Posted by Cary Chin on June 22, 2010
This blog originally posted on the Low Power Engineering Community 6/10/10. http://chipdesignmag.com/lpd/absolute-power
If you’ve been reading this blog for a while you know that I’m kind of an Apple bigot – from the original Macintosh (remember that “1984” commercial?) through those clunky Mac clones, cool (and sometimes HOT!) laptops, Newtons, and now iPods, iPhones, and iPads, I’ve pretty much tried ’em all. So no surprise that I was carefully tuned into this week’s announcement of the iPhone 4. Here are my impressions from a low-power engineering standpoint.
Bigger battery: Hallelujah! From what I can tell looking at the somewhat-confusing details, battery capacity of the iPhone 4 is probably somewhere around 1,600 mAh, compared to around 1,200 mAh for the 3GS. Steve made a point to mention that new iPhone 4 case design allowed more room inside, specifically used to fit an enlarged battery. While this isn’t “low-power engineering” per se, increasing battery capacity is just as effective as decreasing energy consumption from the standpoint of usability, so this is a big plus.
New A4 chip: Another winner. Same chip as in the iPad, providing zippy performance with many advanced low power features. Check out my April blog for impressions on the iPad. With similar graphics resolution to an iPad, this phone (uh, I meant Mobile Internet Device) should have plenty of horsepower.
Higher-resolution display: On the downside (from the power standpoint), four times as many pixels will require more power to drive and update. It’s difficult to predict how much of an impact the new display will have, but based on the published info it appears that the new display hasn’t hurt battery life too much, at least from what we can see down at the bottom line. And the pictures looked great.
Multitasking: As much a feature of the phone as the OS, but the biggest question I have is regarding the need for multitasking on a phone. I understand the competitive pressures of Android and WebOS, and the “Hold on, I’ll find that presentation and e-mail it to you right now” commercial is pretty compelling, but on this kind of a device multitasking seems like too much power (literally) to put into the hands of hundreds of thousands of App developers out there from age 3 to 93, with an even wider variance in training and skill. The currency of a mobile device is power, and “using power wisely” is taking on a whole new meaning. It’s taken us this long to get up to 1,600 mAh, and I for one don’t want to use any of it on harvesting my virtual farm in the background or a runaway beer-drinking app!
Can’t wait to get my hands on one! See you all next month.