After months of development it finally happened, PCSX ReARMed got a new GPU emulation code! It was designed and coded by no other but our own Exophase, and it believe me, it's good.
So what what's so good about this GPU code?
High performance - vast majority of games are now fullspeed at default 600MHz with no frameskip.
High accuracy - in many cases it's pixel perfect, a feat no other open source GPU has. It's output was compared with various real hardware dumps.
Makes heavy use NEON SIMD engine.
On the other hand, your max overclock for this emu will slightly drop again, so if you get crashes, lower it a bit. I suggest not to overclock at all unless it's really needed, i.e. it's not 100% fullspeed without overclock, which is only true for minority of games now.
This was sort of our team project with Exophase, where he designed in implemented the code, and I assisted him with hardware tests/dumps and general testing. You might notice quality increase for some games, like smoother color gradients (skies and shadows) because dithering is implemented now. As an example of graphic improvements, try Silent Hill, it's looking much better now, also underwater effects in MGS intro. However because it aims to be pixel perfect, it's still renders in game's native resolution, not pandora's.
Other than the new GPU it's bugfixes mostly. Download it from the repo (as usual):