Sony has long been the master of miniaturisation, helping Apple to make its first sub-notebook computer twenty years ago, the PowerBook 100 in 1991.

Now Apple is the industry leader in quality notebook design, but Sony is still using its expertise to try to out-shrink the doyen of consumer electronics.

The Sony VAIO Z Series is a thin and light ultraportable – thinner and lighter than the de-facto yardstick of notebook not-thereness, the Apple MacBook Air.

Let’s look at the numbers first, using the respective manufacturers’ specifications of 13in models.

Apple: 17mm maximum thickness, down to a 3mm minimum. Sony: a level 16.65mm.

Apple: 1.32kg weight. Sony: 1.18kg.

So Apple wins the first round, as it has reduced overall average thickness. And loses the second by 140g, quite probably because Sony has alighted upon expensive dark carbon-fibre for the Z Series chassis.

While the Sony Z Series takes Intel’s latest silicon, the second-generation of Core i5 and i7 processors, a similarly revised MacBook Air is reportedly waiting in the wings for Apple’s major OS revision next month.

The Sony VAIO Z is reliant on weaker Intel built-in graphics; but the Sony also has a major card up its sleeve. It can use an external graphics card, supplied as standard in a special outboard docking station.

Sony VAIO Z Series with PMD

The Power Media Dock (PMD) is a break-out box around the size of an external optical drive. Which is exactly what is is, in fact – a DVD±RW drive or, to order, a Blu-ray reader or even BD writer.

Sony Power Media Dock

This box also sports VGA and HDMI outputs, fueled by an AMD Radeon HD 6650M mobile-spec graphics card, with its own gigabyte of DDR3 memory.

The PMD also adds gigabit ethernet and three USB ports, one of those USB 3.0.

Sony (very) quietly adopts Thunderbolt

To enable the connection between laptop and dock, Sony has employed the latest high-speed Thunderbolt I/O technology from Intel and Apple. And amusingly, seems to be refusing to acknowledge either company in the VAIO product’s marketing and its own press releases.

Instead, Sony merely refers to the Thunderbolt I/O tech that connects VAIO to PMD as ‘the architecture codenamed ‘Light Peak”’.

Which is factually correct, if slyly disingenuous. Or maybe there’s a legal spate around the use of the Thunderbolt trademark without the preferred Mini DisplayPort connector: Sony has elected instead to pipe all that blindingly quick I/O through a regular-looking USB Type A port.

One thing we’re sure of, it’s not an optical conduit in use right now, despite Sony’s press release which states that the expansion module links with the VAIO Z via an optical cable.

We’re awaiting an update from Sony UK’s VAIO product manager on the absence of Thunderbolt labelling for the VAIO Z.

UPDATE: It has been confirmed by Sony's VAIO PR Manager Jessica Simpson that it is using an optical version of the I/O interface between VAIO Z Series and Power Media Dock:

'The Power Media Dock links to the VAIO Z via a high speed optical cable. This proprietary data connection was created in collaboration with Intel and is based on Light Peak. Originally, the codename Light Peak was designed to be used with an optical cable (hence the branding "light" in "Light Peak"). They then added conventional copper cable compatibility in the version of the technology Apple uses, which is branded Thunderbolt.'

Other touches

Other Apple touches can be found in the buttonless trackpad, that can be used to click in the corners for left/right input; and the VAIO’s optional backlit keyboard, now ironically stripped from the MacBook Air but still found on the Pro-labelled MacBooks.

Sony claims seven hours’ battery life for the VAIO Z, which can be doubled through the simple addition of a strap-on ‘sheet battery’ that covers the entire base.

Storage is courtesy of SSDs, either 128GB or 256GB à la Air, with an option up to ‘gen3’ 512GB for an additional £1170...

Memory is 4GB as standard, or 8GB to order. It’s not clear if the RAM is user-upgradeable, or if it must be configured with the required memory when purchased.

The display is refreshingly anti-glare, 1600 x 900 pixels as standard, or 1920 x 1080 to order. For a 13in panel, the latter would equate to a very finely resolved display, albeit with tiny screen fonts and icons until you change the scaling.

Processor options are Intel Core i5-2410M running at 2.3GHz, Core i5-2540M at 2.6GHz or Core i7-2620M at 2.7GHz. We’re looking forward to testing the VAIO Z, and will be checking its thermal management when using such a powerful chip in a small, composite-bodied notebook.

If you have to ask...

Prices start at £1434 for an absolute bare-bones 2.3GHz Sony VAIO Z with no PMD box, nor mobile broadband or backlit keyboard.

Currently the only complete package listed by Sony UK costs £2699. This includes Windows 7 Professional, Core i7 processor, DVD-based PMD, 8GB RAM and 256GB SSD.

At those prices, Sony must be expecting these business-skewed portables to be bought as tax-deductible computers for company directors, rather than ultraportable computing for the masses.

Sony UK expects the Sony VAIO Z Series to arrive in this country in late July 2011.