Apple is developing its in-house graphics processing unit to replace its current provider Imagination. The PowerVR supplier stated the Cupertino-based company informed it on working on an independent unit for better control over the production. Half of Imagination's revenue comes from Apple and losing the iPhone maker as a client will be catastrophic for the company. Depending on how production goes within 15 to 24 months the cash flow from Cupertino is expected to stop. So we might see an A-series chipset with Apple-designed CPU and GPU as early as the 2018 iPhones. Imagination...
Source: http://www.gsmarena.com/apple_developing_inhouse_gpu_for_next_years_iphone-news-24346.php
