Asus always saves something a bit special for CES, and this year was no different; the Transformer Book Chi is thinner and lighter than a MacBook Air , yet splits apart and becomes a standalone Windows tablet that arguably wipes the floor with Microsoft's Surface . It was originally revealed at Computex in the company's native Taiwan late last year, but as a prototype device with no release date. Now that Intel's energy-sipping Core M processors have arrived, the time finally came to make the Chi official.
We got the chance to try it out today at the Asus booth, in order to see if it's the hybrid that will replace your traditional laptop.
Whether you treat it as a tablet with a keyboard dock or as a detachable laptop, the Transformer Book Chi is an incredibly thin 16.5mm when combined with its Bluetooth keyboard. That's slimmer than a MacBook Air, and at 1.42kg it's not going to weigh you down when taking it on the move either. Detatch the pair with a firm tug and the tablet is ready for standalone use, weighing just 720g and measuring 7.6mm thick. It's a massive improvement over the Transformer Books of old, to the point that you could replace a few years-old Android or Apple tablet and barely notice the difference in your bag. It's so thin that there's no room for a full-size USB port on the side of the tablet; instead you get a micro HDMI video output, 3.5mm audio jack and mini USB3 type B port, for which you'll need an adaptor to use with regular devices.
There's little sign of flex or give in either the tablet or keyboard, despite being so thin, and the soft touch finish on the back of the tablet means it shouldn't slip out of your grip. Despite not having a traditional lock, the mechanism Asus has used held the tablet firmly in place on the keyboard dock even when we gave it a strong shake, so it shouldn't ever pop out unexpectedly.
The bezels around the 12.5in display aren't incredibly thin, but leave enough room to comfortably rest your fingers when gripping the tablet in either portrait or landscape modes. The screen itself is a stunner, with a 2,560x1,440 resolution that works out at 235 pixels per inch - high enough that you can't spot the individual pixels unless you press your nose to the screen. Both images and text looked pin-sharp, but the Windows Desktop was still perfectly legible at the higher resolution. Desktop mode on Windows 8.1 still isn't the easiest interface to use with your fingers, but it works flawlessly in Modern UI mode.
Thankfully the keyboard works perfectly when it's time to get some real work done. The QWERTY keys are all full-size, with a reasonable amount of travel considering how shallow the keyboard tray must be. You don't get backlit keys for working in the dark, but we would take comfortable, responsive and springy keys over inferior backlit ones any day. The all-in-one touchpad is a little small for our tastes, and we would have preferred separate touhpad buttons to avoid any accidental gesture inputs. At least the keyboard connects via Bluetooth, so you can continue to use it even if you haven't docked the tablet.
The only major criticism we have right now is the fact the keyboard doesn't have any kind of internal battery for extending tablet battery life when docked. Of course, this would probably add to the dock of the keyboard and spoil Asus' "thinner than Air" message, but an alternative keyboard/battery booster would be a welcome addition to the range.
Inside the tablet, Asus has used an ultra low voltage Intel Core M processor, which can push both its cores up to 2.9GHz when thermal limits allow, yet requires no active cooling. That means the Transformer Book Chi is completely silent, with no moving parts thanks to the 128GB SSD. Paired with 8GB of RAM, the model on display at the Asus booth felt satisyingly responsive, opening and switching between programs with no discernable lag or sluggishness. We'll have to wait until we get a final retail model into the labs to pass final judgment on performance, but it should easily be capable of basic office work, multimedia playback and web browsing. Asus expects the tablet to last up to eight hours on a single charge too, as the CPU is impressively frugal with its power consumption.
Despite our concerns with the keyboard's limited functionality, w e can't wait to get hold of the transformer Book Chi and give it a full review a little closer to launch. It looks stunning, feels well made and has the power to replace a traditional laptop, yet has all the flexibility of a tablet. We shouldn't have too long to wait, either; Asus expects it to go on sale in the coming months, with prices starting from around $799 (roughly £530 before you factor in tax and VAT).
