Nowadays phones are coming out with very high pixel densities which make it almost impossible to view individual pixels from the naked eye. The human eye can differentiate individual pixels if the display is lower than 200ppi. This resolution was pretty common until a couple of years ago but since then smartphone displays have been improving on that front.
The possibility of seeing individual pixels
However when the resolution is further increased, we need to strain in order to make out individual pixels. After 300ppi, our eyes cannot normally see individual pixels on the screen. The Sony Ericsson Xperia X1 was released in 2008 and it was the first smartphone to break the 300ppi barrier with a screen of 312ppi resolution. The iPhone 4, released in 2010, also had a 326ppi display. Several other phones are also about to come out with similar pixel densities.
This means that as more and more smartphones on the market have 300+ dpi screens, developing further for even higher resolution displays is useless. A reason for this is that it would not make any difference to users if a screen has 300dpi or 400dpi. Although a difference of the screen resolutions can be seen by using a magnifying glass, it is essentially a useless difference in everyday life.
Higher resolutions of smartphone displays
Smartphone displays are nowadays increasing in size. 4.3 inch and comparative displays are becoming more and more common on smartphones. In order to achieve a high dpi on such a large screen, the resolution has to be a very high one. When 300dpi will be achieved on these smartphone displays, the resolution will already be sufficiently high enough to start taxing the hardware capabilities of the device such as the processing power.
Thus if smartphone displays are further developed and lead to them having even higher pixel densities, the smartphones will perform slowly and this will not really be a worthy trade-off as people would not see the improvements in the display. Thus, once 300dpi has been reached on most smartphones, further improvement of the screen’s dpi is useless.
Currently the fastest processors in the phones already on the market are 1GHz Snapdragons. However there are several more smartphone processors on the brink of release. Several 1.2Ghz Hummingbird processors are also coming up along with the hotly anticipated Tegra 2 dual-core processors. There are several reasons why there is a special need for these faster processors in the future.
Additional smartphone features
There are several smartphone technologies that are getting common by the day and require a pretty powerful processor. An example would be the HDMI port which has started appearing on several phones and requires quite a lot of power in order to transmit high definition video to devices such as televisions. As the time goes by, this feature will become quite common and the devices will be required to run other applications while outputting video.
Until now most of the phones having HDMI can output video at 720p. These phones utilize the current generation of processors and cannot fully output content at 1080p. However newer phones such as LG Optimus 2X, which has a dual-core Tegra 2 processor, can easily output 1080p content to any display. This means the extra horsepower in the processor department is definitely required to run newer technologies smoothly.
More demanding software
As the time goes by, smartphone software is also become more and more demanding. Higher resolution games as well as applications are coming up every day which need extra processing power to run smoothly. Smartphones are increasingly becoming convergence devices and several different software may be running simultaneously on the device such as a GPS app, a music player and another application such as a web browser.
Along with that several device manufacturers have skinned the operating system that they use which slows down performance. Thus these phones need faster processors to run the modified code efficiently. If they modify the user interface extensively without upgrading the processor, the device experience would be a lackluster one.
Newer technologies coming up in mobile phones
Mobile phones will start getting much more advanced technologies when the processors reach the required mark. Ability to play 3D content is near the top of the list. As applications have started appearing on mobile phones for renting and playing movies through cloud storage, device manufacturers will push to get 3D content to work on their devices. This 3D content can be over HDMI or even built in 3D displays. This would require quite a lot of processing power.