The Samsung Galaxy S IV is expected to pack a quad-core Exynos 5440 chipset whose CPU cores will use either 28nm high-K metal gate technology, or ARM BIG LITTLE architecture, which uses an energy-sipping A7 CPU, paired with a more powerful A15 units for heavier tasks.
Once again, we hear about a 5" 1080p AMOLED display gracing the Samsung Galaxy S IV. A 13MP camera and a 9.2mm waistline are mentioned as well. The latter has grown slightly over the Galaxy S III's in order to accommodate the S Pen.
If the S Pen report turns out to be true, the Samsung Galaxy S IV is bound to one up all its competitors as far as productivity is concerned. As is the case with most rumors, we would advise that you take all the above information with a pinch of salt.