hanging anywhere along a TB5 chain, does it bring down the entire chain to TB3/4 speed?

No only port downstream of the TB3/4 device become TB3/4 speeds.

This is precisely why we released our Thunderbolt Hub first (https://eshop.macsales.com/shop/owc-thunderbolt-5-hub_) . Take the Thunderbolt hub and add your existing dock to a downstream port... and what you get essentially is what a TB5 dock will be.

When TB5 docks reach the market, a majority of them will not be any faster on the non-Thunderbolt ports. In fact, in ALL Thunderbolt 4 docks, all non TB ports are routed to a SINGULAR 10G USB connection. So hypothetically dock with say 18 ports versus a dock with say 11 ports have the same amount of shared bandwidth to the non TB ports. Meaning, a dock with fewer ports will actually have more bandwidth PER port than a dock with a ton.

TB brings new capabilities for PD charging speed, display support and speed on the TB ports themselves. But no real increase for anything not TB or display related. Hence if you combine a TB5 hub with a TB3/4 dock, you really get the best of both worlds.

 

[OWC_TAL]

I wonder if they still offer the TB5 speeds, even though they were originally sold for use with TB3 stuff?

No they will only operate at TB3 speeds. Those are essentially "active" cables.

 

[ThunderSkunk]

It is actually a power requirement currently. An enclosure with a removable cable must pass certification with all cable lengths, including the very longest Thunderbolt cables (which includes active 2m+ ones yet to be even released). Longer cables have a power loss to them and thus limit the SSD that can go inside. We are already pushing the boundary on the amount of power our SSD can consume, so having a short cable means we can draw more power to the SSD, which in turn leads to better performance (and higher capacities). So having that removable cable means accounting for 1-2W of loss, even if an end user doesn't use the long cables. This is also why you will not see a 0GB Thunderbolt 5 (certified) enclosure for now, as many SSDs can require more power than available... and when not enough power, they tend to drop off or lead to data corruption.

Oh and in addition, the enclosure is IP67. No connector is rated for TB5 speeds and IP67 as well at present.

Thank you for taking the time to explain that. I guess I can stop waiting for a detachable cable model.
...maybe I'll find a way to adhere my TB3 envoy to the back of the MBP's lid to keep it out of the way.

 

[platinumaqua]

You seem to have unrealistic expectations there if you think that Thunderbolt should or would replace USB, which will definitely never happen and has never been the idea behind it, nor with FireWire before it!

Already FireWire and then Thunderbolt had always been intended to be for peripherals needing high bandwidth at minimal latencies, and both protocols achieve exactly that, on their respective level.

And both ports have always been intended to be offered in addition to USB – with Thunderbolt even in the same physical port, but still with USB intended for most uses, and the Thunderbolt alternate mode only when actually needed.

Exactly because Thunderbolt is a lot faster than regular USB it is also more demanding to implement, but when you need what it does, you need it and you're glad it's available.

If you can slum it with USB without too many restrictions then that's okay, too – you're just not among the target audience of Thunderbolt!

if you go back to my original comment, it's about the lack of choices and prices of the choices available are not going down.

I've been looking for decent Thunderbolt travel docks and Thunderbolt enclosures but have not found a decent one within my price range (especially the enclosure).

There are way more USB 3.x peripherals, and more recently USB4 peripherals to choose from, but I rather get a TB certified product for guaranteed performance

 

[joevt]

...BTW, anyone tested speeds available using one of Corning's optical TB3 cables on TB5 Macs with a fast external?
I wonder if they still offer the TB5 speeds, even though they were originally sold for use with TB3 stuff?

I have an optical Corning 10m TB3 cable... but no TB5 devices yet to test myself.

TB3/4 optical cables can't do TB5 because TB5 uses PAM-3 to achieve > 40 Gbps speeds.

TB brings new capabilities for PD charging speed, display support and speed on the TB ports themselves. But no real increase for anything not TB or display related. Hence if you combine a TB5 hub with a TB3/4 dock, you really get the best of both worlds.

The issue is the choice of Thunderbolt peripheral controllers.

On the Intel side, you had Thunderbolt 4 controllers with three downstream Thunderbolt ports but only one PCIe gen 3 lane (allows only 8 Gbps of PCIe for other devices in the Thunderbolt dock).

Prior to that, you had Thunderbolt 3 controllers with one downstream Thunderbolt port and four lanes of PCIe gen 3 which allowed for multiple USB controllers that could use all of the 22 Gbps PCIe bandwidth of Thunderbolt 3 (but usually only the downstream Thunderbolt port could get full 10 Gbps USB performance since no-one bothered to use a 2 lane USB controller to get more than 8 Gbps).

There's no reason someone couldn't create a Thunderbolt 4 or 5 chip with more PCIe bandwidth. For example, ASMedia has USB4 v1 peripheral controller with PCIe gen 4 x4. It would be nice if someone made a controller with multiple downstream Thunderbolt ports and PCIe gen 4 x4 or x8.

 

[drrich2]

Remember the original iMac with USB? There was very little support for USB at the time of its release.

The way I remember the situation (your mileage may vary on my memory), Apple seemed determined to pursue their proprietary technology called GeoPort whereas USB-A was catching on fairly strongly on the PC side. I was under the impression Apple finally caved to the pressure to switch to USB, opening up Macs to more peripherals that doesn't need to be made specifically for them (then, as now, a small segment of the personal computer market).

On the Windows PC side, USB-A was catching on fairly fast.

 

[constructor]

The way I remember the situation (your mileage may vary on my memory), Apple seemed determined to pursue their proprietary technology called GeoPort whereas USB-A was catching on fairly strongly on the PC side. I was under the impression Apple finally caved to the pressure to switch to USB, opening up Macs to more peripherals that doesn't need to be made specifically for them (then, as now, a small segment of the personal computer market).

On the Windows PC side, USB-A was catching on fairly fast.

That is pretty much the opposite from how it actually happened.

PC motherboards did indeed sporadically begin to include some USB ports back then but those were badly supported and almost never used in practice.

It was the iMac which pushed USB into actual use with widespread support and usage, kicking off a spree of USB peripheral introductions where the PCs followed only belatedly, but even today they haven't actually completed that transition yet: There are still PS/2 ports on PCs to this very day!

 

[840quadra]

That is pretty much the opposite from how it actually happened.

PC motherboards did indeed sporadically begin to include some USB ports back then but those were badly supported and almost never used in practice.

It was the iMac which pushed USB into actual use with widespread support and usage, kicking off a spree of USB peripheral introductions where the PCs followed only belatedly, but even today they haven't actually completed that transition yet: There are still PS/2 ports on PCs to this very day!

Working in IT back in the late 90s I also recall the same. Geoport was a 68K protocol / feature. WAY before USB was effectively introduced in 98.

IIRC Windows 98 technically supported the serial bus before Apple did, but not many (if any) systems shipped with native ports before the iMac.

I remember completing a deployment (for the same company a year later in 1999) multiple PC workstations in a new office build. The systems where HP and everything had PS2, and parallel ports for printers, ZIP drives and other such items. Their Marketing department had iMac and B&W G3 systems. I was (initially) baffled by all of the USB devices and the new (to me) connectors.

The next year, I started seeing Compaq servers offering the same port for connecting external devices, and similarly noted more of the (higher end) PC systems that management / devs had feature a single (and more rarely), or pair of USB ports on the back.

 

[theorist9]

Of course it's needed. Otherwise you end up with Thunderbolt envy.

....though at least on the PC side, there appear to be some teething pains (which may have been due simply to a bad cable):

My first Thunderbolt 5 experience has been a huge bust

Is Thunderbolt 5 all that it's cut out to be? After putting together a Thunderbolt 5 laptop, dock, and SSD, my answer is -- for now -- a definite no.

www.pcworld.com

 

[Greybeard2017]

"InfiniBand GDR 12×" at 4.8Tbit/s maybe?

I remember InfiniBand being the future 25 years ago