The Apple iPad 2 Review
by Brian Klug, Anand Lal Shimpi & Vivek Gowri on March 19, 2011 8:01 PM ESTBattery Life
Testing battery life on a tablet is pretty grueling as these things are effectively smartphones with gigantic batteries. What would last for only a few hours on a smartphone can easily last over ten on a tablet. The iPad 2 is no exception.
As iFixit discovered, the iPad 2 features a nearly identical battery to the original iPad (25Wh vs. 24.8Wh). We already established that display brightness hasn't gone up so the only real impact on battery life will be because of the A5 SoC.
The iPad 2 WiFi's battery, courtesy iFixit
The ARM Cortex A9 tends to be more power efficient than its predecessor, the A8. With a shallower pipeline and the ability to execute instructions out of program order you get better performance per watt in most cases. As a result the A5 should complete bursts of instructions quicker than the A4 and get back to sleep sooner.
To put this to the test we put together a battery life test that combined our non-Flash smartphone web browsing test, checking for email every 15 minutes (via a Gmail account receiving ~100 emails per day) and constant local music playback while all of this is going on. The results are pretty much as expected:
Over WiFi the Motorola Xoom and iPad 1 deliver very similar results. The iPad 2 pulls ahead by around 8%, it's not a huge advantage but it's there. Over 3G there's a noticeable drop in battery life, putting both of the iPad 2s below 10 hours and kicking the Xoom down to under 9 hours. All of the numbers on this chart are respectable however and you can expect a good day's worth of use out of any of these tablets.
Note that while the iPad 2 did better than its predecessor if you were to run an app that pegged both CPU cores at 100% you'd see reduced battery life on the iPad 2 vs. the iPad 1. Granted you'd also see better performance on the iPad 2.
Video playback is obviously an important function of these new tablets so we put together a H.264 decode playback test as well. For this test we transcoded a copy of Quantum of Solace from a 1080p BD source down to a 720p H.264 using Handbrake's Normal encode profile with one modification. In order to enable smooth playback on the Motorola Xoom we had to disable b-frames in the encode. The results are below:
The iPad 2 consistently lasted longer than the original iPad in our video playback test. The Xoom however did noticeably worse. Unfortunately only a portion of the H.264 decode pipeline is accelerated by NVIDIA's Tegra 2 in this test. When playing back anything more strenuous, portions of the pipeline are handled by the CPU cores in software. If you were to enable b-frames the Xoom would not only stutter but its battery life would drop to around 6 hours.
On the iPad 2 its Cortex A9s are mostly powered down during this test, on the Xoom the A9s are helping with the heavy lifting for video decode and as a result we see lower battery life. Kal-El is expected to address this issue head on.
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Shadowmaster625 - Monday, March 21, 2011 - link
If that is true then why not focus on that? I still have yet to read anything on anandtech about remote desktop on a tablet. How powerful does a tablet need to be to stream 1-2 mbps compressed images of my desktop over wifi? I can skin my desktop to make it look more like a mobile OS. Touch commands can be fairly easily emulated and transposed into mouse commands. Audio doesnt require much bandwidth. Only video would present a problem, but even then it really doesnt take all that much hardware to play a video. Yet all I see are horrible implementations of remote desktop.marc1000 - Monday, March 21, 2011 - link
i remember reading here at AT that the Nokia N8 could be used to drive an HDMI display and hooked to an keyboard/mouse, to "simulate" a pc-like experience . and now the Ipad2 does the same thing, but 1 year later.IMHO all that apple does is beautifull, but they charge the price for the "beautifullness" of their products.
well, I just want a tablet/smartphone that works, so I will wait until these prices drop... until then I will live with my Htc HD (1st gen.. ugly!)
Watwatwat - Monday, March 21, 2011 - link
almost feels like i learned something:DJayman30 - Monday, March 21, 2011 - link
Maybe the iPad doesnt fit into a busy techbloggers "workflow" but as a consumer device it's an incredible gadget. My ipad 1 is used daily and has never sat on a shelf unused for more than a few hours. I reach for it first instead of my iPhone or clunky Gateway laptop for 90% of my daily computing needs. It has incredible performance, portability, battery life, and overall utility.I can buy & read books, download and play great games, movies and music quickly and easily. Great Email and web surfing are just icing on the cake! Works great for me!
FYI. iPad 1 costs $399 now.
cotak - Tuesday, March 22, 2011 - link
I am with the staff at anand. I use an iPhone 4. It's nice fo getting a little reading of news etc done. And I have looked at the iPad and I have consider getting one. And likely I will have one but not for myself. It'll be too limiting for me to use. For my fiancee though it's perfect since on a regular week she can go 5 6 days without powering up her computer.So is there s market for tablets? Maybe but I don't think it's big as various peope like to think it could be. And the fall out from that might be pretty big. Nvidia's betting on it, moto has only recently make it back into the black, and rim seems to have concentrated on the playbook over improving their last series of phone release. So maybe some of these players might not be be best stocks to hold for the medium term...
Anyhow tablets are useful for light use. But for people who use their devices/technology enought to justify spending regularly on technology, it might be too small and too slow. And really isn't the repeat buyer the important one I the market? My fiancee could get a iPad 1 and happly use it for the next 6 years without considering buying a new one. If people like that are the market, it's not going to be as big as some people in wall street seems to think.
vshin - Tuesday, March 22, 2011 - link
The one thing I'm surprised that isn't getting as much coverage is that small text is actually harder to read on the Ipad 2 than on the Ipad 1. Some folks chalk this up to being "spoiled" by the Iphone 4's retina display but it's actually because Ipad 2 implements heavy use of anti-aliasing, which can't be configured or turned off. I find my eyes tiring very easily as I browse the web or read on iBook in portrait mode.speedkills - Tuesday, March 22, 2011 - link
I noticed over and over in the review people came back to the point that the current app switching functionality is a very poor user experience. It's too bad Apple isn't enabling the multi-touch gestures for multi-tasking by default as they work very well and while they are not for general release it would be nice to see Anandtech weigh on them to see if they feel they should be included in iOS 5 or if they feel a better implementation is needed.Personally both my girlfriend and I have been using them and absolutely loving them. A four finger swipe up shows the multi-tasking bar instead of having to use the double-tap but 95% of the time a simple four finger swipe left or right is sufficient swapping between your most recently used apps. It makes it very easy to do something like copy a bit of text out of a web page, swipe over to Evernote and make a note, then swipe back to Safari and continue surfing.
It's really too bad Apple chose to hide them by default (my guess is they want to save them for the iPhone release to make iOS 5 look like a bigger jump in functionality) because they are a great and much needed addition to the iPad 2.
Mac Ike - Tuesday, March 22, 2011 - link
First of all this was great and extensive review,thank you very much! I have used Windows computers everyday at Work since Windows 3.1,I enjoy all Computers,but Macs are more stable more elegant,easier-to-use,and hold their value longer! I'm not trying to make Windows-users/lovers change to my preferences. I have not purchased an ipad yet,even though I can see many uses for it,and enjoy using iPads. I want ALL OF THE POWER I could possibly need with me,at all times,so I carry my 17-inch MacBook Pro for those times; when not practical I carry my iphone 4. Serious workloads might send me to my imac,it deprnds on ehere I am and what i need to do or what I can do in the environment that I'm in.Since I enjoyed the ipad 1,it only stands to reason that I would enjoy ipad 2,because the speed increase,cameras,weight-reduction,...can only enhance the experience! I am always amazed by the rude,idiotic,self-centered opinions and insults expressed on these Forums! If YOU don't want or need an ipad (or iPhone/Mac),then buy what YOU like! Why insult someone else,for THEIR DECISIONS or PURCHASES?? it's almost always a cheaper or alternative choices you can make. I give less than a Damn if you like another brand more,or feel that Apple's prices are too high!! If you want a cheaper computer,don't need a tablet,can't see the value of design/workmanship/elegance of OS &Hardware,hardware-software integration,good,buy your low-priced,cheap shit,and leave the rest of us alone,so that we can enjoy what WE LIKE! I don't ask any Apple-Haters or Fence-Sitters to purchase my products for me,so it's just amazing how people feel that you're an Apple-Fan Boy or Girl if you prefer Apple products! If I want a $60,000 Car,and you feel it's worth it(V-8 or not),and you can get a car for $20,000,why should your choice determine mine?? If you Windows-trolls don't like Apple-gear,why come to Apple-topics to complain about SOMEONE ELSE's choices?? Rude,immature,and Stupid!
rice2999 - Tuesday, March 22, 2011 - link
Dear anandThere is nothing about screen brightness setting to go with the battery life testing. Did you use 50% default brightness? Xoom screen is dimmer than ipad/ipad2. Though it can be argued, it is not exactly fair to compare battery life while the screen is on different brightness, since screen is probably the one uses the most battery.
I forget where I saw it, someone else actually used a meter to measure the brightness and adjusted the brightness to the same before testing the battery life.
Sabresiberian - Wednesday, March 23, 2011 - link
Every editor said what I've been saying all along about tablets - they are coolz toyz, but when people start trying to use them, they will find they aren't as handy as either a laptop or a smartphone and they'll be returned or be gathering dust somewhere. Except for niche uses, such as book readers and possibly media device controllers in the home, something like that, tablets are a fad - in my opinion, of course.That being said, they do have innovative technologies I think notebook manufacturers should pay strong attention to and add to their products (netbooks and notebooks). There are things the netbook/notebook can do a tablet's form factor prohibits (add a keyboard to a tablet and it really isn't a tablet any more now, is it?), but there is no reason the notebook should lack any feature a tablet has (except to save money on very low-priced budget models).
As to this thing having enough power to replace a "mainstream" computer if attached to a monitor and keyboard - right. I'll run out right now and buy one to play World of Warcraft on - or isn't that "mainstream" enough for you?
Won't be long now and a device this size will be able to replace what we consider to be a power-house PC these days - but then what will the power-house PC build be like then?
;)