Thunderbolt is the Intel-designed high-speed interface that Apple adopted in 2011. Thunderbolt 1 had two 10-Gb-per-second channels, one for video and one for PCIe 2. Thunderbolt 2, shipping on the new Mac Pro and the latest MacBook Pros, has a single 20 Gb per second channel that dynamically shifts bandwidth on demand.
For most applications, I doubt most people will see a difference between Thunderbolt 1 and 2. An 8 SSD Thunderbolt array? Then yes you will.
Intel designed Thunderbolt to scale to 100Gb/sec, so expect to see continuing Thunderbolt performance boosts. Skeptical about Thunderbolt's future? Don't be.
There were twice as many Thunderbolt peripherals at NAB this year than last; license prices have dropped and support improved; and now Windows machines, such as HP's droolworthy Z-series workstations, are supporting it as well.
My test system is a fully optioned 2012 MacBook Air: 2GHz i7 dual-core CPU; 500GB SSD; 8GB RAM; 2 USB 3.0 ports; and a Thunderbolt port. I already have a dock in an Apple 27-inch Thunderbolt display, but its USB2 ports limit its utility.
I have more than 10 storage devices, HDDs, SSDs, FireWire disks and eSATA and Thunderbolt arrays, over 20TB in all. I wanted more connectivity for my three-pound mainframe.
I've had mixed success with USB 3.0 hubs — four ports work fine; seven ports not so much — and while USB 3.0 to eSATA adapters worked well, they ate up hub ports. The Thunderbolt display has a FireWire 800 port which works with a FireWire hub.
Not much difference in the way the docks are packaged. Both have the clean, compact unboxing experience that Apple pioneered.
The Apple-friendly theme continues with their looks: both are silver aluminum that match Macbook cases. The Akitio dock is about the thickness of a DVD case, but about an inch and a quarter smaller on each side.
The Cal digit dock is thicker, longer, and narrower, which means it would take up less desk space. Both docks have dual Thunderbolt ports for daisy-chaining.
Both docks plugged in easily and daisy-chained out to my two Thunderbolt arrays and HD DisplayPort monitor. Whatever I plugged in was quickly recognized and available — with one exception.
But there's a big difference in features. Let's look at each in turn.
Akitio Thunder Dock
This dock nails storage connectivity. It has two Thunderbolt ports, two eSATA host ports with port multiplier support (claimed), two USB 3.0 SuperSpeed host ports, and one FireWire 800 host port with bus-power.
The USB 3.0 ports can also charge iPads and iPhones, and Akitio claims they can also power a Superdrive (Apple's DVD burner). But when I plugged in the Superdrive it didn't work and an error message popped up, saying "USB Device Needs Power." Oops! (Update: a firmware update fixed it and it works fine now.)
I attached the eSATA ports to 2 WD eSATA external RAID0 arrays and ran the Blackmagic Design Disk Speed Test. The Akitio eSATA ran 13MB/s faster (113MB/s) than a $25 Bytecc USB 3.0 to eSATA adapter on writes and 9MB/s faster on reads (123MB/s).
I also checked USB 3.0 performance, attaching a SATA SSD. The Akitio achieved 153MB/s on writes and 205MB/s on reads, while the Cal Digit came in at 137MB/s on writes and 197MB/s on reads.
None of these performance differences are large enough to be deal breakers, but the Akitio consistently clocked the best times.
The Thunder Dock also came with a Thunderbolt cable while the Cal digit did not. That's worth $30.
CalDigit Thunderbolt Station
The Thunderbolt Station is more general purpose. It offers three USB 3.0 ports — one on the front — Gigabit Ethernet, HDMI, audio in and out, and dual Thunderbolt ports for daisy chaining. No eSATA, but one more USB 3.0 port.
I was pleased to see the HDMI port because I hoped I'd be able to add a third monitor. Plugged one in and — tada! — nothing.
Turns out that two monitors on Thunderbolt is a hard limit. As soon as I detached my 2nd monitor, the HDMI port worked fine. The Superdrive worked on the CalDigit, after installing new firmware. It ripped and burned as if it were locally attached.
I've already noted the modest difference in USB 3.0 performance, but there's extra convenience in a front — and third — USB port.
The Storage Bits take
You won't go wrong with either dock. The difference is what you need. Several docks have a port configuration similar to the CalDigit — and I don't understand who it is aimed at.
If you don't have a Thunderbolt display and want two displays, the HDMI port is useful — but you can also plug in an HDMI or DVI adapter to the second Thunderbolt port. If audio and GigE are important to you — you need more than the MacBook Air's single audio port and a hardwired network — then the CalDigit will make sense.
Thunderbolt Ethernet, FireWire and DVI/HDMI adapters are cheap. High quality USB audio interfaces with pro connectors are what most pros will want.
If you are migrating from a last-gen Mac Pro and have eSATA and FireWire drives — as I am — the Akitio Thunder Dock is a great choice. The ports are fast and the setup couldn't be simpler.
For me, the Akitio Thunder Dock gets the nod because it does more of what I need. I have heavy storage requirements and the ease and performance of my legacy storage turns a little MacBook Air into an I/O monster.
And when I need to go on the road, a couple of pulled cables later it is the svelte little notebook I need.
Comments welcome, of course.