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The new Apple iPhone 4 advantages surpass the 3 in a number of ways. Let's compare the 3 and 4 now to see what iPhone 4 advantages make it better and an improvement over earlier models.
First, the Apple iPhone 4 advantages in terms of display are that it includes a high-res Retina display which the 3 doesn't and a 960 by 640 resolution whereas the 3 has 480 by 320. The PPI (pixels per inch) has been doubled to 326 as a result, as well. They are both multi-touch.
One of the most notable of the new Apple iPhone 4 advantages which is heavily advertised and showcased in television commercials for it is the inclusion of "FaceTime", meaning you can see whoever you're talking to assuming they have the same phone and plan, as well. The 4 also includes dual-mix noise suppression, making it easier for whoever you are talking to to understand what you're saying regardless of the talking environment.
The camera has been significantly upgraded from 3 to 5 megapixels and now includes an LED flash, backside illumination sensor, and front camera with VGA resolution, none of which the 3 has. They both include autofocus and tap to focus.
Aesthetically you can now get the 4 in white in addition to the basic black.
Many of the Apple iPhone 4 advantages are battery related. Talk time has been bolstered from 5 to 7 hours on 3G and 12 to 14 on 2G. An extra hour is approximated both on 3G internet use and wi-fi and audio playback is up from 30 hours to 40 while video playback remains constant between both at 10 hours.
The Verizon Apple iPhone 4 is a 3G, CDMA/EV-DO Rev. A device, and due to limitations with the CDMA wireless technology, the device cannot simultaneously transfer voice and data over the cellular network. In other words, Verizon iPhone 4 users will not be able to make a phone call and then search for information on the Web while on a call at least when only connected to Verizon's network. This issue is not limited to the iPhone; none of Verizon's 3G CDMA devices support simultaneous voice/data transfer.
This fact may not seem like a big deal to existing Verizon users because most won't know what they're missing, but AT&T or T-Mobile 3G users switching to Verizon for the iPhone could very much miss the functionality I certainly do when I use a Verizon smartphone. The next version of the iPhone, expected in just a few months, could very well support LTE, which would provide for simultaneous voice and data transfer, and it will almost be a "world phone" that could be used on both CDMA and GSM networks in the United States and elsewhere.
Apple released the AT&T iPhone 4 on June 24, 2010, almost eight months ago. And in the world of technology, a LOT can change in eight months' time. Unfortunately, very little has changed about the iPhone 4; the iPhone 4 model being sold by Verizon does have a different cellular radio, a slightly modified antennae design than the original AT&T iPhone 4, as well as a shifted mute button...but that's about all that's been changed.
In other words, Verizon iPhone 4 buyers really aren't getting a "new" device, at least in my opinion. And the Verizon iPhone 4 offers few to no advantages over its AT&T brethren. With the arrival of the iPhone 5 expected this coming June assuming Apple sticks to its past release schedule of a new iPhone each summer it would be a wise move for most folks to hold off on signing a two-year Verizon contract for the iPhone 4. The iPhone 5 will surely pack a variety of cool new features and functionality that'll leave many iPhone 4 users craving more.
The iPhone 3G armv6 CPU had a VFP pipelined floating point unit that had a higher throughput than doing the same calculations in integer. GCC does support generating VFP instructions scheduled for pipelining. The iPhone 3GS and iPhone 4 armv7 CPU does not have a pipelined VFP unit, and is thus actually slightly slower at some floating point sequences than the iPhone 3G; but the armv7 processor is faster at vectorizable short floating point because it has the NEON parallel vector unit instead. Some Android device CPUs don't have any hardware floating point unit at all, so the OS uses software emulation for FP, which can be more than an order of magnitude slower than integer or fixed-point.
A general rule of thumb might be that if your algorithms can deal with only 24 bits of mantissa precision, and don't do a lot of conversions between float and integer, use short floating point on iOS. It's almost always faster.
But if you want to support older Android devices with your C code (using the NDK), use scaled integer.
If your app doesn't do a lot of number crunching, for a typical app that does under 0.1%, none of the above really makes a noticeable difference.
First, the Apple iPhone 4 advantages in terms of display are that it includes a high-res Retina display which the 3 doesn't and a 960 by 640 resolution whereas the 3 has 480 by 320. The PPI (pixels per inch) has been doubled to 326 as a result, as well. They are both multi-touch.
One of the most notable of the new Apple iPhone 4 advantages which is heavily advertised and showcased in television commercials for it is the inclusion of "FaceTime", meaning you can see whoever you're talking to assuming they have the same phone and plan, as well. The 4 also includes dual-mix noise suppression, making it easier for whoever you are talking to to understand what you're saying regardless of the talking environment.
The camera has been significantly upgraded from 3 to 5 megapixels and now includes an LED flash, backside illumination sensor, and front camera with VGA resolution, none of which the 3 has. They both include autofocus and tap to focus.
Aesthetically you can now get the 4 in white in addition to the basic black.
Many of the Apple iPhone 4 advantages are battery related. Talk time has been bolstered from 5 to 7 hours on 3G and 12 to 14 on 2G. An extra hour is approximated both on 3G internet use and wi-fi and audio playback is up from 30 hours to 40 while video playback remains constant between both at 10 hours.
The Verizon Apple iPhone 4 is a 3G, CDMA/EV-DO Rev. A device, and due to limitations with the CDMA wireless technology, the device cannot simultaneously transfer voice and data over the cellular network. In other words, Verizon iPhone 4 users will not be able to make a phone call and then search for information on the Web while on a call at least when only connected to Verizon's network. This issue is not limited to the iPhone; none of Verizon's 3G CDMA devices support simultaneous voice/data transfer.
This fact may not seem like a big deal to existing Verizon users because most won't know what they're missing, but AT&T or T-Mobile 3G users switching to Verizon for the iPhone could very much miss the functionality I certainly do when I use a Verizon smartphone. The next version of the iPhone, expected in just a few months, could very well support LTE, which would provide for simultaneous voice and data transfer, and it will almost be a "world phone" that could be used on both CDMA and GSM networks in the United States and elsewhere.
Apple released the AT&T iPhone 4 on June 24, 2010, almost eight months ago. And in the world of technology, a LOT can change in eight months' time. Unfortunately, very little has changed about the iPhone 4; the iPhone 4 model being sold by Verizon does have a different cellular radio, a slightly modified antennae design than the original AT&T iPhone 4, as well as a shifted mute button...but that's about all that's been changed.
In other words, Verizon iPhone 4 buyers really aren't getting a "new" device, at least in my opinion. And the Verizon iPhone 4 offers few to no advantages over its AT&T brethren. With the arrival of the iPhone 5 expected this coming June assuming Apple sticks to its past release schedule of a new iPhone each summer it would be a wise move for most folks to hold off on signing a two-year Verizon contract for the iPhone 4. The iPhone 5 will surely pack a variety of cool new features and functionality that'll leave many iPhone 4 users craving more.
The iPhone 3G armv6 CPU had a VFP pipelined floating point unit that had a higher throughput than doing the same calculations in integer. GCC does support generating VFP instructions scheduled for pipelining. The iPhone 3GS and iPhone 4 armv7 CPU does not have a pipelined VFP unit, and is thus actually slightly slower at some floating point sequences than the iPhone 3G; but the armv7 processor is faster at vectorizable short floating point because it has the NEON parallel vector unit instead. Some Android device CPUs don't have any hardware floating point unit at all, so the OS uses software emulation for FP, which can be more than an order of magnitude slower than integer or fixed-point.
A general rule of thumb might be that if your algorithms can deal with only 24 bits of mantissa precision, and don't do a lot of conversions between float and integer, use short floating point on iOS. It's almost always faster.
But if you want to support older Android devices with your C code (using the NDK), use scaled integer.
If your app doesn't do a lot of number crunching, for a typical app that does under 0.1%, none of the above really makes a noticeable difference.
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