Silicon Power T11 120 GB review

If it’s fast storage you seek, there’s nowt faster than Thunderbolt-connected devices at the moment. At least, that’s the theory, given that Thunderbolt is demonstrably the fastest conduit on the market. It’s based on PCIe, the same high-speed pipes that connect much of the internal sub-systems of modern high-performance desktop and laptop computers.

Unfortunately Thunderbolt has a dirty secret. While it can signal at 10 Gb/s, even send user data at a significant fraction of that headline speed, if a storage device is to be bus-powered then the whole process only works at a small fraction of the headline speed.

See also: Storage reviews

In the case of the Silicon Power T11, we have a portable external drive packed in a box brandishing the usual fictional graphics that promote a 10 Gb/s speed – but it’s not until you read the manufacturer’s smaller print that you see the 340 MB/s. Translating bytes back to bits, that’s under 3 Gb/s, or less than a third of Thunderbolt’s advertised performance.

The problem – and by no means unique to Silicon Power – lies in the power budget. When Intel and Apple cooked up Thunderbolt, née Light Peak, they only allocated it with 10 W of bus power to pass on to unpowered devices like portable storage drives. Two or 3 W of that 10 W is used to just fuel the active cable with its chips hidden in each plug.

Then there’s the SATA to PCIe and Thunderbolt electronics, draining another few watts. It leaves around 5 W or less for the solid-state drive itself. And while many SSDs can idle at under a watt, transitory power demands can spike well above the strict limits that certified Thunderbolt devices can supply.

So economies are made in the power budget by only using a single PCIe lane, for example, which may explain why every bus-powered Thunderbolt drive to date significantly under-achieves the format’s potential.

Silicon Power T11 120 GB - Whither USB 3.0?

For context, a comparable portable flash drive with USB 3.0 (which will also typically boast a theoretical number, such as ‘SuperSpeed 5 Gb/s’, will also get nowhere near its advertised performance.

But provided that it’s enabled with USB attached SCSI protocol (UASP) it should reach speed of around 440 MB/s.

Silicon Power T11 120 GB - Build and Design

The Silicon Power T11 is not alone in underachieving somewhat, and while it’s being severely reined in by the current laws of silicon physics, it’s still pretty damned fast as a pocketable flash drive.

There’s only one capacity available, 120 GB, priced at £215. The unit was formatted in Microsoft FAT out of the box, which can be read and written to by a Mac, and it’s a simple matter to reformat into HFS+ in OS X’s Disk Utility application.

At just 74 x 15 x 62 mm, it’s significantly smaller than the obvious contender from Elgato, the chunky Thunderbolt SSD. It’s light too at 61 g, made from smart satin aluminium with Apple-inspired white plastic trim on each face of the extruded chassis.

We’re not entirely sure what’s inside but would guess it’s an mSATA SSD, whose controller should take care of the essential housekeeping as flash blocks become full, tired or worn out.

A cute little white Thunderbolt cable only 280 mm long is also included in the box, handy given the high price of these sophisticated cables.

Silicon Power T11 120 GB - Performance

Under test we did measure transfer rates a little higher than the specified 340 MB/s, hitting a maximum of 382 MB/s for large sequential reads above 20 MB data size.

In the small file range, single-threaded transfers were recorded at 20 MB/s random writes and 22 MB/s random reads, both excellent results at this level.

Averaged from 4 to 1024 kB, the drive recorded 168 and 143 MB/s for reads and writes respectively, again good figures which bode well for juggling everyday small files.


The Silicon Power T11 is very lightweight and compact storage drive with good performance. It falls significantly short of real Thunderbolt speeds, but this is true of all current bus-powered Thunderbolt drives. Construction quality and style are on-trend for Apple peripherals, and it will make a useful if expensive desktop accessory.

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