I remember the early days of the USB-vs-FireWire wars like they were yesterday, although Wikipedia reminds me that they were more than a decade ago (sigh). USB 1.0 arrived in 1996 but didn't begin to see broad adoption until two years later with version 1.1. When FireWire 400 (aka IEEE 1394a) emerged on Apple systems in 1999, its backers scoffed at USB's comparatively diminutive 11 Mbps peak (and much lower practical) bandwidth.

Intel and its partners' response was swift; USB 2.0 came on the scene in 2000. Its 480 Mbps theoretical peak bandwidth, coupled with Intel's refusal to integrate FireWire support within its core logic chipsets, doomed FireWire to niche status in spite of the subsequent emergence of the 800 Mbps IEEE 1394b variant.

Yet as anyone who's used a USB 2.0 hard drive or flash drive knows, the external bus's read and write performance still leave a lot to be desired, especially for video and other large-file-size material. eSATA attempted to address the issue, but its storage-centric focus left OEMs unwilling to adopt it en masse, from both incremental-cost and incremental-connector perspectives. What the industry wanted was an equally versatile but speedier successor to USB 2.0...

...and now it's got two. Yep, another standards war - except not in the traditional sense, as these two are complementary. The USB 3.0 specification was released in late 2008, with first products available beginning one year later. Designed primarily as a replacement for USB 2.0, it delivers 4.8 Gbps transfer speeds, along with discrete transmit and receive data paths. And courtesy of Intel's Ivy Bridge integration, USB 3.0 will soon become pervasive in a diversity of PC platforms and form factors. But more than a year ago, Intel and partner (and customer) Apple productized a copper-based version of an Intel-proprietary interface called Thunderbolt, formerly known as Light Peak.

Each Thunderbolt port handles 40 Gbps of aggregate bandwidth, consisting of two pairs' worth of distinct 10 Gbps transmit and receive lanes. Thunderbolt isn't so much about enabling the connection of discrete storage devices (although it has been used for just that by many early peripherals), but new PC form factors instead. If you have to give up GigE, Firewire 800 and a gigantic screen to build a sleek Ultrabook, Thunderbolt will give you access to those things via an external display. Did I mention that Thunderbolt carries DisplayPort as well as PCIe? 

To date Thunderbolt has mostly only appeared on Macs, but the Apple exclusivity period is now over. This year we'll see the emergence of more affordable second-generation controller ICs, resulting in Thunderbolt showing up in a diversity of PC platforms and form factors.

Anand has done several in-depth Thunderbolt peripheral reviews so far. And today we've got two more products up for evaluation; Seagate's 2 TByte GoFlex Desk HDD coupled with the company's just-in-production Thunderbolt Adapter, and Western Digital's two-HDD Thunderbolt Duo. Let's have a look, shall we?

I finally made the transition to a notebook as my desktop last year, a move many had made years prior. Quad-core mobile Sandy Bridge and good SSDs made the move simple for me, but Thunderbolt eventually made it near perfect. With only two drive bays in my notebook (I ditched my optical drive so I could have another SSD, something Brian Klug did back in 2010), there wasn't any room for good, high-performance, mass storage. Thunderbolt solved this problem for me.

Co-developed by Apple and Intel, Thunderbolt is a tunnel that carries both PCIe and DisplayPort traffic to the tune of 20Gbps per channel (10Gbps up and down). In the past, whenever you wanted to add a PCIe device (LAN, audio, high-speed storage, etc...) you needed to physically install that device in your system either via an ExpressCard slot on a notebook or via a PCIe slot on your desktop. Thunderbolt acts as a decoupler for PCIe devices, allowing you to put controllers that would traditionally lie inside your system outside of it, or even inside another device like a display. That's where the DisplayPort support comes in.

Apple's Thunderbolt Display is the perfect example of what Thunderbolt can be used to do. Take a DisplayPort panel, integrate Gigabit Ethernet, Firewire 800, audio and USB controllers and you've got Apple's Thunderbolt Display. In theory, you could connect a system that had none of these things, and the functionality would be provided exclusively by the display. Decoupling hardware like this allows OEMs to build thinner and/or smaller form factor machines (think Ultrabooks/MacBook Air), while allowing for full functionality when connected to a display. By carrying DisplayPort over the same cable, you can have a single cable that both extends functionality and connects your small form factor machine to a larger monitor. Thunderbolt enables the modern day dock for notebooks.

For all of last year, Thunderbolt was an Apple exclusive. This year, starting with the launch of Ivy Bridge, Thunderbolt is coming to PCs. We'll see it on notebooks as well as some desktop motherboards. Today we have the very first desktop motherboard with Thunderbolt support: MSI's Z77A-GD80.

Read on for our full preview of the first Thunderbolt PC motherboard.

We've been covering Thunderbolt storage ever since the first Promise Pegasus hit our labs last summer. Since then we've noticed a common theme: Thunderbolt storage is very expensive. Prices haven't come down much at all, although LaCie has helped fill in the gaps left by Promise's $1000 and up Pegasus line. I honestly wouldn't expect prices on Thunderbolt storage to drop until the second half of the year when cheaper Thunderbolt controllers (Cactus Ridge) are available. Ivy Bridge is supposed to bring Thunderbolt to PCs, which should obviously broaden the install base and hopefully push vendors to come out with more affordable solutions.

Thunderbolt is extremely important, particularly to the notebook-as-a-desktop usage model. Although SSDs have given notebook users desktop-like internal storage, external storage has often been painfully slow. The move to USB 3.0 helped address this, but thus far Apple hasn't adopted USB 3.0 in its machines. I suspect Apple will deliver USB 3.0 when it moves to Ivy Bridge in the coming months, but until then your options are limited if you've got a Mac. The fastest USB 2.0 devices are only good for around 40MB/s and FireWire 800 can deliver about twice that. If you need high speed external storage on a modern (2011+) Mac, your best option is Thunderbolt.

Thunderbolt's peak performance is very good. In our review of the Promise Pegasus R6 we measured 8Gbps of sustained data transfers from a four disk SSD array while driving a 27-inch panel, all over a single Thunderbolt cable. When it comes to storage, there's significant headroom in the interface. I don't believe Thunderbolt is quite fast enough to interface with a good high-end GPU, but it looks like we'll have to wait until at least 2014 to see that change.

LaCie's first foray into the Thunderbolt storage space came with the Little Big Disk. A hefty aluminum enclosure with two 2.5" hard drives (or SSDs) in a software RAID-0, the Little Big Disk hit price points as low as $399. If you need capacity however, you were left with Promise as your only option. Until now.

Read on for our review of LaCie's 2big Thunderbolt series drive.