10 of 14Image
The OLPC XO (left) has the biggest screen, measuring 7.5in. across the diagonal; the Intel Classmate and ASUS Eee both have 7in. TFT screens with native resolutions of 800 by 480 pixels.
The XO's screen is an innovative dual-mode TFT that can operate in greyscale/reflective mode to save power, or in LED-backlit colour/transmissive mode (shown here) for maximum image quality. In greyscale/reflective mode, the resolution is 1,200 by 900 pixels and power consumption is 0.1-0.2W; in colour/transmissive mode, resolution is approximately 800 by 600 pixels and power consumption 0.2-1W, according to OLPC.
The XO has a 0.3 megapixel digital camera to the right of the display; the Classmate has no camera, although there are plans to include one in the next version of the system; the entry-level 'Surf' version of the Eee (pictured here) has no camera, but slightly more expensive models have a 0.3 megapixel unit.
Here is the OLPC XO in e-book (greyscale) mode, with the screen rotated and folded flat, facing outwards. Flanking the screen are the speaker grilles, with the camera (right) and microphone (left) above them. Below the speakers are a quartet of game buttons on the right and a four-way directional pad on the left. Beneath these are the power button (right) and a screen rotation control (left). There are also LEDs for power and battery status on the right, and wireless acquisition and activity on the left.
The battery in our OLPC XO review sample was a 4-cell 3,100mAh LiFePO4 (lithium iron phosphate) unit, although 5-cell nickel metal hydride batteries (NiMH) are also used. Among the advantages of lithium iron phosphate are the absence of heavy metals and the ability to support more charge/discharge cycles than conventional Li-ion cells (OLPC quotes 2,000 in this case). Battery life figures vary, but in our simple rundown tests we got around 3.5 hours with the screen backlight on (colour/transmissive mode) and 4.5 hours with the backlight off (greyscale/reflective mode).
The Intel Classmate's battery is not designed to be easily removed — you need to undo four screws to get the protective cover off and two more to release the battery itself. Having done this, you discover a bulky and relatively weighty 6-cell 4,000mAh Li-ion unit. Intel claims around four hours' usage for the Classmate on battery power: this seems optimistic in our experience, although we have yet to formally test this.
The Eee has the most compact battery pack, a 4-cell 4,400mAh Li-ion unit for which ASUS claims 2.8 hours' life, which seems reasonable in our (so far anecdotal) experience.