When Sony introduced the trio of its high-end smartphones, the “Xperia Z5 Premium” stood out from the rest predominantly because of the one-of-a-kind 4K screen resolution. However, a new report citing a benchmark test said that the much-hyped 4K resolution might not have been fully utilized by Sony.

The Sony Xperia Z5 Premium features a 2,160 x 3,840 pixels screen resolution on a 5.5-inch IPS LCD display. However, benchmark tests suggested that the aforesaid resolution is used for only a handful of applications. Rest of the time, the screen reportedly sticks to 1,080 x 1,920 pixels for FHD resolution.

Going by the GFXBench benchmark results picked up by Tech Grapple, the device has been listed as featuring 1,080 x 1,920 pixels resolution, instead of the reported Ultra HD. As it turns out, the 4K resolution in the Xperia Z5 Premium will be put to use only when watching videos or viewing photos. Interestingly, when a user plays video games, the display apparently goes back to a FHD resolution.

Upon testing the video games scenario, Phone Arena reported that the 3D graphics performance specific to the Xperia Z5 Premium showed the device running at a relatively lower frame rate when compared to other Z5 series of devices.

As it turns out, the mini device Sony Xperia Z5 Compact apparently offers excellent 3D graphics performance. This handset reportedly ran at 37.8 fps in the Manhattan benchmark test. The flagship Sony Xperia Z5, on the other hand, clocked a test speed of 18.8 fps. In comparison, the Xperia Z5 Premium ran at 18.7 fps.