The premium version of the iPhone 8 will have a 5.8-inch OLED panel when released in 2017, noted Apple analyst Ming-Chi Kuo of KGI Securities said in a new research note. However, the active display area will be between 5.1 and 5.2 inches for "specific design purposes".
What design purposes? Apple could implement a curved or wraparound display in a shakeup to the iPhone lineup.
In addition to the premium OLED iPhone, Kuo predicts Apple will release two LCD iPhone models in a 4.7-inch screen size and 5.5-inch screen size similar to the iPhone 7 line. It will be the first time Apple has broken away from a dual phone lineup.
Kuo wrote (via MacRumors):
We predict OLED iPhone will be 5.1-5.2", despite various market speculation. In terms of the display size of the OLED iPhone, current information from the upstream points to 5.8", while that from the downstream points to 5", which does not conflict, in our view. We predict OLED iPhone will adopt a 5.7-5.8" flexible OLED panel (with Samsung (KR) as the exclusive supplier). Nonetheless, for 'specific design purposes', the actual active area may be around 5.1-5.2". Other than the OLED model, we expect Apple to launch new 4.7" and 5.5" TFT-LCD iPhone models.
Bloomberg reported Apple is at the mercy of its four main suppliers for OLED displays, which could lead to supply constraints into 2018. Kuo predicts Samsung will be the exclusive supplier for the iPhone 8's OLED display.
In a separate note this week, Kuo said the OLED and 5.5-inch iPhone models will have dual cameras, while the 4.7-inch will stick with a single lens.
Given the iPhone 7 just launched in September, it's too early to tell exactly what Apple will launch. Notably, Kuo has pegged several previous Apple launches correctly, but we always encourage rumors to be taken with a healthy dose of skepticism.