Single page Print

Boot time and battery life
Honeycomb had a tendency to boot rather slowly on the Transformer Prime, taking about twice the amount of time required to load the OS on the old Transformer. Fortunately, Ice Cream Sandwich boots much faster on the Prime.

The OS update cuts the Prime's cold boot time by more than half. The original Transformer is still faster, but the difference between the two tablets is minimal with ICS compared to what it was with Honeycomb. Both tablets continue to wake up from sleep almost instantaneously.

Last, but not least, we have battery life, a particular point of contention for the Transformer Prime. When we first tested the tablet, its battery life was wildly inconsistent in our web surfing test. That test loads up a version of the TR home page and refreshes it every 45 seconds. New ads are loaded each time, and browser plugins are set to "on demand" to prevent Flash from burning through the battery. That's still a heavy surfing load, but it's not the sort of thing that should produce a variance in battery life of several hours, behavior Asus confirmed in its labs.

With Ice Cream Sandwich on board, the Prime's battery life in our web-surfing test is now very consistent—and much improved. The tablet lasts for an extra hour with the new OS, and two more if you have the docking station attached. The original Transformer gains about an hour of web-browsing time thanks to Android 4.0, too. Its web-surfing battery life has been consistent since Honeycomb.

Our second battery life test repeats an hour-long 480p video clip encoded with H.264. We use the ad-supported DicePlayer app, which supports the Nvidia decoding mojo inside both tablets. This test is run in airplane mode, with Wi-Fi disabled.

Battery life hasn't improved for movie playback. The old Transformer offers identical run times when looping our H.264 video, while the Prime loses 1.5-2 hours. DicePlayer has been updated since our initial testing, so that may account for some of the difference on the Prime.

Because testing battery life is rather time-consuming, we were only able to run the Transformer Prime in balanced mode. The tablet is perfectly capable of browsing and playing our test video in power-saver mode, but that compromises the screen quality in ways we'd rather avoid.