Apple surprised us by announcing it
was launching a fourth-generation iPad just seven months after it
rolled out the Retina display-equipped third-generation iPad in March.
Though externally it remains almost identical to the third-gen
iPad—save its new Lightning connector, which replaces the 30-pin Dock
connector—internally Apple has revved up its processor. The company
claims the iPad 4 packs both double the computing performance and double
the graphics performance over the previous model.
We spent the weekend with an iPad 4 and iPad 3 in the Orbiting HQ,
benchmarking the new processor and spending time in various apps to see
if Apple's performance claims held up. Overall, it seems as though we
can take Apple at their word. But depending on the apps you use, you may
not notice a tons of improvement until developers learn to better
exploit the A6X processor's power.
This iPad looks very familiar
| SPECS AT A GLANCE: APPLE IPAD (4TH-GEN) | |
|---|---|
| SCREEN | 2048×1536 9.7" (264 ppi), "Retina" touchscreen |
| OS | iOS 6 |
| CPU | 1.4-1.7GHz Apple A6X |
| RAM | 1GB DDR3 |
| GPU | ImageTech SGX554MP4 |
| STORAGE | 16, 32, or 64GB NAND flash |
| NETWORKING | 802.11a/b/g/n, Bluetooth 4.0 |
| PORTS | Lightning connector |
| SIZE | 9.50×7.31×0.37" (241.2×185.7×9.4 mm) |
| WEIGHT | 1.44 lbs (652 g) |
| BATTERY | 43 Whr |
| STARTING PRICE | $499 |
| PRICE AS REVIEWED | $599 |
| SENSOR | Ambient light sensor, Accelerometer, Gyroscope, Magnetometer |
| OTHER PERKS | 12W charger |
Again, the iPad 4 is, from the outside, nearly identical to the last-generation iPad before
it. It shares a similar aluminum unibody shell, with a flat bottom and
sloping edges; the headphone jack, buttons, volume rocker all appear
identical; even the 5MP autofocus camera at the rear is the same.
There's not really much new to say about the design, except that Apple
has swapped out the aging 30-pin Dock connector for its new Lightning
connector, which is being phased in as the standard connector for all
its mobile devices.
(With this change, only legacy devices still have the 30-pin Dock
connector, including the iPad 2, iPhone 4S, iPhone 4, and iPod classic.)
Like the iPad 3, the revised iPad 4 measures 9.50×7.31×0.37 inches
(241.2×185.7×9.4 mm), weighs 1.44 lbs (652 g), and is covered on top by a
large piece of fingerprint-resistant Gorilla Glass. Given the devices
are so similar on the outside, we're even going to quote from our iPad 3 review:
"We don't mind the design—the iPad has already seen wild success in its
previous forms, and this one is certainly functional and attractive.
Apple tends to lean toward the conservative side when it comes to
radical cosmetic redesigns in immediate succession to one another."
This iPad could not be more conservative when it comes to design. If
you're looking for something different, you'll have to consider the iPad mini. Its design more closely mirrors the newest iPod touch,
and we expect design cues from those devices to show up in a future
full-size iPad. For now, this is exactly what you have seen on store
shelves for the last seven months.
It's what's on the inside that counts
The real differences in this newer iPad are on the inside. The
front-facing camera has been upgraded to a 1.2MP still, 720p video
FaceTime HD camera. The LTE radios in "Wi-Fi + Cellular" models have
been updated to newer Qualcomm chips that have wider compatibility
outside North America, and Apple has replaced the A5X processor with a
new A6X design. Apple promises "up to twice as fast" Wi-Fi performance,
but as our friend Glenn Fleishman noted, Apple's claim is based on theoretical performance never achieved in real-world scenarios.
Our review unit is an off-the-shelf 32GB Wi-Fi model. LTE-equipped
models aren't shipping for "a few weeks" in the US, according to Apple.
(But we don't expect that LTE performance would really be any different
from the previous model.) While the newer Qualcomm baseband chips are
more power-efficient, our testing with the iPad 3 suggested the LTE chip
didn't use very much power relative to the 2048×1536 pixel Retina
display. We don't think there will be much impact for US users.
International users, however, will likely see real improvement. The
older LTE chips in the iPad 3 were only compatible with LTE networks in
the US and Canada. Users in other countries were limited to HSPA+
speeds. This particularly riled users in Australia and Sweden, where
Apple ended up facing some sanctions for
calling the devices "Wi-Fi + 4G." Though the newer LTE chip makes the
iPad 4 compatible with carriers in most countries with LTE service, you
can see why Apple switched to the more generic "Wi-Fi + Cellular" name
for cellular-equipped iPads.
The upgraded FaceTime camera is functionally the same as the one in the
iPhone 5 and fifth-gen iPod touch. It uses a backside illumination
design, so it takes better images and video in low light. The resolution
is much improved for both stills and video, though you may not always
see it in FaceTime video chats depending on bandwidth limitations. For
taking the requisite Facebook profile pics or snapshots of friends out
on the town, however, it certainly suffices. It's not a mind-blowing
change, but welcome nonetheless.
We expect Ars readers are probably more interested in the A6X processor. This new high-powered mobile processor combines two custom-designed ARMv7s-compatible cores, just as in the A6 processor in the iPhone 5. However, Apple has significantly boosted its graphics processing power.
The A5X in the iPad 3 has 4 Imagination Technologies SGX543 GPU cores clocked at 250MHz. For the A6, Apple combined three of these cores with a slight clock boost, to 300MHz, to give the A6 a boost in graphics power—roughly on par with the A5X.
To achieve twice the performance of the A5X, however, Apple did more than boost clock speed, as we expected. Instead, Apple apparently employs four SGX554 cores,
which have double the number of arithmetic logic units compared to the
SGX543 cores. Along with a streamlined memory access design and a slight
clock increase over the A5X GPU cores, Apple was able to achieve a
promised 2x performance boost.
Apple was able to use the larger SGX554 cores thanks to a switch to
Samsung's 32nm process from the 45nm used for the A5X. With plenty of
die space available, Apple was able to essentially add more GPU hardware
to the mix. As we'll see shortly, in terms of raw performance the
change has paid off.
