The Galaxy S9 is refinement of the S8 rather than a change. As the CAD schematics show, that thethe exterior of the new phones has barely is barely different from their predecessor.
The biggest change is that, the S9+ model will be 1.7mm shorter than its predecessor. The screen position, even the thickness of the earpiece have been changed slightly.
There will be one major change, however, the fingerprint reader on both phones is now positioned below the camera, much easier to reach and, of course, the Galaxy S9+ will have a dual camera.
(in mm). Height Width Thickness
Galaxy S8 148.9 68.1 8.0
Galaxy S9 147.6 68.7 8.4
Galaxy S8+ 159.5 73.4 8.1
Galaxy S9+ 157.7 73.8 8.5
Despite no apparent change in the sensor array above the screen, the Galaxy S9 will reportedly have IntelligentScan – a combination of facial and iris scanning. It remains a mystery , if this feature is mostly software-based or if there’s new hardware sitting under the hood.
Source 1 | Source 2