Powering the iPad
The iPad is powered by a supposedly custom system-on-a-chip (SoC) called the Apple A4
. The only other detail about the chip from Apple is that it's clocked at 1GHz. This makes it comfortably faster than the CPUs inside the iPhone 3G (412MHz) and 3GS (600MHz), and while Apple has branded it as its own chip, it uses a lot of licensed technology. The CPU is a single-core ARM architecture Cortex A8, and the GPU a PowerVR SGX 535 - very similar to the chips inside the iPhone 3GS.
The iPad has the same amount of RAM - 256MB - as the iPhone 3GS, which is double what the iPhone 3G had. The 3GS is noticeably quicker than the 3G when it comes to loading games and moving between tabs in the browser, and the iPad is visibly faster still. It's so rapid that it's fun, for the first few moments, to just flick the pages of apps from side to side. Going back to the iPhone (especially the 3G), you really notice the speed difference, and it almost seems as if the iPad was the device that came first, and the phones are the spin-offs. Games load very quickly (you can see how quick for yourself in the video) and run smoothly. There's no fan, so there's no noise, and no disk, so there's no vibration - it's a far cry from the average laptop or the Xbox 360 and PS3.
The excellent teardown by iFixit
shows the A4 uses package-on-package construction. Inside the A4, three dies - CPU/GPU, two RAM dies - are actually layered on top of each other (iFixit has a beautiful cross section image, here
.). This helps reduce latency and power usage - as iFixit go on to state, in order to give the 10 hours of battery life Apple promises, the A4 is only using around 2.5W.
The iPad will be available in two varieties - one with 802.11n WiFi, and one with both WiFi and 3G, both with between 16 and 64GB of flash storage. Only WiFi iPads have actually launched, and we tested using a 16GB model.
The iPad's guts; image courtesy of iFixit
Clearly then, there iPad's silicon isn't taking up a lot of room, because it's very much an iPhone 3GS with a higher clock speed - instead, most of the space inside the iPad is taken up by the battery, and like the iPhone, externally, it's dominated by the screen. The iPad isn't a widescreen device, opting instead for a 4:3 display with a native resolution of 1,024 x 768 - so it can't display HD video either.
It's well worth looking past the numbers though because the screen is simply terrific, with beautiful, saturated colours boosted by incredible brightness. It's an IPS panel, so has excellent viewing angles, too. It's great for images, and game graphics look gorgeous - games with cartoon graphics such as Plants vs Zombies HD
and Fieldrunners for iPad
- look great, and really draw you in.
The iPad as a games machine
The success of Apple’s iPhone and iPod Touch range as a games platform, with some developers netting as much as $1 million USD a month
has obviously prompted a lot of people to immediately regard the iPad as a superior games platform. After all, as many people have pointed out, it is in many ways just a bigger iPod Touch.
Unfortunately, when it comes to the matter of usability things aren’t that simple. The iPad isn’t just bigger than the iPod and iPhone – it’s also heavier, not to mention slipperier than a greased eel in a bin-bag. 680g may not sound all that weighty (for the WiFi model we have here, which is the lightest option), but the iPad is simply too heavy to hold in the way that some games require. Consider that the PSP weighs 280g and the DSI 214g - respectively, well under half the weight, and about a third of the iPad's heft - and you get a sense of what we're talking about.
Sometimes it isn’t an issue – games like Plants vs. Zombies
and Tap Tap Radiation
are of a pace and style that they’re best played when you have the iPad laid in your lap or flat on a table, for example. Others though – notably dual-stick shooters or tilt-to-steer racing games, require you to hold the iPad up in order to play and at that point the weight can be an problem. Trying to play Real Racing HD
is especially difficult, while holding the iPad one-handed for more than a few minutes produces serious wrist strain. And we have strong wrists!
Making the weight even more of a flaw is the fact that Apple’s sleek design means there are absolutely no handholds. There’s simply nowhere to get a good amount of grip and, given how quickly the iPad’s backplate warms up (though it never gets truly hot), sweaty hands are unavoidable. After ten minutes of two-handed gaming it was all we could do to avoid dropping the iPad on the floor, so if you’re considering getting one then make sure you have change left over to buy a protective case with a handle or something on it.
The good news is that size-wise the iPad is pretty much bang-on. At 24 x 19 x 1.3cm it’s ideally suited to browsing the web and flicking through ebooks or comics, while squinting at your games is now a thing of the past. The thick bezel stops your hands ever blocking out the picture, while the screen supplies fidelity in abundance. Typing is a bit of a pain since the glass screen doesn’t feel nice to your fingertips and, held in landscape, it’s a serious stretch for thumbs to reach the middle of the screen – but luckily most iPad games don’t require much text input. Or, not the ones we looked at anyway…