When Sony unveiled the PlayStation 4 two months ago, many were impressed to see Mark Cerny fronting the presentation as lead system architect; the industry veteran first made his name by designing the classic Marble Madness at the age of 18, and has since been described as "the closest we have come to a modern-day da Vinci." Cerny hasn't spoken much about the PS4 since, but now a lengthy, in-depth interview with Gamasutra does a lot to explain the thinking behind the system's design.
"We didn't want the hardware to be a puzzle that programmers would be needing to solve."
Cerny traces the initial PS4 blueprint back to Thanksgiving 2007, when he read a book about the history of the x86 system architecture and decided it would be powerful enough for the PlayStation 3's successor. "The biggest thing is we didn't want the hardware to be a puzzle that programmers would be needing to solve in order to make quality titles," he says, explaining that many developers had difficulty with the PS3's unique Cell processor. "There was huge performance there, but in order to unlock that performance, you really needed to study it and learn unique ways of using the hardware." Cerny says the goal with PS4 was to employ a familiar architecture that would also have a lot of power. Addressing a question about whether Sony gave consideration to developers who would have to create games for multiple platforms — the next Xbox, codenamed "Durango," is widely believed to use a similar x86 processor to the PS4 — Cerny says, "When I say that our goal is not to create puzzles that the developers have to solve, that is how we do well in a multi-platform world."
PS4 uses a "supercharged PC architecture"
Cerny describes the PS4 design as a "supercharged PC architecture," and a big part of that is the 8GB of fast, unified GDDR5 memory that both the CPU and GPU can call upon. "If [a PC] had 8 gigabytes of memory on it, the CPU or GPU could only share about 1 percent of that memory on any given frame. That's simply a limit imposed by the speed of the PCIe. So, yes, there is substantial benefit to having a unified architecture on PS4, and it’s a very straightforward benefit that you get even on your first day of coding with the system." He believes that the design approach will result in a very future-proof console, and expects developers to eventually make use of "asynchronous compute" — harnessing the power of the GPU for tasks beyond rendering graphics, such as physics modeling. While most developers will probably use the GPU for graphics alone at first, Cerny says that, to maximize the PS4's potential, they should be exploring other methods of resource management by the midpoint of the system's lifecycle. This shouldn't be too difficult to adopt, either, with the PS4 development tools offering some "very simple controls" to adjust compute on the GPU.
Launch lineup will be "stronger than any prior PlayStation hardware"
On the subject of the PS4's games, Cerny says that the launch lineup will be "stronger than any prior PlayStation hardware" because of how easy the system is to develop for, and claims that game engines will take "weeks, not months" to port to the console from PC. That's not to say that there won't be challenges, however, and he addressed some potential pitfalls that creators might run into. "With graphics, the first bottleneck you’re likely to run into is memory bandwidth. Given that 10 or more textures per object will be standard in this generation, it’s very easy to run into that bottleneck," he says. "Our strategy has been simply to make sure that we were using GDDR5 for the system memory and therefore have a lot of bandwidth." Sony is also working on a PS4 version of its Razor performance analysis software, which is used in PS Vita development.
While Sony is yet to even reveal the box that all this hardware will fit inside, Cerny appears confident and eager to assure the world that the PlayStation 4 will right the wrongs that led to a difficult launch for its predecessor. But with the console's release scheduled for this holiday season, there's a lot of work to be done to make sure the finished product matches his works. "I have not been this busy in 20 years. It's nice," he says. "But, definitely, I'm very busy right now."
For more detailed discussion on the PS4's technical makeup, make sure to read the full Gamasutra interview.