Out is Light, in is Copper

Yup, you read that right: Intel Light Peak is no more and it has been replaced by the official branding of Intel Thunderbolt Technology. Love it or hate it, that is what we are going to be using for the future and now it’s time to get down to the nitty-gritty about what it does and what it can do.
We will be updating this article throughout the day with more details from the Intel press conference or when anything else crosses our path. Be sure to check back!!

Thunderbolt Technology: The Fastest Data Connection to Your PC Just Arrived


Yup, you read that right: Intel Light Peak is no more and it has been replaced by the official branding of Intel Thunderbolt Technology.  Love it or hate it, that is what we are going to be using for the future and now it’s time to get down to the nitty-gritty about what it does and what it can do. 

So here is the basic summary: Thunderbolt technology will combine both support for PCI Express based data transfers and DisplayPort technology for high resolution display outputs into a single controller and a single cable.  That cable, as we saw yesterday, basically is identical in appearance to the mini-DisplayPort connection that we have seen on graphics cards for some time now.  The connection will indeed run at 10 Gbps, making it about twice as fast (in theory) than USB 3.0, and will provide more than enough headroom for storage technologies and high speed data transfers into the future.  Users like simple answers so Intel says that you can “transfer a full-length HD movie in less than 30 seconds” and “backup 1 year of continuous MP3 playback in just over 10 minutes.”  Pretty impressive stuff.

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Technically, Thunderbolt is pretty interesting as both data and display signals will transfer over the same cable with arbitration from the controller chip.  It is a bi-directional communication that actually provides 10 Gbps of bandwidth PER PORT.  It remains backwards compatible with existing DisplayPort displays, but since those devices likely do NOT have female mini-DisplayPort connections on them, they will not facilitate the daisy-chaining required for connecting multiple devices to a single Thunderbolt connection.  Unlike what some people worried, Thunderbolt will carry some amount of power over cable, though how much hasn’t really been specified yet.

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The first iteration of Thunderbolt is using copper, electrical based connections rather than the fiber optic connections that we saw initially with the technologies release.  This likely is the reason behind the new branding (Light Peak without light?  Yeah, we’ve already gone down that road…) and was no doubt influenced by cost.  If Intel was able to get a full 10 Gbps out of the copper cables, then why not go with those cheaper options out of the gate.  The Intel information page does state that both “electrical and optical cables” are supported, and fiber cables do carry some definite advantages in signal integrity and cable span, so we might see fiber optic options sometime this year. 

The Thunderbolt controller works in much the same way as any other existing add-on controller in a PC though it has to communication with both the PCI Express bus and a DisplayPort connection.  You can see in the diagram below that while the Thunderbolt controller connects to the system via PCI Express, the DisplayPort information has to be fed in through an external chip – in this case the PCH / chipset that traditionally handles the display output work for Intel’s Sandy Bridge platform.  There is a dashed line though from a section labeled “discrete graphics” indicating that Thunderbolt will work in that configuration as well.

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Thunderbolt can work on both data streams at the same time and in both directions and it seems to get the full 10 Gbps of rated bandwidth, in each direction.  This is what gives the technology the advantage over the USB 3.0 of today. 

Besides the speed benefits, Thunderbolt technology will allow users to continue to use thinner notebooks without sacrificing potential performance of devices – though I would wager to say that USB connections aren’t much bigger and this same feat could be accomplished with it.  Intel says that Thunderbolt was designed with professional audio and video applications in mind where low latency and highly accurate time syncs are critical.  And since the technology is compatible with current DisplayPort displays, there should be a healthy stock of available displays that will support this technology today.  (At least for display output purposes…)

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Another key here is that since the Thunderbolt technology is actually extending the native PCI Express protocol, companies will be able to build devices that traditionally have only been available inside your PC as external units.  Since we are talking about native device drivers, in theory it should be as simple as plugging in the cable to really make these types of things “external”.  Imagine a high end RAID / NAS box using this technology – it would likely appear as simply another RAID controller to the PC making things like installation to external units and easy integration into workflows a breeze.

The first company to use the technology, as we expected, is Apple.  Launching a new line of MacBook Pro machines today with support for Thunderbolt, Apple is calling it “the fastest, most versatile I/O, ever” and we would tend to agree.  Apple says on its site that you can “daisy-chain as many as 6 devices, including your display.” – interesting that there appears to be a hard limit here.   Apple is putting a lot of stock into this announcement today as is evident by the pretty substantial landing page that they created for it.

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Other vendors will surely follow and Intel lists Aja, Apogee, Avid, Blackmagic, LaCie, Promise and Western Digital as partner companies that plan to support Thunderbolt technology in upcoming products.  We are eager to see what kind of implementations these, and others, come up with, and how we’ll see it become available to non-Mac users.  Add in card perhaps?  Motherboard integrations?

We will be updating this article throughout the day with more details from the Intel press conference or when anything else crosses our path.  Be sure to check back!!

Update 1
It looks like Intel did develop the technology completely on their own but that they and Apple “collaborated to bring to market the Thunderbolt electrical solution shown today.”  We may indeed have Apple to thank for the first version of Thunderbolt and to blame for the decision to use to mini-DisplayPort connectors.

Update 2
We have just a bit more detail on the technical nature of the architecture.  It is indeed 10 Gbps per channel and it is fully bidirectional.  While it currently supports PCIe and DisplayPort protocols, Intel is stating that “other configurations and data flows are possible depending on the system design.”  That leads me to believe that today’s Apple-only copper-based implementation isn’t going to be the only version of Thunderbolt we see released and it might be the only connector type we see either.  Might we see a version of Thunderbolt that combines PCIe and HDMI?  Or PCIe, DisplayPort and

If that is the case, it could cause a lot of confusion in the market which would be a let down considering how impressive the tech is in and of itself.

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The Thunderbolt controller itself is responsible for both the merging and separation of the PCIe and DisplayPort data to be distributed to the various devices as needed.  That would mean if you have a Thunderbolt cable going from your notebook to a NAS, and then a cable from the NAS to an external mini-DisplayPort display, the display data is going to be decompressed, re-compressed and the passed through NAS and on to the display where it is actually need.  And all of this happens with incredibly fast access times, according to Intel.

Intel also discussed a bit more about the daisy-chain capability including a limit of 7 total devices.  That should be more than enough for just about any consumer / professional uses cases but the 8ns accuracy time across these devices is what gives the Thunderbolt technology its incredibly low latency access.  This is why both Intel and Apple are comfortable discussing Thunderbolt as the interface for huge storage arrays and possibly even bootable disk drives.

Update 3
According to this post over at engadget, it looks the amount of power associated with the Thunderbolt connection is about 10 watts – just higher than the 8 watts provided by Firewire 800 and the 5 watts provided by the higher powered USB 3.0 connection.  This is ONLY possible due to the adoption of copper cabling and wouldn’t have happened on the original fiber optic version of Light Peak.

Update 4
Intel is working on an optical cable with the “optics on the cable, not the platform” in order to facilitate longer run lengths of cable, up to 10 meters.  The electrical connection on the device / computer would be unchanged.  That sounds interesting, but that cable also sounds very expensive.  Also, there won’t be power on those types of cables either.

Update 5
Intel says that they “expect this to be a complimentary technology to USB 3.0” and that the two will coexist on platforms.  In areas where they overlap, like in external storage devices, Thunderbolt and USB 3.0 will offer different “price / performance” options for consumers. 

Update 6
A developer kit will include an add-in card with Thunderbolt support but isn’t really aimed at consumers to integrate into their PC. 


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