Archive for 2010

This blog originally posted on the Low Power Engineering Community 12/2/10.  http://chipdesignmag.com/lpd/absolute-power

This month, a little diversion from our recent deep dive into smart phones – I recently received in the mail my new MacBook Air!  First of all, kudos to the order fulfillment process.  I ordered my new baby on Friday.  It shipped from Shanghai on Saturday, and arrived at my door on Monday.  No special or delivery charges needed.  I had to order online in order to max out the memory, both RAM  (4GB) and SSD (128GB), as well as the processor (1.6GHz).  And it was worth the wait – this little (11.6’) machine runs really well considering its processor is somewhat dated, and it LOOKS GREAT!  At 2.2 pounds (most of which is batteries) and sporting a 16:9 screen, it’s a natural for video, surfing the web, or any other activities you’d normally do on your laptop.  Microsoft Office (2008) runs nicely, as does Adobe CS5, and VMWARE Fusion 3.  I even spent quite a bit of time running StarCraft II over Thanksgiving (as a gaming benchmark only, of course), and it did a reasonable job as long as the graphics settings were medium to low.

So it’s a wrap, right?  Not so fast…!  We all know from our recent investigations that we’ve gotten beyond just the specs on computers these days – GHz and GB are no longer the most meaningful metrics.  And while running real world applications can tell us something about the utility of computing devices, for portable electronics, it’s all about battery life, or power efficiency.  So I ran the Air through my recent power testing setup – determine the power efficiency of the machine for playing back our reference movie, “Star Trek”!

The current champion for personal movie watching has to be the iPad – it’s a great combination of function and form, with a beautiful display and fantastic battery life.  Watching “Star Trek” on these two machines was a great experience – both are very compelling as portable video players.  The Air has the definite advantage in screen size – it’s 16:9 aspect ratio was a better fit for the movie, resulting in a significantly larger picture even though the displays physically aren’t that much different in size (11.6” vs. 9.7”).  Both displays were nice and bright, but the iPad definitely wins for picture crispness and clarity.  The Air’s display is nice, but just did not seem to have the extra depth and contrast of the iPad display.

In terms of power efficiency, the Air carries a lot of baggage (for just watching a movie) – MacOS and the laptop platform is much more complicated than iOS, so we’d expect to see that overhead in the numbers.  And we sure do!  The iPad dissipated 6.2 Wh of energy to view Star Trek on maximum brightness and sound.  On the MacBook Air, the same setup used over 21 Wh of energy, nearly 3.5x!  Removing the display from the equation doesn’t help – with brightness and sound at minimum, the iPad uses 3.2 Wh of energy, compared to the Air’s 14.0 Wh.  That’s a 4.5x difference in energy efficiency.

So where does the new MacBook Air fit in today’s lineup of portable computing devices, and does it threaten the exploding market for the iPad and other tablets?  In my mind, it carves out a nice niche in the “ultraportable laptop” category, sitting between tablets, netbooks, and more traditional laptops.  With good performance, reasonable battery life, and style to spare, this category may well indicate the future of our laptops, absorbing the netbook category, as well as low-end traditional laptops.  But watch out for the growth of tablets in coming years.  Today’s tablets are attacking mobile computing from the standpoint of smart phones as opposed to laptops, and that philosophy seems to bring ultra-high efficiency, novel features, and slick packaging.  The Microsoft Office app can’t be far behind.

This blog originally posted on the Low Power Engineering Community 11/4/10.  http://chipdesignmag.com/lpd/absolute-power

As we look at power usage and efficiency of mobile devices, it seems only fair to expand our view beyond my personal stable of iOS devices.  This month, I’ve picked up a new Motorola DROID X phone, one of a spate of recently introduced smartphones looking to take a bite out of Apple’s iPhone business. 

And it’s an impressive piece of hardware, with similar specs to an iPhone 4.  A bright 4.3” display with 848×480 resolution is bigger, but lower resolution compared to the 3.5” 960×640 “retina display” on the iPhone 4.  The processors both run at 1 GHz, so both phones are quite capable, responding quickly to the multitouch interface, switching between applications and tasks with no problems.  I like the removable (and therefore upgradable) micro SD card on the DROID X, but mine was initially unrecognized in the device – I had to take out the battery and reseat the card for it to show up, and even now it’s a little flaky.  The quick hardware comparison round goes to Apple iPhone 4 – mostly for fit and finish – it’s just a plain sexy piece of technology.  The DROID X kind of reminded me of a Palm 3 (which I loved) when I first picked it up – a little “plasticky” compared to the evolved sensibility of the iPhone 4.

But perhaps the most important piece of hardware isn’t on the phone itself; it’s the cellular infrastructure that transforms these phones from novelty devices to modern day computing and communications devices.  My initial data on the “network” for each of these phones is a solid win on the DROID X side.  Verizon coverage is clearly superior to AT&T in the Palo Alto vicinity, including in my house (Palo Alto) and in my office (Mountain View).  It appears that with a good signal, the AT&T network may indeed be faster, but I’ll have some additional tests on that later.  Either way, from a user standpoint, consistent coverage definitely trumps network speed.  The network round easily goes to DROID X (Verizon).

On the software side, my new DROID X is running Android 2.2, the OS that has overtaken iOS on smartphones in only one year!  I’m new to Android, so not qualified yet to comment about daily usage, but my first impressions were that it seemed quite capable, on par with iOS.  However, I found a few subtle nuances in the user interface that were a little disconcerting – for example, scrolling the display had a slight delay, making it feel more like a simulation than the instant response on my iPhone, which really feels like you’re moving a piece of paper around.  And for the 2.2 rev of the OS, I found Android to be fairly unstable.  In addition to several apps crashing, my droid hung up quite a few times in the first couple of weeks, requiring reboot, and even got so far off into the weeds once that I had to take out the battery to reset it (can’t even DO that on my iPhone!).  More for stability than for features, iOS wins this round.

Applications software is difficult to rate; both platforms have many more apps available than I’ll ever try, but all of the requisite pieces seem to be there.  However, with regard to the overall user setup and interface, I have to say that I like the iTunes “all in one” idea much more than the “maybe-more-capable” but “definitely-more-hassle” setup on Android.  After seeing how much trouble it is to try to get everything set up on a new device, I’m much more forgiving (and appreciative) of some of iTunes’ restrictions.  Chalk another one up for Apple.

Killer apps on either device?  The one that sticks out on the DROID X is the nice integration in Android of voice activated mapping and directions.  Say “navigate to starbucks in palo alto” and it will do it!  I currently use a combination of google voice, google maps, and Navigon to do the same thing on my iPhone 4.  Nice job on this, Google.  On the Apple side, the killer app is simply that you get a piece of technology that lets you forget about technology;  ignoring the spotty coverage, it just works (someone should coin that phrase…)!  Next we’ll look at head-to-head power tests on the two platforms.

LATE-BREAKING FOOTNOTE: After my initial experience with the superior network coverage of the DROID X (Verizon), I went to the AT&T store and filed a complaint – and they gave me an “AT&T 3G MicroCell” device, which basically creates a mini cell site in your house!  I’ve been playing around with it, and I can now play the recent Star Trek movie on my iPhone 4 with just 2.8 Watt-hours of energy, streamed over 3G using the MicroCell (with a never-before-seen 5 bars of signal strength).  My previous tests consumed 3.4 Watt-hours in the same spot in my house (about 3 bars), and 5.3 Watt-hours in my poor-coverage (1 bar-ish) office.  And all of these measurements with brightness and volume at maximum.  As we postulated last time, signal reception may very well be the “smoking gun” of mysterious battery drain on these devices.  That’ll make running comparable power tests between the iPhone4 (AT&T) and DROID X (Verizon) a little trickier…

This blog originally posted on the Low Power Engineering Community 10/7/10.  http://chipdesignmag.com/lpd/absolute-power

Our cliffhanger from last time left us with the open question, “where does all of the energy in a 5.25Wh (watt-hour) iPhone 4 battery go during normal daily operation?”  Watching Star Trek as a test vehicle seemed amazingly efficient on iOS devices.  Our “Star Trek Inefficiency” metric (STI – energy used to watch Star Trek) showed STI=1.1Wh on an iPhone 4 in its most efficient configuration (airplane mode, display minimum, sound off), and STI=1.7Wh with the display and sound at maximum.  And further experiments demonstrate that energy used for sound via speaker, headphones, or Bluetooth are all small contributors to the energy equation.  So we’ve fingered the display.

But amazingly, that’s not the biggie!  As I’m sure you’re all screaming in your head by now (aren’t you?), we have conveniently ignored the contribution of the thing that makes today’s portable devices so compelling – COMMUNICATION!  Without the communications link, email is just a file of printouts, social networking is only possible within the range of your voice, and phone calls – well, when’s the last time you saw a phone booth?!  We are now completely dependent on wireless voice and data communications.  Remember when your parents used to complain to the phone company when there was some static on the phone lines?  Today, we pay nearly $100/month per person, and we live with service that cuts off 20% of all phone calls!

OK, rant finished – we’ve established that we can’t live WITHOUT it.  Now let’s see how much we’re paying to live WITH it – in today’s most important currency – ENERGY.

iPhone 4 STI=1.1Wh in its most efficient mode.  STI=1.7Wh with brightness and sound at maximum (it’s a great movie player).  Now, instead of playing the Star Trek movie on the device, let’s stream the movie via 3G!  The iPhone 4 STI with Star Trek streamed over 3G, STI=3.4Wh.  Wow!  Streamed (at a much lower resolution) via Netflix, Star Trek now requires twice as much energy as the full brightness case!  I ran this experiment at my house in Palo Alto, where my reception is pretty consistently between 3-4 bars.  Remember, battery capacity is 5.25Wh, so we’ve gone from 1/3 of the battery capacity to watch Star Trek locally in high resolution to 2/3 of the battery capacity to watch it streamed in low resolution.

And for my final trick, I wanted to find the perfect spot to rerun this test – 3G reception good enough to maintain the stream of data, but otherwise right on the edge.  A place of great 3G signal suffering.  Not a dead zone, but something like eternal reception purgatory.  No bars…one bar…two bars…one bar…  Eureka!  On my desk in my office!!!  The perfect spot (and I’m SURE one of only a few spots on earth) where you can be tempted, enraged, encouraged, and frustrated all while trying to read your email.  In this “mystery spot”, where good 3G reception and evil 3G reception wrestle to the end of time, the STI on my iPhone 4 came out to be 5.3Wh!!  Woah!  You’re probably thinking, “Hey, I thought he said the battery capacity on the iPhone 4 was only 5.25Wh?”  And you’d be correct – in this magical spot (where I sit everyday), I can drain a fully charged iPhone 4 battery in less than two hours, and not even see Spock do his little telepathic speech at the end!

The revised list of ways to improve your iPhone 4 battery life:

3. Forget everything else on the lists you read on the internet

2. Turn down the brightness on your display

1. Improve your reception

It turns out that “improving your reception” isn’t so easy to do – you could be promoted and move to the corner office, sell your house and choose your new one by “closely watching the little bars”, or for no money and little fuss, simply get a case for your phone!  Remember iPhone 4 “antenna-gate”, resulting in the Apple free case program?  It turns out that using a case for your phone not only avoids the “death grip” problem, but also moves your hand (which is mostly water) a little bit away from your phone, slightly improving antenna performance and reception in both cases.  The result is a one or two-bar improvement in signal reception, especially in areas of generally weak reception.  And we’ve already seen that one or two bars of reception can have a profound impact on battery life – in our case, a jump in the STI from 3.4Wh to 5.3Wh just based on those one or two little bars.  So, for the purposes of streaming Star Trek over 3G, that free case may just contain a supplemental 1.9Wh battery!  But don’t let Apple know, or the prices will be going up…

And yes, I got my case through the free case program, but I’m not using it.  Why not?  I just don’t like the way it looks. (Go figure!!!)

When we last left off, I was attempting to do a “product-level” power analysis of my iOS devices, with the goal of identifying the modules that consume the most energy during a viewing of the recent “Star Trek” movie.  To develop a minimum power baseline, I ran the devices (iPad, iPhone 4, iPhone 3GS, iPhone 3G) from full charge to shutdown, with brightness at minimum, sound off, and “airplane mode” on.  The results were impressive: the iPad’s Star Trek score was 7.75 (played the movie nearly eight times in a row), followed by iPhone 4 with 4.75, iPhone 3GS with 4.0, and iPhone 3G at 1.75.  Since the 3G was a couple of years old, I attributed the low Star Trek score to a drop in battery capacity over time, and removed it from further trials.

A few observations about the tests: the minimum brightness setting on the iPhones resulted in a very dim display, only reasonably viewable in a dark room.  The iPad minimum brightness setting was much better – all but the darkest scenes were viewable, but not spectacular.

As far as establishing baseline data, the outcome was very positive.  The iPad and iPhone 4 devices’ power indicators tracked remarkably linearly, just looking at battery power percentage indicator.  Except for some “stickiness” at 100%, probably either due to a slight over-voltage condition on a fully topped-off battery or a deliberate “reserve” behavior to make it look like the battery is “full” for a little longer, the Star Trek runs all came in within 1-2% of relative battery usage, all the way down through the 20% battery indicator warning.  The 3GS was a little less linear, so I opted to proceed with testing just on the two newest devices (with new batteries).  Based on this data, I short-circuited my data gathering methodology to a single run per configuration(repeated to verify) between 99% and 20% battery capacity on the iPad and iPhone 4 devices, rather than running tests from full charge to shut-down.  Thank goodness, because staying up all night watching Star Trek over and over gets old quickly…

Combining the Star Trek results with published battery capacity for each devices yields the “Star Trek Inefficiency” – that’s the amount of energy used to play the Star Trek movie on a device (higher is worse, like golf).  iPad: STI=3.2Wh, iPhone 4: STI=1.1Wh, iPhone 3GS: STI=1.0Wh.  Since the iPad and iPhone 4 have similar hardware configurations, the difference in energy is due mainly to the display - 2.1Wh is a pretty reasonable extra cost for viewing on the larger, brighter screen.  But note the relative cost of the display on the iPad – based on this data, at least 2/3 of the power used by the iPad while watching a movie is just for the display!

Next, the most obvious big-power item – juice up the display.  I ran tests in the same configuration, except with the display brightness at maximum.  The first unavoidable conclusion – the new displays are gorgeous!  The iPad had a big, bright display, compelling from many angles, making it a great platform for sharing movies and videos.  The iPhone 4′s new display was equally impressive – incredible resolution and clarity.  But here’s where size matters – no matter how you slice it, watching movies on the phone-sized form factor is a compromise, and a single-person activity at best.  The iPhone 3GS display was unimpressive – small, and lacking in contrast and clarity.  In one year’s time, this phone has gone from state-of-the-art to also-ran.  Things are tough on the bleeding edge.

Here are the results for the “high-brightness” test.  iPad: STI=6.2Wh, iPhone 4: STI=1.7Wh

Now the costs of the display are getting clearer (pun intended).  On an iPhone 4 with minimum brightness it takes 1.1Wh of energy to view Star Trek.  With similar hardware and software on an iPad with a large display at max brightness, 6.2 Wh of energy are required, suggesting that 85%-90% of the battery power is going directly to providing that big, bright, beautiful picture.

And what about all the other power drains on the device?  I played Star Trek on the iPad in “max movie” mode, with brightness AND sound at maximum.  No change in energy consumption.  Tried it again with my favorite headphones – a pair of Shure E5C’s.  Same result.  Sound is free?  Hmmm…more experiments necessary.  I watched Star Trek using a pair of Altec Lansing BackBeat 903 stereo bluetooth headphones.  Surely that would have some impact.  It did, but only a small impact.  1% more energy used on the iPad battery meter, bumping the STI up to 6.4, which is something like an additional 200 mWh over the whole movie, but the 1% is also at the accuracy of my measurements, so almost inconclusive.  Finally, my big shot – stream the movie rather than playing it locally!  I viewed Star Trek on the iPad streamed over wifi using the latest Netflix app.  Amazingly, the STI was still at 6.4!  What gives?  These scores are still pretty reasonable, suggesting better battery performance than what I generally see in real life (I guess I no longer regard watching Star Trek as real life!).  Where is all that power (energy) going?

Next time, some answers to the mystery, some suggestions on improving the battery performance on your iOS device, and some conclusions to our “product level” power analysis experiment.

I like mazes and puzzles.  And I like algorithms.  When I was young, I discovered that most mazes could be solved almost trivially by applying a simple divide-and-conquer approach: solve the problem from both ends.  I would start with a pencil in each hand, one at the beginning and one at the end of the maze.  Then all you really have to do is draw until the lines cross.  I didn’t realize it at the time, but the effect was to halve the depth of the search tree – two trees of depth N/2 generally works out better (way better!) than one tree of depth N, especially when you can apply some high-level guidance and heuristics, like a kid staring at a maze.

As we all have been thinking in recent years about the problems of power dissipation in devices, chips, SoC’s and systems, I thought it would be interesting to start to look at the problem at the highest level – that of the end product.  Beyond the system level, above the system software, and even above the application software, the ultimate challenge is to be able to analyze and optimize power at the product level.

You must be thinking, “Is he nuts?  We’re not even close to the point of completely understanding power behavior through the system level, let alone interactions and dependencies through the software stack.”  So what is this all about?  Simple.  I’m just suggesting to tackle the problem from the finish of the maze.  I’d like to know, starting on the finished product end, how much power is consumed in particular modules, for particular operations. 

To get started, I’ve lined up my trusty set of iOS devices: iPad wifi, iPhone 4, iPhone 3GS, and iPhone 3G.  I’ve nixed my iPod Touch because it doesn’t have enough free memory to load our test vehicle.  As a measuring stick, I’m using a digital copy of the movie Star Trek (hey, if you’re gonna watch a movie 100 times or so, it might as well be a good one).  To develop a baseline, I fully charged all of the devices, and then played Star Trek as many times as I could until each device shut down.  This was done in a “max battery” configuration: airplane mode, with wifi, bluetooth, and location services all off, brightness and sound at minimum.  I suppose you could use this setup as a movie player in a very dark airplane (if you knew how to read lips)!  It might not be realistic, but the experiment yielded very interesting results.  All of the devices performed much better than I expected.  The iPad played Star Trek (2 hours, 6 minutes, 46 seconds) 7 and ¾ times before draining its battery completely!  That’s over 16 hours of video playback!  Similarly, the iPhone 4 had a Star Trek score of 4.75, and the 3GS around 4.1.  Both were over 8 hours of video playback.  The iPhone 3G only lasted through 1.75 Star Treks, but it’s also the oldest device (over 2 years), so its battery capacity is probably down by at least 30-40% (no I don’t know how many “charge cycles” it’s been through).

After all of those millions of recall petitions, email campaigns, blogs, and general nasty comments about battery life, is it possible that we’ve all got an 8+ hour portable movie player in our pockets and purses?  Yep.  So why is it that my original iPhone couldn’t last through the morning at work, with subsequent versions only marginally better?  What’s using all that juice?  And wouldn’t it be cool if we could tell during the design phase of the phone that this would be a problem?

We’ll answer these questions starting next time.  Let’s start walking back from the end of the maze.

By Cary Chin

07 July 2010

“Leakage Power – the big picture”

We’ve all been working on power engineering for a while now, and leakage power is always one of those generally-confusing topics.  Sub-threshold leakage, field-effect transistors, MOSFET weak-inversion regions – these are all things that cause even experienced engineers’ and computer scientists’ eyes to glaze over.  It all falls under the general topic of static power, or “standby power” in more macro terms.

We all know of standby power as the power your television and computer (or other appliances) consume when they are in standby mode, waiting to be turned on by you.  Generally, it’s energy that is consumed that doesn’t serve any useful purpose, other than standing by for input.  To stretch the definition, it might even include all of those blinking “12:00” clocks on our VCR’s over the years – thank goodness we finally got rid of those!

The recommended practice for wasting as little energy as possible on your home electronics is to unplug them, or switch off the power strip when they are not in use.  But did you know that it makes a difference which end you unplug?  Even with the latest EPA Energy Star guidelines, power adapters are limited to ½ watt under NO LOAD – that’s right, just the adapter plugged in without the appliance draws some energy.  I don’t know about you, but we must have at least 40-50 adapters plugged in 24/7 in our house – those things are going to add up.

In low power engineering terms, this is exactly the idea of “power gating” or “power shutdown” – unplug those transistors when they’re not needed, and you lower the leakage power to zero.  Of course, unplugging your computer and plugging it back in every time you need it is a little inconvenient, so in our real life example we must make the same tradeoffs that we make when engineering our advanced low power chips – how long will it be off versus how long it takes to start back up.

And finally, I heard this morning that with the current heat wave on the east coast, energy demand was soaring, and the power grid was strained, but holding its own.  I immediately thought of power rail analysis.  And when the news story added that some utility companies were lowering their output voltage to save energy, I could only think of three letters, “DVS”!  Maybe I’ve been at this for too long…

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.

This blog originally posted on the Low Power Engineering Community 5/13/10.  http://chipdesignmag.com/lpd/absolute-power

We all think of mobile electronics today as smart phones, laptops, cameras, video equipment, gaming machines, and a whole host of devices designed to untether us from the dreaded power cord. Yet we don’t usually associate our most mobile and, recently, most electronic device in the same category. Let’s take a look…

Back in the year 2000, when I was working on processor design at Sun Microsystems, Scott McNealy was fond of pointing out that the value of the electronics in the cars back then had caught up with and overtaken the value of the steel in those same cars. “You’re driving a computer to work, not a car,” he quipped. While today’s cars don’t look any more like computers than their brethren of 2000 on the outside, we’ve added GPS navigation, satellite radio, integrated MP3 storage, voice recognition, Internet connectivity, WiFi, Bluetooth, heads-up display technology, automatic lane tracking, automatic parallel parking, solar charging, and a host of other features in addition to the electronics actually used to build the car.

And there’s more to come. There’s no doubt in my mind that a “few” years from now, “mass transit” will mean electronic highways that can accommodate a much higher density of cars with many fewer traffic accidents and injuries. Put those same cars in manual control mode, and you’ll be able to zip along a country road with the wind in your hair, adjusting the exhaust noise to your pleasure, from “hot rod” to “silent” (they’ll just be recordings). The only downside is that you’ll also very likely be getting an automated speeding ticket in your e-mail.

We’re not there yet, but at some point in the future the power usage of electronics built into cars might even exceed the power needed to drive the wheels. Wouldn’t it be funny to ask the car salesman of the future, “I like the super-deluxe 3D heads-up display with sense-around technology, but how will it affect my mileage?”

Things are definitely getting interesting.

This blog originally posted on the Low Power Engineering Community 4/08/10.  http://chipdesignmag.com/lpd/absolute-power

My iPad arrived as promised last Saturday morning at 11:00am. Woohoo! And it’s been ON for probably 80 of the 100 hours between then and now. While my parents (now in their mid-80s) think I’m nuts, my kids are having a great time! Here are my top five initial impressions.

1. It’s a more personal experience. I haven’t thought much before about how restricting it is to use a mouse and keyboard to interact with everything on a computer. My iPhone changed that somewhat, but on a device that small you lose more than you think by having to scroll around all the time. This thing is great for browsing the Internet, reading news and books, even watching a movie or listening to music, all from your favorite armchair or (I can’t wait for summer) lounging by the pool.
2. It’s a more social experience. I brought my fresh-out-of-the-box iPad to a family gathering on Saturday and it was the center of attention. The optimal placement for one of these things is NOT on a desk or on a bookshelf, but on a coffee table or a dining room table, where people can see and interact from all sides – like the old PacMan table-top arcade game! Suddenly a laptop, with its lid blocking 180 degrees of the view, and keyboard accessible from only one direction, seems mighty restrictive. And it’s now clear why those meetings at work seem even more boring these last few years – staring at all of those grey laptop lids is pretty claustrophobic, even if the people behind them are actually paying attention.
3. Size matters. Yeah, the iPad might be just a giant iPod Touch, but what’s wrong with that? In fact, applications like reading books and magazines, watching videos and movies, and browsing the Internet were compromises in the smart-phone form factor. Plus, everyone I’ve talked to over the age of 40 has said, “Whoa, I can actually see the screen!”
4. Saved by the virtual keyboard. I don’t know what percentage of people these days are trained touch-typists, but I’m not. I can keep up with most people in typing English, and consider myself “above average to superior” when typing in a typical computer program. (Remember how fast you used to be able to type “begin” and “end”?) My biggest problem has been that I need to look at the keyboard while I’m typing. I never realized how much of a disadvantage this is. I’ve gotten used to typing things like this blog very quickly, and then looking up to see if it all came out right. Now, with a large virtual keyboard, suddenly I’m looking at the keyboard and the output at the same time!! Ha! Take that, Mavis Beacon!!! It’ll take some practice, but I’m thinking this is a great combination for people like me.
5. More to come. One of the ways you know you’re onto something important is when you keep getting new ideas for extension, expansion, and innovation. After playing around with the iPad for a few days, I’ve put together a prototype sheet music library/displayer using pdf files, thought about kids no longer carrying around 30-pound backpacks, mused about the ultimate Internet-connected-digital-photo-frame app, and can even imagine an iPad (maybe connected to a TV or projector) along with four iPhones – as the ultimate gaming system! Watch out, Wii. Now’s a good time to start that iPod Touch wrist strap business…

On the downside: fingerprints. Ouch – this thing is a CSI field day! Along with those wrist straps, the “iScreenWipe” or “iGlove” or “iBottleOfHandSanitizer” would be a definite winner.

So how is all of this connected with our world of low-power engineering? What I haven’t complained about, or heard anyone else blog about since Saturday, is battery life. In fact, my iPad ran for more than 11 hours of movie watching, Internet surfing, multiplayer gaming, and app downloading on its first charge, and has been going strong ever since. Amazing. We’ll look at the numbers in a future blog.

The iPad has been a hit for everyone from ages 6 to 85 (I haven’t sampled outside that age range yet) – and I’ve already purchased a second one for the high end of that range. My parents saw our iPhone videos of our kids played on the iPad, and just had to have one. Grandkids’ videos and pictures – priceless!

This blog originally posted on the Low Power Engineering Community 3/11/10.  http://chipdesignmag.com/lpd/absolute-power

Driving in to work a few weeks ago in uncharacteristic fog, I noticed a streetlight was out. A little strange that there were no signs around, but I did the obligatory 4-way stop, and continued on my way. When I arrived in my office, my wife called, and said that the power was off in our neighborhood. Not a big deal, as it was only a little after eight in the morning, but I started poking around online at the office and through the magic of our modern communications infrastructure the picture began to emerge. First through Twitter, then blogs, then news stories: fog, plane crash, fire, transmission tower, you know the rest. Interestingly, my wife could have gotten all of this at home, as well, on her iPhone, but the networks were jammed with Palo Alto residents trying to get information.

I remember years ago when the power went out, the biggest concern was, “I hope the stuff in the freezer doesn’t thaw out.” Today, everyone’s first reaction is, “is the Internet still up?” We are addicted to getting our information in real-time, as it happens, from multiple sources – including live tweets and cell-phone-cam footage, as well as traditional media (who seem slow in comparison). And while that brings up some real questions about the future role of the media, our ability to communicate with each other and the world in real time is truly revolutionary. Mobile Internet devices are removing the last remaining tether preventing the information superhighway from taking flight: the power cord. Upcoming generations of devices will continue to improve functionality and power efficiency, and the sky’s the limit.

But all is not well in our low-power engineering community. The pilot of that small plane that crashed in the fog in Palo Alto three weeks ago was Doug Bourn, senior electrical engineer at Tesla Motors, who worked on the main power module of the Tesla Roadster. Prior to Tesla, Doug worked for many years at a small product design and development company called IDEO Product Development. And one of his close colleagues at IDEO was my wife. We are bummed.