In an interview with the Chinese smartphone manufacturer Huawei at Trusted Reviews the primary problem with 4K screens on a cell phone is identified as: “The power consumption would be so huge that your phone would last just half a day”.
While we at 4K rumors are normally in favor of all things 4K, this is the one area where it has not been demonstrated clearly enough that 4K is truly a worthwhile benefit on the relatively small screens of cell phones. The pixel density of 1080p is decently high already, and the 2K displays on phones are getting close to the limits of the eye can distinguish at normal viewing distances.
According to the leaked specifications listed at BGR the HTC M9 will take 4K video.
A rumor article at Value Walk about the Samsung Galaxy Note 5 speculates of the possibility of this phone being the first phone to have a 4K screen.
The value of a 4K on phablet screens is questionable. However, we eagerly wait to see the first 4K phone so we can evaluate it for ourselves.
None of our sources have confirmed that the Samsung Galaxy Note 5 will have a 4K screen and most the people we have talked to do not feel this makes sense as QUAD HD is still underutilized.
We will continue to watch and keep you updated on this rumor.