Apple's iPad - The AnandTech Review
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on April 7, 2010 9:39 PM EST- Posted in
- Smartphones
- Mac
- Apple
- iPad
- Mobile
Honest Apple: Battery Life
I mentioned this in my iPhone 3GS review and I believe it bares repeating: Apple's battery life estimates have been ridiculously accurate over the past couple of years. I swear Apple must have my office bugged because my battery life numbers almost always equal theirs and they have no access to my test files.
To test battery life on the iPad I ran a modified version of the process I use for smartphones. I use the WiFi connection to browse a series of 20 web pages varying in size, spending 20 seconds on each page (I timed how long it takes me to read a page on Digg and came up with 36 seconds; I standardized on 20 seconds for the test to make things a little more stressful). The test continues to loop until the battery dies. This test is designed to simulate a relatively heavy, but realistic data load on the phone. We're stressing the WiFi radio, SoC, memory and display subsystems here. This should also be the sort of battery life you get when you are using any apps that use data (but not 3D acceleration). The display brightness was set to 50% on the iPad.
That's the test I use for smartphones, but to make it a little more stressful on the iPad I continuously played music using the iPod app, one of the only apps that's allowed to run in the background. I also told the mail app to automatically check my AnandTech email account every 15 minutes. I get a good amount of mail so this constant checking would add another realistic component to the workload. I also ran this same test on ASUS Eee PC 1001P:
The iPad came in just shy of Apple's 10 hour claim. At 9 hours and 45 minutes, it's long enough to get you through the greater part of a day. But calling Apple's battery estimates conservative is misleading. A single charge won't last you all day.
The iPad does last longer than ASUS' 1001P, however ASUS tells us that the 1005PE will buy you another 2 hours of battery life for an extra $79.
What about watching movies? Our resident smartphone expert Brian Klug put together a 6 hour loop of The Bourne Ultimatum. This was from a 1080p source but re-encoded using Handbrake's Normal profile resulting in a 1.3GB 720p rip that was looped three times.
I imported the movie into iTunes, synced it to the iPad and looped the already 6 hour loop until the iPad died. Display brightness was set to 50%, auto brightness control was disabled, automatic email downloading was also disabled.
Video playback is actually a fairly light use case. In these SoCs there's usually a dedicated video decode block, most likely the PowerVR VXD (same as in the iPhone 3GS). This block decodes each frame and sends it to the display output engine. The only things working in this case are parts of the CPU, the video decode engine, memory bus and the display engine. There's no 3D rendering and the vast majority of the CPU is idle. With this in mind, it's no surprise that the iPad can last 13.6 hours when playing back a 720p H.264 movie.
| Apple iPhone 3GS | Apple iPad | ASUS Eee PC 1001P | |
| H.264 Video Playback | 9.5 hours | 13.6 hours | 5.3 hours |
The iPhone 3GS however can almost hit 10 hours performing the same test. This gives you an idea of how much power the display is consuming on the iPad. The netbook doesn't stand a chance by comparison. The iPad was made for watching lots of movies on a single battery charge.
My final battery life test was a 3D gaming benchmark. I ran Real Racing HD on the iPad (and Real Racing on the iPhone) until the devices died. The cellular network was turned off on the iPhone 3GS and brightness was set to 50%.
Anything GPU intensive is going to be the worst case scenario for these SoCs. Here we’re stressing the CPU, GPU and memory subsystem. The added load is reflected in the battery life numbers:
| Apple iPhone 3GS | Apple iPad | |
| 3D Gaming | 3.9 hours | 8.8 hours |
The iPhone 3GS approaches 4 hours, while the iPad manages almost 9 hours while gaming. I’d also consider this to be a best case scenario gaming benchmark. A more intense 3D game could easily drop these numbers even further.
Facebook
Twitter
RSS
108 Comments
View All Comments
zodiacfml - Thursday, April 8, 2010 - link
Another quality review, useful as trying the device myself.I'm not buying Apple products but you touched on features that it should have.
One is the ability to stand on its own to function as a picture frame, movie screen, and reader while someone is eating or something else.
Support for mouse device and keyboard when it can already stand on its own.
Support for uploading media such as video and photos from either flash cards or directly from cameras. it is such a good device to use with cameras.
one more thing, they could get the intel atom cpu once it gets to a smaller process to improve size and energy efficiency.
Spivonious - Thursday, April 8, 2010 - link
Anand, I love your writing and have read the site since the GeoCities days, but please learn the difference between "lay" and "lie".crimson117 - Thursday, April 8, 2010 - link
My biggest pet peeve with the iPhone UI is the lack of an indicator for when an app is visible but busy processing something and not currently accessible.The default Notepad app on the iPhone 3G is a great example - as soon as you tap the icon, the yellow Notepad interface pops right up. However, it actually takes several seconds to finish loading until you can tap to edit a note or tap the (+) sign to start a new note. There's no indicator at all of when the loading is complete - you have to keep tapping periodically until it finally works.
The same is true for resizing a web page using multitouch - there's no indicator that your input has been received but it's going to take a few moments to make it happen.
In Windows 7 when an app is "thinking" and thus you can't interact with it, your mouse pointer becomes a a little circle (aka an hourglass). If an app is ever extremely busy thinking, the app may even gray out to indicate that even Windows can't get it to respond at that time.
The iPhone's lack of this feature just smells of Apple trying to make the device appear on the surface to be more responsive than it really is. Perhaps you'll question whether you tapped correctly, and won't realize that the device is just slower than you expect it to be.
archcommus - Thursday, April 8, 2010 - link
This article, like your others, despite being 22 (!) pages long, is a quick, refreshing read. It feels more like you're talking about your experiences and less like you're writing an article as a journalist (which can make some other long reviews a little boring). Also seemed pretty unbiased and highlighted the good and bad. Another solid article, thanks.Mumrik - Thursday, April 8, 2010 - link
Hehe, this isn't a big deal - it's just amusing:"Although there's no mute button, holding the volume down rocker for 2 seconds mutes the device instantly."
Nope. Sounds to me like it takes about two seconds to mute the device :)
AstroGuardian - Thursday, April 8, 2010 - link
Good one. My thought exactly...leospagnol - Thursday, April 8, 2010 - link
I'm planning to buy one of them when I travel to US next month. THe Eee 1001P is $ 280.00, and the iPad $499.00 at least. I usually read more than I write during classes and I have wifi available during class. I'll probably buy the Eee, but wich do you think suits this task best?Mumrik - Thursday, April 8, 2010 - link
Imagine the iPad lying flat on your desk and then imagine the position you would have to sit in all lecture long if you wanted to be able to write.Then imagine how much of the time you'd have to look down at what you were writing because you didn't have the physical response of a keyboard to make touch typing easy.
Now imagine not being able to multitask.
It would not be a difficult choice for me - Anand said it himself - the iPad is generally not a laptop substitute.
videogames101 - Thursday, April 8, 2010 - link
I love the M3, great episode there.Good to know I can watch it on the iPad, lol.
AstroGuardian - Thursday, April 8, 2010 - link
As far as i remember, this was not mentioned in the review (the overheating problem):http://www.dailytech.com/article.aspx?newsid=18075
Personally i don't think it's worth commenting. It's not just the iPad but all other electronic devices will overheat when put out on the sun. And i wouldn't call it overheating but more like misuse.