Optical Thunderbolt 3 Cables Begin Rolling Out in Lengths Up to 50 Meters

[jimthing]

Does anyone think these cables are rather gimped from their release?

They already do not support:

1. 6K displays (i.e. basically only Apple XDR, at this point; only outputting 5K resolution on them).
2. Thunderbolt 4 (+ interrelated USB4) are around the corner (6-9 mths), with a load of new "Alternate modes".

Given the increase in pricing over the optical TB2 cables too, is it really worth buying these near their supersession by the next TB4 standard?
...It's kind of too little too late at this stage. 🙄

 

[jimthing]

PSA: CalDigit have released their active 2m Thunderbolt 4 cable ($80).

https://www.caldigit.com/thunderbolt-4-usb-4-cable
These ones are among the first ones released, and are almost identical to their TB3 ones, offering full 40Gb, 100W Power Delivery.

Question most will wonder is:
What are all the spec differences between the best 2m length active TB3 vs TB4 cables? (CalDigits site doesn't make it completely clear on something like a table, unfortunately.) So AFAICT, the differences are the following:


1. TB4 ones offer so-called 'universal' compatibility with all USB speeds (including upcoming 40Gb vanilla USB4).
TB3 active 2m TB3 cables in USB-mode only do 0.5Gb USB 2 speed. No more guessing max speed!

2. TB4 support all/most alt-modes. Potentially very useful as no more guessing if the cable will do anything!

3. TB4 ones do 100W power delivery over both TB3/4 and vanilla USB-C connections. Whereas TB3 ones only do 100W over TB3/4 connections.

4. TB4 ones do up to 1x 8K display at 60Hz. TB3 can't do 8K displays at all, but do up to 1x 5K/6K display at 60Hz.

5. TB4 ones minimum spec required is PCIe 3.0 at 32Gbps, thus 3GBps (that's bytes not bits!) maximum connection speeds. TB3's minimum spec required was PCIe 3.0 at 16Gbps, but can also optionally do 32Gbps.

6. TB4 ones offer Intel VT-d DMA protection, for data security, but TB3 ones don't. (Google it!)

7. (unconfirmed?) TB4 ones support upcoming 4x TB4 port docks, but TB3 ones don't (guessing due to point 4 PCIe issue, above?).

8. (unconfirmed?) TB4 ones have a smaller connector on each end of the cable, if that's important to you.


In table form:

	TB4	TB3
1. USB speeds	all, up to 40Gb	up to 0.5Gb (USB 2.0)
2. Alt-modes	all	some
3. 100W max PD	TB3/4 and USB-C devices	TB 3/4 devices only
4. Displays (max.)	1x 8K 60Hz	1x 5/6K 60Hz
5. Data connection (min.)	PCIe 3.0 32Gbps	PCIe 3.0 16Gbps (32Gbps optional)
6. Intel VT-d DMA protection	yes	no
7. 4x TB4 port dock support	yes	no
8. Cable connector smaller	yes	no

..................

Which then comes around to the big question with optical TB3 cables, previously asked but cannot get an answer on:

What USB speeds/alt-mode options/other TB4 things do optical TB3 cables offer? Obviously they won't do the power, but do they match everything else that these new copper 2m active TB4 cables offer?

 

[jimthing]

Also found another (CHEAPER!) 10m optical TB3 cable.

Cable Matters do a Mac-only 10m one ($330), product ID: "107023-10m". Only available at 10m length. Is this new?:
https://www.cablematters.com/pc-128...et-not-compatible-with-windows-computers.aspx


Compatibility wise, it says:

"The cable does not support USB-C, DisplayPort Alt Mode, USB, or Power Delivery features. It is only compatible with Thunderbolt 3 computers and peripherals."


Weirdly the marketing info on the page also states...
"Fiber optic cable with 4 fiber cores enables long lengths not possible with traditional copper cables"
And shows an image with text "4 Fiber + 7 Copper" strands within it:

So does that mean it offers power to peripherals, or not? Given it says Power Delivery features aren't supported I'd guess not. Perhaps they mean the 7 copper strands are protective only, to strengthen the cable...?

Anyway, this cheaper $330 CM one offers the same functionalities as the more expensive $370 Corning one at the same 10m/33' length, but at a lower price ($40 less).

But the same questions remain about full TB4 functionalities with these TB3 optical cables (see red in post above!). Why can these TB3 optical cables not be made into optical TB4 cables, offering everything TB4 copper ones can (except power)?

 

[BeatCrazy]

PSA: CalDigit have released their active 2m Thunderbolt 4 cable ($80).

https://www.caldigit.com/thunderbolt-4-usb-4-cable
These ones are among the first ones released, and are almost identical to their TB3 ones, offering full 40Gb, 100W Power Delivery.

Question most will wonder is:
What are all the spec differences between the best 2m length active TB3 vs TB4 cables? (CalDigits site doesn't make it completely clear on something like a table, unfortunately.) So AFAICT, the differences are the following:


1. TB4 ones offer so-called 'universal' compatibility with all USB speeds (including upcoming 40Gb vanilla USB4.2).
TB3 active 2m TB3 cables in USB-mode only do 0.5Gb USB 2 speed. No more guessing max speed!

2. TB4 support all/most alt-modes. Potentially very useful as no more guessing if the cable will do anything!

3. TB4 ones do 100W power delivery over both TB3/4 and vanilla USB-C connections. Whereas TB3 ones only do 100W over TB3/4 connections.

4. TB4 ones do up to 1x 8K display at 60Hz. TB3 can't do 8K displays at all, but do up to 1x 5K/6K display at 60Hz.

5. TB4 ones minimum spec required is PCIe 3.0 at 32Gbps, thus 3GBps (that's bytes not bits!) maximum connection speeds. TB3's minimum spec required was PCIe 3.0 at 16Gbps, but can also optionally do 32Gbps.

6. TB4 ones offer Intel VT-d DMA protection, for data security, but TB3 ones don't. (Google it!)

7. (unconfirmed?) TB4 ones support upcoming 4x TB4 port docks, but TB3 ones don't (guessing due to point 4 PCIe issue, above?).

8. (unconfirmed?) TB4 ones have a smaller connector on each end of the cable, if that's important to you.


In table form:

	TB4	TB3
1. USB speeds	all, up to 40Gb	up to 0.5Gb (USB 2.0)
2. Alt-modes	all	some
3. 100W max PD	TB3/4 and USB-C devices	TB 3/4 devices only
4. Displays (max.)	1x 8K 60Hz	1x 5/6K 60Hz
5. Data connection (min.)	PCIe 3.0 32Gbps	PCIe 3.0 16Gbps (32Gbps optional)
6. Intel VT-d DMA protection	yes	no
7. 4x TB4 port dock support	yes	no
8. Cable connector smaller	yes	no

..................

Which then comes around to the big question with optical TB3 cables, previously asked but cannot get an answer on:

What USB speeds/alt-mode options/other TB4 things do optical TB3 cables offer? Obviously they won't do the power, but do they match everything else that these new copper 2m active TB4 cables offer?

Confirming no smaller end on TB4 cables, at least for the Cable Matters version I have.

 

[jimthing]

Confirming no smaller end on TB4 cables, at least for the Cable Matters version I have.View attachment 1731912

Interesting, thanks.

Presumably the TB4 cable is a 2m CM one, and is the TB3 cable is also a 2m length CM one, or not?

CM one here:

[Intel Certified] 40Gbps Thunderbolt 4 USB C Cable with 100W Charging

Active [Intel Certified] Thunderbolt 4 Cable is the most advanced and one of the longest Thunderbolt cables available today.

www.cablematters.com

The TB4 one looks identical to the CalDigit in some ways ("100W" printed on the cable itself), but the CalDigit images on their site make their connector look smaller:
http://shop.caldigit.com/uk/index.php?route=product/product&path=84_72&product_id=208

They could simply be renders though...?

 

[BeatCrazy]

Interesting, thanks.

Presumably the TB4 one is a 2m CM one, and is the TB3 one the same brand at 2m length?

CM one here:

[Intel Certified] 40Gbps Thunderbolt 4 USB C Cable with 100W Charging

Active [Intel Certified] Thunderbolt 4 Cable is the most advanced and one of the longest Thunderbolt cables available today.

www.cablematters.com

Correct on the TB4 version. The TB3 is of unknown origin to me, but it is only .8m. There is no branding on the other side. I'm struggling to recall where I got it. I know it's not from CalDigit, Razer, or Belkin.

 

[jimthing]

Correct on the TB4 version. The TB3 is of unknown origin to me, but it is only .8m. There is no branding on the other side. I'm struggling to recall where I got it. I know it's not from CalDigit, Razer, or Belkin.

Thanks again.

That means the 0.8m TB3 one is passive, hence has a smaller connector compared to 2m active ones. So the question of whether active 2m TB4's connectors are smaller than active 2m TB3's is still in the air.

 

[BeatCrazy]

Thanks again.

That means the 0.8m TB3 one is passive, hence has a smaller connector compared to 2m active ones. So the question of whether active 2m TB4's connectors are smaller than active 2m TB3's is still in the air.

Well all you had to do was ask

Cable Matters 2m active TB4 cable vs Belkin 2m active TB3 cable (right).

 

[jimthing]

Well all you had to do was ask

Cable Matters 2m active TB4 cable vs Belkin 2m active TB3 cable (right).
View attachment 1731963

Haha, that's that answered then! Changed the table above back again...

8. Cable connector smaller: yes

 

[BeatCrazy]

Haha, that's that answered then! Changed the table above back again...

8. Cable connector smaller: yes

As long as you qualify it with "when compared to 2m active TB3" cable

Also, I can confirm that Apples 2m TB3 Pro Cable (which behaves just like a TB4 cable AFAIK) also has a smaller connector than a 2m Belkin active TB3 cable, yet it's about 10% longer than my Cable Matters 2m TB4 cable.

So from smallest to largest connector, based on the various ones I have around:

1) .8m passive
2) 2m TB4
3) 2m TB3 Apple Pro
4) 2m TB2 active

 

[jimthing]

As long as you qualify it with "when compared to 2m active TB3" cable

Also, I can confirm that Apples 2m TB3 Pro Cable (which behaves just like a TB4 cable AFAIK) also has a smaller connector than a 2m Belkin active TB3 cable, yet it's about 10% longer than my Cable Matters 2m TB4 cable.

So from smallest to largest connector, based on the various ones I have around:

1) .8m passive
2) 2m TB4
3) 2m TB3 Apple Pro
4) 2m TB2 active

What makes Apple's TB3 2m active cable worth ~double the price ($130) of TB4 ones of the same 2m length?
https://www.apple.com/shop/product/MWP32AM/A/thunderbolt-3-pro-cable-2-m

Sure it's braided, but the only other thing different to active TB4 cables is this "DisplayPort video output (HBR3)", which AFAIU is essentially DP 1.3 (whereas I think most (all?) other active TB3 cables are only DP 1.2), with active TB4 ones being DP 1.4 (as they support 8K's)?

Apple's KB specs article for their cable is 'limited', as per usual with Apple:
https://support.apple.com/en-gb/HT210997

Of course, they did release their cable in June 2020 and is arguably more fancy (braiding, wow!), and these TB4 active ones are were now released ~7-8 months later, offering more functionality. But I bet Apple don't lower their pricing.

Oh, looks like the main news thread has picked this up today too (which you're in already!):

CalDigit and OWC Unveil Thunderbolt 4 and USB 4 Cables

Popular Mac accessory makers CalDigit and OWC have today announced new all-in-one Thunderbolt 4 and USB 4 cables, promising maximum data and power...

www.macrumors.com

 

[BeatCrazy]

What makes Apple's TB3 2m active cable worth ~double the price ($130) of TB4 ones of the same 2m length?

Because up until a few days ago, the Apple cable was the only 2m TB3 cable in the entire world that also supported USB 3.1 speeds

I don't know how to test DP1.3 functionality of the Apple TB3 Pro cable to confirm it's essentially the same as a TB4 cable. @joevt might have insight into if HBR3 can be carried over the Apple TB3 Pro cable.

EDIT - on Apple's on support page, they indicate that their TB3 Pro cable does support HBR3, so I suppose that confirms it's really a TB4 cable. https://support.apple.com/en-gb/HT210997

Also, Apples TB3 Pro cable does not have the "3" logo on it, only the "bolt". Even more evidence you can use it as a TB4 cable

 

[jimthing]

Also, Apples TB3 Pro cable does not have the "3" logo on it, only the "bolt". Even more evidence you can use it as a TB4 cable

I bet this surreptitiousness on Apple's part, is due to them not having any Macs yet that can do the full TB4 standard. So they didn't add any number to it, accordingly.
When they release Macs that do (maybe the next M-series ones), we'll have to see what they call it then, as if it's truly TB4, why wouldn't they update the marketing to say so?

 

[joevt]

4. TB4 ones do up to 1x 8K display at 60Hz. TB3 can't do 8K displays at all, but do up to 1x 5K/6K display at 60Hz.

There's no difference in 8K support between a TB3 and TB4 cable (except what I say below about HBR3). For 8K 60Hz you need DisplayPort 1.4 and DSC and 8K resolution support from the GPU and drivers.

5. TB4 ones minimum spec required is PCIe 3.0 at 32Gbps, thus 3GBps (that's bytes not bits!) maximum connection speeds. TB3's minimum spec required was PCIe 3.0 at 16Gbps, but can also optionally do 32Gbps.

This has nothing to do with the cable. This is talking about how the Thunderbolt controller is connected to the PCIe bus. In either case you need a 40 Gbps for full bandwidth a Thunderbolt controller connected as PCIe 3.0 x2 (15.75 Gbps) or PCIe 3.0 x4 (31.5 Gbps) can still fill the rest of the 40 Gbps bandwidth with DisplayPort. If Thunderbolt could do 31.5 Gbps of data, then one would expect something like 3500 MB/s but the max is around 3000 MB/s (24 Gbps).

6. TB4 ones offer Intel VT-d DMA protection, for data security, but TB3 ones don't. (Google it!)

Not a function of the cable.

7. (unconfirmed?) TB4 ones support upcoming 4x TB4 port docks, but TB3 ones don't (guessing due to point 4 PCIe issue, above?).

Not a function of the cable. You can use 4 port docks (actually 1 upstream port and 3 downstream ports) even with Thunderbolt 2 Macs.

8. (unconfirmed?) TB4 ones have a smaller connector on each end of the cable, if that's important to you.

TB4 cables are high quality enough to not require being active - so space is not needed for the active chipset.

What USB speeds/alt-mode options/other TB4 things do optical TB3 cables offer? Obviously they won't do the power, but do they match everything else that these new copper 2m active TB4 cables offer?

Optical cables are active (to convert copper to optical) and can't support all the timings (without adding even more cost?)
20.625 Gbps Thunderbolt 3/4
20 Gbps USB4 40
10.3125 Thunderbolt 1/2
10 Gbps USB 3.1 gen 2, USB4 20
8.1 Gbps HBR3
5.4 Gbps HBR2
5 Gbps USB 3.0
2.7 Gbps HBR
1.62 Gbps RBR

What makes Apple's TB3 2m active cable worth ~double the price ($130) of TB4 ones of the same 2m length?
https://www.apple.com/shop/product/MWP32AM/A/thunderbolt-3-pro-cable-2-m

Sure it's braided, but the only other thing different to active TB4 cables is this "DisplayPort video output (HBR3)", which AFAIU is essentially DP 1.3 (whereas I think most (all?) other active TB3 cables are only DP 1.2), with active TB4 ones being DP 1.4 (as they support 8K's)?

Apple's KB specs article for their cable is 'limited', as per usual with Apple:
https://support.apple.com/en-gb/HT210997

Of course, they did release their cable in June 2020 and is arguably more fancy (braiding, wow!), and these TB4 active ones are were now released ~7-8 months later, offering more functionality. But I bet Apple don't lower their pricing.

Oh, looks like the main news thread has picked this up today too (which you're in already!):

CalDigit and OWC Unveil Thunderbolt 4 and USB 4 Cables

Popular Mac accessory makers CalDigit and OWC have today announced new all-in-one Thunderbolt 4 and USB 4 cables, promising maximum data and power...

www.macrumors.com

I bet this surreptitiousness on Apple's part, is due to them not having any Macs yet that can do the full TB4 standard. So they didn't add any number to it, accordingly.
When they release Macs that do (maybe the next M-series ones), we'll have to see what they call it then, as if it's truly TB4, why wouldn't they update the marketing to say so?

Where does it say the Apple Thunderbolt 3 Pro Cable is active? Does this cable not do all the things a Thunderbolt 4 cable can? Maybe Apple didn't call it Thunderbolt 4 because the certification didn't exist yet?

I don't know how to test DP1.3 functionality of the Apple TB3 Pro cable to confirm it's essentially the same as a TB4 cable. @joevt might have insight into if HBR3 can be carried over the Apple TB3 Pro cable.

There's two ways to send HBR3 over a cable - tunnelled as Thunderbolt (in that case, any 40 Gbps cable can do that) or as actual DisplayPort (I guess some active Thunderbolt 3 cables cannot do that?).
To claim TB4 cable status - you need to support both methods. In that case, you need a non-Thunderbolt dock or display with USB-C input and a display that can use HBR3. The CalDigit SOHO with a DisplayPort 1.4 display should be sufficient (it will test only two lanes - not all four). If you have a Titan Ridge based dock or display, then to test HBR3 connection you need to connect it to a non-Thunderbolt port such as a USB-C port of a GPU like the W5700. Use the AGDCDiagnose command to see what the connection link rate and link width. With 4 lanes, HBR3 is 4K 120Hz. HBR2 is 4K 60Hz. HBR is 1440p60. RBR is 1080p60. With 2 lanes, use lower refresh rates or resolutions.

 

[jimthing]

Note Linus Tech has just released a new video, but doesn't really say anything about why these optical cables are still TB3 and not now TB4.

Which is one reason why he has to plug it into a TB3 dock to get the functionality he's explaining, whereas presumably if it was TB4 it could do all that natively already without the dock.

 

[joevt]

Note Linus Tech has just released a new video, but doesn't really say anything about why these optical cables are still TB3 and not now TB4.

I guess it may be timing issues. TB4 supports USB4 which has different timing (20 Gbps) than Thunderbolt (20.625 Gbps).
The cable also doesn't do USB 1.1 (1.5, 12 Mbps), USB 2.0 (480 Mb/s), USB 3.x (5 or 10 Gbps) or DisplayPort (1.62, 2.7, 5.4, 8.1 Gbps - multiples of 0.27 Gbps).

USB4 support doesn't matter since there don't exist any USB4 devices yet. Thunderbolt 4 hubs and docks support USB tunnelling which is a new feature introduced with USB4. They should work if they are connected using Thunderbolt timing to the optical cable.

Which is one reason why he has to plug it into a TB3 dock to get the functionality he's explaining, whereas presumably if it was TB4 it could do all that natively already without the dock.

The dock was required for the bus-powered Thunderbolt storage device. Any Thunderbolt device that is not bus-powered should be able to connect directly to the cable.

TB4 optical cables are planned by Intel but I don't know when they'll exist. https://newsroom.intel.com/wp-conte...ntel-thunderbolt4-announcement-press-deck.pdf

 

[jimthing]

I guess it may be timing issues. TB4 supports USB4 which has different timing (20 Gbps) than Thunderbolt (20.625 Gbps).
The cable also doesn't do USB 1.1 (1.5, 12 Mbps), USB 2.0 (480 Mb/s), USB 3.x (5 or 10 Gbps) or DisplayPort (1.62, 2.7, 5.4, 8.1 Gbps - multiples of 0.27 Gbps).

USB4 support doesn't matter since there don't exist any USB4 devices yet. Thunderbolt 4 hubs and docks support USB tunnelling which is a new feature introduced with USB4. They should work if they are connected using Thunderbolt timing to the optical cable.


The dock was required for the bus-powered Thunderbolt storage device. Any Thunderbolt device that is not bus-powered should be able to connect directly to the cable.

TB4 optical cables are planned by Intel but I don't know when they'll exist. https://newsroom.intel.com/wp-conte...ntel-thunderbolt4-announcement-press-deck.pdf

So to be clear, these optical TB3 cables only do TB3. They do none of the TB4 functions –likely due to those timings you mentioned– (unless a dock is used):
- no direct USB 1/2/3/4.
- no DP HBR 3.

While there's no USB4 stuff right now and little TB4, there will be in the near future, and that's my point: buying them now, these expensive optical TB3 cables are immediately limited in their scope of usability going forward, as they'll be stuck at those TB3 limitations forever.

This is a major oversight IMO, in how they have been released. They've finally released for sale these optical TB3 cables, at the same time that TB4 (and its associated USB4 and backwards USB1/2/3 + DP functionalities) is rolling out. Making 'buying into' these older gen protocol optical cables a very limited prospect for many users given their high cost.

It doesn't take a lot of imagination to suspect many users are looking to buy one of the upcoming higher spec'd bigger M-series MBPs or iMacs (likely with full TB4 support), who then shortly afterwards want to buy either TB4 or USB4 peripherals (eg. storage), and a long cable to go with it. Yet this one won't cut it for many of these uses directly, without some kind of hub between them – for even more expense and hassle.


"Targeting ~5-50m [Future]" is used in Intel's TB4 brochure, which while nice to know, could mean another whopping 5 years or something (like it was until these optical TB3 ones came along! – in Apple-land, TB3 came Nov.2016 on the MBP15 I actually bought at the time).

Ultimately, that makes it a difficult sell for optical TB3 cables, when everyone knows TB4 exists and these cables do not support any of TB4 functionalities going forward.
Its lifespan is already limited from the day you buy it –it could be next month, next year, or in 5 years (you won't know when buying it!) when a TB4 variant is released– hardly a good selling tactic for such expensive cables.

"Hello here's our new long amazing optical TB3 cables. Erm, cough, no, they don't do any of the of the new TB4 functions just arriving now. But they're really good otherwise, honest!" ...wow, I simply must buy one then (not).

 

[joevt]

It doesn't take a lot of imagination to suspect many users are looking to buy one of the upcoming higher spec'd bigger M-series MBPs or iMacs (likely with full TB4 support), who then shortly afterwards want to buy either TB4 or USB4 peripherals (eg. storage), and a long cable to go with it. Yet this one won't cut it for many of these uses directly, without some kind of hub between them – for even more expense and hassle.

All true. But consider these cables are super expensive so adding a hub or two that can make the cable work with USB4 (non Thunderbolt) hosts or devices (if or when they exist) maybe a reasonable compromise or at least a necessary compromise (you work with what you have).

 

[jimthing]

All true. But consider these cables are super expensive so adding a hub or two that can make the cable work with USB4 (non Thunderbolt) hosts or devices (if or when they exist) maybe a reasonable compromise or at least a necessary compromise (you work with what you have).

Yeah sure, you use what you can get, as ever I suppose.

It just smacks of lunacy how long these TB3 optical cables have taken to get to market, only to be superseded in short order with a new version of the protocol with considerable advantages many would want.

 

[jimthing]

Next-Gen Thunderbolt Could Double Speed of TB4, Intel Says

Thunderbolt 5 could be up to 80 Gbps.

www.tomshardware.com

Read the above rather boring filler article about TB5, featuring an Intel exec making the pretty unsurprising comment that v5 of the protocol would likely double the speed to 80Gbps (like, who knew we'll need that, right!).

Anyway, more importantly, the article mentioned this:

And for those with the need, Thunderbolt 4 cables up to 50m (164 feet) long should be available around next year.

So if anyone wants to buy-in to optical TB3 cables now go ahead, but TB4 variants may or may not exist "around next year" – which more than likely will end-up meaning mid-late 2023, no doubt!