Much has been said about Sony's upcoming PlayStation 4 although a large portion of the system still remains unknown. One thing we do know, however, is that the console is based on an x86 processor instead of a proprietary chip like the CELL processor found in the PS3.
Sony's Mark Cerny recently sat down with Gamasutra to discuss this decision. In short, the company moved to x86 to make it easier for developers to code on the machine. The eight-core CELL processor in the PS3 is extremely powerful but the problem developers discovered was that it was equally as complicated and difficult to utilize the full potential of the chip.
When you have studios like EA pushing out ports on an annual basis, there really wasn't any time to study the hardware and use it to its best ability. With the PS4, developers will be working with a familiar CPU and GPU which will make it easier to develop quality titles and port them to and from the system.
Cerny also touched on the system's unified architecture with 8GB of GDDR5, suggesting that it could help the PS4 trump a gaming PC in hertz-for-hertz performance. He said it was something that developers wanted so they delivered. As he explained, a PC with 8GB of GPU memory would only be able to share about 1 percent of that memory on any given frame. It all comes down a limitation of the speed of PCIe, he noted.
The GPU and CPU in the PS4 are on a single, custom chip created by AMD that is similar to an AMD APU. The memory isn't on the same chip but a 256-bit bus lets it access RAM at 176GB/s, eliminating any sort of bottlenecks. He said the strategy was simply to use GDDR5 memory and make sure it had plenty of bandwidth.