Apple's iPhone 4: Thoroughly Reviewed
by Brian Klug & Anand Lal Shimpi on June 30, 2010 4:06 AM EST- Posted in
- Smartphones
- Apple
- iPhone 4
- Gadgets
- Mobile
Incredible Battery Life
I’ve publicly praised Apple for its honesty in reporting battery life over the past couple of years, and the iPhone 4 gives me no reason to stop.
The 4 has an integrated 5.25Whr battery. That’s around 95% of the battery capacity of the HTC EVO 4G, despite having much lower power frequirements. It’s also a 16% increase over the 4.51Whr battery that was in the iPhone 3GS. This means at bare minimum, assuming the iPhone 4 doesn’t draw any more power than the 3GS, we should get 16% more battery life.
In reality, we get much more.
When Apple introduced the iPhone 3G it dropped battery life to a level that we’d been stuck at ever since. The 3GS improved battery life a bit through better CPU power efficiency but you still didn’t have enough juice to get through a day without charging.
The iPhone 4 changes all of that. The combination of a larger battery and a more power efficient SoC results in an incredible amount of battery life.
Our first test is a basic web browsing benchmark. We've scripted almost two dozen webpages to load, pause for 20 seconds, then forward on to the next page. None of the pages use any Flash. This process repeats until the battery is dead. Screen brightness on the iPhones was set to 50% and the screens remained on the whole time.
Battery life improved nearly 38% with the iPhone 4. It's clear that while the A4 improved performance, the real improvement was in battery life. This test has enough idle time where good power management and low idle power can really impact the results. There's simply no other similar smartphone that can touch the 4's battery life.
We then repeated the same test over WiFi instead of 3G:
Apple claims the iPhone 4 will last for up to 10 hours over WiFi, we measured just under that at 9.96 hours. The improvement here is only 12.8%, which tells me that we're nearing the limit of how efficiently Apple can manage power in WiFi mode. There's a wall that we're quickly approaching with this current architecture.
To measure talk time we play MP3s on repeat into the mic of a phone and use it to call the phone being tested. The process continues until the test phone dies. In this case the screen is allowed to go to sleep, as it normally would be if you were talking on the phone:
Apple promised up to 7 hours of 3G talk time with the iPhone 4. We measured 7.47 hours. That's an increase of 54.9% over the iPhone 3GS. While in a phone call the majority of the A4 SoC is powered down, so the efficiency improvements here have to do with how much less power the A4 consumes while off and the new Skyworks 3G modem (the iPhone 3GS used an Infineon modem).
In our iOS 4 review we looked at the impact multitasking had on the iPhone 3GS' web browsing battery life. I ran our 3G web browsing test while playing music through Pandora in the background. I repeated the test with the iPhone 4 for today's article:
We actually see our largest battery life improvement in this test. With a 57.7% increase in battery life over the 3GS, the iPhone 4 is not only more efficient at idle workloads but also when the SoC is constantly busy. The A4 SoC is rumored to be built on a 45nm process compared to the 65nm SoC used in the 3GS. With a moderate increase in clock speed we should be seeing a lot of the power savings that a full node shrink brings to the table.
The battery life offered by the iPhone 4 is spectacular. My iPhone 3GS could hardly get through a full day of work while traveling, I'd always need to hunt for an outlet before heading into my dinner meeting. I'm about to take my first trip with the iPhone 4 but I get the feeling that I might finally be able to make it through dinner.
Early reports of 20 and 30 hours of battery life are simply exaggerated. They're only possible if you let the phone idle in your pocket for the majority of that time. In other words, if you don't use the phone it lasts for a long time. While that's a testament to the platform's incredible idle power, the real world usage is good enough to stand on its own. It's better than any iPhone or Android phone I've tested thus far.
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Dark Legion - Wednesday, June 30, 2010 - link
Not to be a grammar nazi, but since I'm posting other things anyway..."Even Palm entered the race with a competent offering, and Microsoft isn't far behind."
Both the Evo and Incredible have 8GB built in + room for 16GB microSD (though they come with 8GB microSD?), and the Incredible also has dual LED flash.
SimKill - Wednesday, June 30, 2010 - link
I just printed this to a PDF, and its 75 freaking pages... Holy bleeding batman(in a good way) It's longer than even some magazines, 1 article.AWESOME
(I think it would be perfect on a Kindle...hmm next thing to buy :evilgrin: )
It's going to make for a nice evening read.
griffonu - Wednesday, June 30, 2010 - link
Really cool review! The first informative one in a general noise of non-sense and subjective opinions on the net./bow
Furuno - Wednesday, June 30, 2010 - link
I don't now what should I say about those $29.99 bumper case... It's even more expensive than my $15 "backup" phone...And I wonder why you're so excited about video call? isn't this is an old technology already? I've been doing this since high school with Nokia 3G's phone (forget the name).
I still prefer N900 tough, mostly because of it's Debian-based OS. As a programmer that's usually works with a Linux machine it's just incredible. Like, wow I can do apt-get install on my phone!
Oh, and thanks for the in-depth antenna issue explanation! Great article!
Griswold - Wednesday, June 30, 2010 - link
I'd rather like to know what apple says about the bumper cases. They cost them maybe a dollar at the most to make and they sell it for 29 bucks. Thats a fucking fat cash cow right there and it explains why they refuse to hand one out for free. What would you rather have? $2m spent in a couple weeks for satisfied customers or $56m profit from partly annoyed customers?(yea I read it, the issue is not really an issue and not everyone is going to buy a bumper case... its anecdotal)
JAS - Wednesday, June 30, 2010 - link
Indeed, Apple's pricing for its Bumper is outrageous. Who would pay $29 for a small piece of plastic? But if you are running a corporation, have a legal responsibility to shareholders to maximize profits, *and* customers are willing to buy a product at the listed price ... ?How long will it be until a third-party case maker introduces its own perimeter case for under $10?
kmmatney - Wednesday, June 30, 2010 - link
It won't be long at all. I bought by 3GS rubber case for ~$2 on dealextreme. It's now even cheaper:http://www.dealextreme.com/details.dx/sku.11687#op... full view
I agree that they should give away the cases for free, or heavily discounted . In any case, I don't anyone is crazy to not use a case on such an expensive device. You're going to drop it sometime.
Screammit - Thursday, July 1, 2010 - link
I'd have to agree with the video call bit, other phones (evo in particular) can do video calls over 3g AND can interface with computers through applications like Fring and Skype. I'm sure the video quality to only other iphone 4 users is stellar, especially over wifi, but isn't it a tad restrictive?archcommus - Wednesday, June 30, 2010 - link
I'm sorry, as much as I love Anandtech and Anand's in-depth and candid articles in particular, the bias here towards Apple is extremely strong. This article is night and day compared to the EVO review just posted. This is direct, interesting, discusses real impressions - EVO review was just a list of facts and things we mostly already knew. Honestly, it shouldn't have even been posted. I've gotten similar feelings about other Android reviews (Droid review 6 months after release? really?). I come to Anandtech to expect this level of quality in all articles, regardless of personal preference. As I said, I usually love your content Anand, but really the only thing I'm following of yours now are your SSD articles. All the rest of your attention goes towards Mac/iPhone.Griswold - Wednesday, June 30, 2010 - link
Have to agree, even though it assured me that my plan to get that phone is a good plan.Too much apple brown nosing.