Despite the fact that it looks identical, the iPhone 4S is significantly different from its predecessor. To begin, it offers better performance without a big battery life penalty. Plus, we uncover display differences that Apple didn't bother to mention.
Looks can be deceiving. Yes, the iPhone 4S appears to be a spitting image of its predecessor. However, much about the latest iPhone update is actually different, beginning with its faster SoC that makes the new 4S more responsive.
In case you missed our inaugural coverage of the iPhone 4S, check back to Apple iPhone 4S, Part 1: More Horsepower, Better Hardware. In that piece, we ran preliminary input lag benchmarks and turned up an improvement as great as 50%.

Improved performance comes at a cost, unfortunately. This phone's battery dies approximately 7% to 8% sooner than the original iPhone 4. The good news is that you only take a hit when you performance CPU- and GPU-intensive tasks like decoding a video stream or playing a game. When you're just browsing the Web or listening to MP3s, battery life doesn't really change at all.
We're using the same tests here as you've already seen in our tablet reviews. For more information, read page 11 of Samsung Galaxy Tab 10.1: A Second-Gen Android Tablet.


Interestingly, recharge time doesn't change by any substantial margin. If anything, charging back up takes less time on the iPhone 4S. That's good news if you rarely sync your smartphone, and consequently have fewer opportunities to maintain a full charge.


Relatively-unchanged battery life is in sharp contrast to the wireless networking and gaming performance proffered by the iPhone 4S, both of which were covered in Part 1. This time around, we focus on Apple's improved camera hardware, the iPhone's display, and Siri.
In case you missed our inaugural coverage of the iPhone 4S, check back to Apple iPhone 4S, Part 1: More Horsepower, Better Hardware. In that piece, we ran preliminary input lag benchmarks and turned up an improvement as great as 50%.

Improved performance comes at a cost, unfortunately. This phone's battery dies approximately 7% to 8% sooner than the original iPhone 4. The good news is that you only take a hit when you performance CPU- and GPU-intensive tasks like decoding a video stream or playing a game. When you're just browsing the Web or listening to MP3s, battery life doesn't really change at all.
We're using the same tests here as you've already seen in our tablet reviews. For more information, read page 11 of Samsung Galaxy Tab 10.1: A Second-Gen Android Tablet.


Interestingly, recharge time doesn't change by any substantial margin. If anything, charging back up takes less time on the iPhone 4S. That's good news if you rarely sync your smartphone, and consequently have fewer opportunities to maintain a full charge.


Relatively-unchanged battery life is in sharp contrast to the wireless networking and gaming performance proffered by the iPhone 4S, both of which were covered in Part 1. This time around, we focus on Apple's improved camera hardware, the iPhone's display, and Siri.
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Summary
- iPhone 4S: Battery Life And Recharge Time
- Display Performance, Examined: The Benchmarks
- Display Performance, Examined: In Microscopic Detail (Literally)
- Display Performance, Examined: Color Gamut
- Camera Quality: Outdoors, Day Lighting
- Camera Quality: Outdoors, Night Lighting
- Camera Quality: Indoors, Good Lighting And Flash
- Camera Quality: Indoors, Poor Lighting
- Camera Quality: Video Performance
- Siri, How Smart Is Smart?
- After A Few More Days With Apple's iPhone 4S...
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If the display really is improved, then I think I'm going to have a hard time resisting the 4S (not that the 4's display was anything but great to me, but it's just more icing on the S cake). Good displays of any kind are rare in some (many) segments, but mobile devices wouldn't have great displays now had not Apple has pushed the market forward to IPS (and other higher quality type) panels in tablets and phones. If only they could do the same for laptops...
I believe the 4 also came with yellow/blue screens, if so the screen is nothing new.
you want a human comparable AI running inside a phone?
of course siri is basic. and so is all other AI.
The IP4S to me feels like an attempt by apple to lower expenses by leveraging existing architectures (IP4) and components (processor from iPad2) to drive profit margins.
The only reason someone with an IP4 should upgrade to an IP4S is that due to extreme demand you could probably sell back your IP4 for 350-400$ and know that your 4S will retain value for a long time as well.
The IP4S to me feels like an attempt by apple to lower expenses by leveraging existing architectures (IP4) and components (processor from iPad2) to drive profit margins.
The only reason someone with an IP4 should upgrade to an IP4S is that due to extreme demand you could probably sell back your IP4 for 350-400$ and know that your 4S will retain value for a long time as well.
Yes and no. I dialed back luminance for some other lab testing and we certainly still saw a difference in color temperature and gamma. This kind of goes back to the yellowing issue seen on some iPhone 4s (plural not 4S), which may be possibly related, but the replacements that Apple sent out were suppose to have their yellow tint fade away over time. At least that was the story... The bottom line is that there is a difference between the two models.
I suppose one could argue that its a cheaper panel. The one thing that the microscope shows is that it definitely is a different panel. This isn't just a weird chemical film that's plaguing a batch of Retina displays. This is actually a different panel at the subpixel level, because the subdomain structure has also changed.
7200 K is closer to the standard 6500 K, but without proper color calibration though, I'd say blue looks more natural. That's also reflected in the "standard calibration" most manufacturers use on their LCD displays.
I don't know about the only reason to switch. There certainly are many reasons not to use an iPhone, and I would be remiss to recommend one to everybody. In the US, the real problem is the inflexible carrier plans and the requirement to buy a data plan. Of course, this is a problem with all smartphones, so not just applicable to the iPhone.
Cheers,
Andrew Ku
TomsHardware.com
So far....WOW!
As for Siri; better than you may have indicated. "Conversing" is cute...for about 30 seconds. For me, being able to say "remind me to call Bill when I get home" or "what's on my calendar next Thursday" and get a good, if not perfect result is the takeaway for Siri.
Overall, this is an awesome device.
Yuppers. Very good eye for detail this one has.
Cheers,
Andrew Ku
TomsHardware.com
Which part of the battery test?
as for Siri,well its still in BETA,thats why it always may not work great
AT&T on both fronts.
Cheers,
Andrew Ku
TomsHardware.com
And what is that promise you stated at Part 1 review that you will included other Andriod devices? What a BIG disappointment! Lucky, I'm the only one who actually catch your word!
Matt
The AI of siri is not on the phone. The phone only relays what you've said to apple servers and then get a response.