Thunderbolt – still in the fast lane?


Thunderbolt offers high speed but at the cost of very few connection points.

In theory, the Thunderbolt connection that’s been fitted to all new Macs since 2011 should offer tremendous connection speeds and be a fitting replacement to the Firewire connectors that Apple has used for the last 15 years or so. The standard was developed by Apple working in conjunction with Intel, and plugs directly into the PCIe bus. It offers 10Gbps in both directions, with each cable having the same connector at both ends. This is twice as fast as the 5Gbps that USB 3.0 can manage, but USB 3.0 is itself faster than Firewire 800.

To confuse matters there’s now Thunderbolt 2, in which both channels can be combined to form a single high-speed 20Gbps highway. It uses the same connector so it’s backwards compatible with Thunderbolt 1. However, take up of this is limited to some Macs, mainly the newer Macbook Pros. There are no peripherals or connecting cables to support it so for now any Thunderbolt device is only using the first version. 

However, looking at some of the benchmark testing that others have done it seems fairly clear that hard drives with a 7200 rpm speed will cause a bottleneck and you’ll only really get the benefit of the promised 10Gbps from a solid state drive. When it comes to a standard hard drive, USB 3.0 seems to be the best bet, being nearly as fast as Thunderbolt but with a lot more options. For starters, USB 3.0 is backwards compatible with the earlier versions.

Thunderbolt uses a similar connector to mini display port and can be used to connect either a monitor or a storage drive, but this dual capability is a huge problem for anyone with a Macbook Air, as these laptops only have a single port. The Macbook Pros on the other hand have both a second Thunderbolt and a HDMI port.

In theory you could daisy chain devices together – the standard allows for up to six devices to be plugged together. But that’s not so easy as most devices only have a single Thunderbolt port, which you’ll need to connect them to the Mac, rendering them as ‘end of chain’ devices. Some of the more expensive hard drives have two Thunderbolt ports but none have them have any other connectors such as USB.

However, there is not very much support for Thunderbolt, indicating that very few manufacturers think that this is going to be the next big connectivity standard. All new Apple Macs come with at least one Thunderbolt connection, but so far none of the PC manufacturers have adopted it, which has limited the number of third-party peripheral devices that are available. In addition, most vendors feel that Thunderbolt will eventually be superseded by a faster USB, which is already happening now that the USB 3.1 standard has been agreed, which promises to match Thunderbolt’s 10Gbps.

A further problem is that there are no true Thunderbolt hubs, if you assume that a hub should offer multiple ports, a not unreasonable assumption given that most USB or Firewire hubs offer four, six or more ports. In contrast, Thunderbolt hubs offer just two ports, one of which you’ll need to connect to your Mac, plus a selection of other ports, mainly USB 3.0. Bearing in mind that a Thunderbolt hub costs around £200 and a USB 3.0 hub weighs in at £50, it’s hardly surprising that there aren’t that many options.

I’ve counted three Thunderbolt hubs so far – from Elgato, Belkin and LaCie, plus a couple of others that appear to be clones of the Elgato hub. These all have just two Thunderbolt ports. The LaCie, which costs £150, also adds two eSata ports, which is handy if you have legacy drives. The other two have three USB 3 ports with the difference being that the Elgato also has a HDMI while the Belkin has a Firewire. Both of these cost £180, though you’ll also need to buy a Thunderbolt cable for the Belkin, which costs another £30. Then again, if you need a Firewire adaptor for the others, you’ll have to fork out another £30.

If you have an older Firewire device, and a spare Thunderbolt port then you can buy an adaptor, at around £30. But if you don’t have a spare port, then your choice is to buy a hub, or abandon the older drive in favour of a new USB 3.0 drive which will probably work out cheaper and be faster. There are no adaptors from Firewire to USB because the data streams produced by the two are not compatible. 

For now Thunderbolt cables use copper wires but the ultimate goal is to use optical connectors, which will allow for much longer cables and much faster connections, but be considerably more expensive, which is going to seriously compromise its popularity.

In many ways the Thunderbolt story seems a bit like Firewire all over again – a connection standard that is potentially faster than the alternatives but ultimately crippled by the lack of support from other computer manufacturers.

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