Masaaki Tsuruta, CTO of Sony Computer Entertainment, says that the company is working on a system-on-chip (SoC) to underpin the product for "seven to 10 years".
The PlayStation 3 will be at least seven years old by the time its successor arrives, but is generally considered to have lasted longer than was originally expected. A firm launch for the fourth generation console - not to be called PlayStation 4 - was pushed out again late last year.
Its designed-in longevity is largely a matter of economics. The Cell Broadband Engine that powered the PS3 cost $400m to develop; the main SoC for the incoming console is likely to be a 3D stack incorporating thru-silicon-via technology and could be the first $1bn hardware design project.
“We have to look at two things,” Tsuruta-san says, “return-on-investment (ROI) and turnaround time (TAT).” The ROI issue, given the further costs of bringing a new PS to market (software, marketing, etc), means that Sony will be looking at a number of years and revs of the machine's insides.
However, its main rivals are breathing down its neck. Nintendo is understood to be running behind-closed-doors previews of its Wii U at this week's International CES in Las Vegas.
“So, you have to look at the current solutions and the current technologies and see how long you can extend those for the expected life of the product,” Tsuruta-san says. “You always want ‘perfect’ technologies but there are none. So, you look at what is available and try to get as close as possible to that goal. Even then, some of the things that we want are still five years away.”
At December's International Electron Devices Meeting, the Sony CTO offered a tantalizing glimpse of what the medium-term roadmap holds.
These features include more sensors and accelerometers, possibly even the monitoring of vital signs and eye movement to read emotions and then have software respond to that.
His presentation also foresaw the extension of the Augmented Reality technology being launched in the US this February on the handheld Vita tablet player. AR will initially insert CGI figures into a 2D rendering of the player's environment as captured by Vita's camera; for the future, Sony wants to move to fully immersive 3D delivered via lightweight glasses - a far cry from the clunky headsets of yore.
Still more visionary though was a vision of touch sensitivity that responds not just with vibration but the potential experience of, in his presentation, stroking a cat.
“For the haptics and the very advanced graphics, we are talking about those five years at least,” Tsuruta-san says.
The agenda he set out at IEDM was very much a call to arms for the silicon design community.
"Our strengths have always been in the integration," Tsuruta-san says. "We will have to work with a lot of third-party partners to make these things happen."
The headroom Sony will need to achieve all this - or even part of it, assuming that some things on its wishlist will not reach fruition in time - does help to explain why an announcement on the fourth generation PS is taking so long.
He describes the architecture in broad terms: "You are talking about powerful CPU and GPU with extra DSP and programmable logic."
This, and Sony's target of no more than 50ms latency even for 8k x 4k resolution at 300fps, clearly points to the need for a highly integrated TSV-based package - and so far TSV has stuttered in manufacturing for anything other than the stacking of like-on-like, typically memories.
In addition, Tsuruta-san has noted the difficulties in achieving viable yields at 28nm, though he believes that these problems are now moving towards a resolution.
"We are confident that we can now see a way and that we can use some of these advanced methods to create a new kind of system-on-chip. We think that there are the technologies today that can be taken to this project.”
Then there is the challenge of software. "We understand that for this, we will need to offer a very strong SDK. We will retain our own OS for the main games and support that with a development environment that is viable. For online and other features, we are also thinking of a simpler approach to a Linux-type environment than on the PlayStation 3," he says.
Sony is sticking to its knitting in one respect. It does believe that the future of high performance gaming will remain based on packaged media, although it will up support (and, importantly, security) for online features.
“We think that the core games will continue to be the most important,” says Tsuruta-san. “We don’t want to limit what people do on the console and we will have to do more on the server side, account for some aspects of thin client computing. Many people like the ability to play simultaneously, and when the networks are available we would like to open the platform up to more complex content through them.
“But we will have to wait for a while because current networks have limitations in bandwidth. A typical PlayStation console game is 50GByte – transferring those kinds of size over most of today’s networks won’t work. But more important is the experience. The networks cannot yet deliver it.”
This seems even truer when you connect together these aspects of the technology roadmap. Will the next generation PlayStation simply be a gaming console. Perhaps at launch, that will be its main selling point. But with Sony's commitment to a radically evolving machine - in part, surely a response to how the Kinect 'refreshed' the Xbox 360 five years after its launch - the roadmap describes a more fully-fledged virtual reality machine, long past the hype cycle and the Lawnmower Man.
As such, its implication for all future computing could be profound.