Back before the Galaxy S5 was launched and rumors were swirling around its hardware, we heard rumblings of Samsung working on a GPU of its own for use in its Exynos chips. Today, that rumor has resurfaced – according to reports, Samsung has continued work on the GPU and managed to hire engineers from Nvidia, AMD, Intel and other companies, most of which are well-known in making GPUs for personal computers. Development has apparently been going on for a few years; it's not surprising that Samsung is working on developing a GPU, as using an in-house mobile GPU would free the company from having to license mobile GPUs from other chip makers (Samsung currently uses ARM's Mali series of mobile graphics.)
An in-house chip would also allow Samsung to make its Exynos chips more and more a fully home-grown project, though given the long time it takes to design chips from the ground up, it could be a while before we see the Korean manufacturer announce an Exynos chip with its own GPU. Given the fact that Samsung is moving more and more towards using its Exynos processors instead of Qualcomm's Snapdragon chip in many countries (thanks to the inclusion of on-board LTE on the latest Exynos variants), the company will likely take its time in making sure its first mobile GPU gets everything right and is capable of going head to head with the well-established competition.