Why I won’t buy the new iPad

The new iPad is out, and we’re all marvelling at it here in the office. It’s a great machine, and an object of primal technological lust… but I think I’m going to stick with my iPad 2.

This isn’t advice I’d necessarily give to anyone else, though. To most normal people (ie. those who don’t spend all day reading about every little technological hop that occurs), my reasons for waiting probably won’t register with the same importance. If you told me that the Retina display was enough for you to upgrade, I wouldn’t disagree at all.

But I’m through the looking glass. I see the compromises that have come about in the new iPad – the slight extra thickness, the noticeable extra weight, the fact that it runs hotter than the iPad 2 – and I know that technology is on the way that could solve these problems, and that it should all be mainstream by the end of 2012. Again, I wouldn’t tell other people they should wait for these reasons, because none of it is certain, but I’m confident enough to commit myself to holding off.

The problem lies in the fact that the A5X, and the new iPad by extension, seems like a half-way house to me. It’s plenty powerful, no doubt, but my issue isn’t with its speed – it’s the way it’s made. The A5X is fabricated using the tail end of the current generation of chip-manufacturing technology, but the next generation is in the process of arriving.

When the first iPad arrived with the A4 chip powering it, it used ARM’s Cortex-A8 processor technology as its basis. When the iPad 2 arrived, the A5 came with it, upgrading to ARM’s Cortex-A9 technology. Improvements from the Cortex-A8 to the Cortex-A9 meant that even if the chip in the iPad 2 was still single-core, like its predecessor, it would have been around 30% faster, despite them both running at a speed of 1GHz. The fact that the A5 was dual-core meant that the improvement was much higher than that in the end. (It was actually necessary to upgrade to Cortex-A9 to become dual-core at all – it wasn’t supported by the Cortex-A8.)

I bring up this confusing technological history because ARM is in the middle of rolling out its next generation of processor tech: the Cortex-A15. One of the companies that's comitted to producing Cortex-A15-based chips is Samsung, which manufactures Apple's chips. In like-for-like tests, a Cortex-A15 chip is said to outperform a Cortex-A9 chip by as much as 40%, so if a hypothetical Apple A6 chip used this technology in a quad-core processor, the performance would be phenomenal.

But speed isn’t the most important advantage of the Cortex-A15 technology. As I said, the A5X is pretty fast as is, but to accommodate it and the Retina display screen in the new iPad, the battery capacity had to go up by around 70%. This meant an increase in size and weight, and the sheer power of the new graphics chip is almost certainly why the new iPad gets noticeably, and perhaps even uncomfortably, warmer than the older one.

Part of the reason for this is that the A5X is manufactured at 45nm, the same as the A4 was. This has meant that as more technology has been added to the chip, it’s ballooned in size – the A5X is over three times larger than the A4. But Cortex-A15 will be made with a smaller manufacturing process – probably 28nm. Chips created like this aren’t that common yet, but Nvidia’s latest graphics cards use it, heralding its arrival to the mass market. In a year, it’s likely to be a perfectly reasonable option for an Apple A6 chip.

The advantage of manufacturing at 28nm is that the chip itself can be smaller, but also more power efficient. Having a smaller chip can potentially free up space inside an iPad that could be used for the battery, but the battery capacity could also be reduced. The end result is that the next iPad could go back to the size and weight of the iPad 2, and yet be far more powerful than the new iPad.

And if the whole chip is being created at 28nm instead of 45nm, that would include the graphics chip – the primary culprit for the new iPad getting hotter than its predecessors. Going to a smaller manufacturing process would mean having the same graphics power, but without the toastiness.

Looking at the broader technological roadmap, I think the next iPad will have all of the advantages of the third-generation iPad, but will remove the compromises Apple had to make to get there from the iPad 2. That’s the iPad update I really want, so that’s the one I’ll wait for.

Disclaimer: I reserve the right to buckle and buy one at any time. That screen is really nice.