One of the interesting facts to come out of Sony's PS4 announcement is that the new console is, for all intents and purposes, a PC. This isn't the first time a major manufacturer has launched a console based on commodity PC hardware -- Microsoft's original Xbox
was a Pentium 3 with an onboard GeForce 2 GPU -- but it's a definite first for Sony. Both the PS2 and PS3 eschewed commodity hardware, opting instead for expensive technology Sony had a direct hand in developing.
PS4's Killzone Shadowfall title
Thus far, the PS4 has one capability that outstrips anything a traditional PC can offer -- memory bandwidth. The PC version of AMD's Jaguar is, according to AMD's own technical documents, a single-channel architecture designed for DDR3. The PS4, on the other hand, has a unified 8GB of GGDR5 with sustained bandwidth of 176GB/s. The simplest way to square these figures is to assume that the 18 CU Radeon core actually handles communication to main memory. What this means for CPU-GPU cross communication is less certain. It's possible that the GCN-based Radeon inside the PS4 actually implements some of the HSA advances AMD has previously forecast for its future products. It's also possible that AMD
did, in fact, overhaul Jaguar's memory controller to make the CPU the focal point for communication. Alternately, the IMC might be a separate package with ties to both CPU and GPU.
A 176GB channel to main memory, however the PS4
gets there, implies a 256-bit bus clocked at 1375MHz; the 1.84 peak TFLOP measure for single-precision floating point and Sony's statement that the chip packs 18 compute units tells us that the PS4's GPU has 1,152 cores. This can be mathematically extrapolated by comparing the clock speeds and floating-point performance of other GCN processors.
The PS4's closet PC cousin is the Radeon 7870 GHz Edition. That chip is based on the Pitcairn XT and runs at 1GHz with 1280 cores, a 256-bit memory bus, and 153.7GB/s of bandwidth. Tweak the core by disabling two Compute Units, lower the clock speed, and bring the memory clock up to 1375MHz from 1200MHz, and boom -- there's your PS4 SKU. Obviously AMD has done some custom work on the SoC design, but even Sunnyvale only refers to these products as "semi-custom."
Sony's new Dual Shock controller is a touchscreen-equipped option.
With Microsoft's Xbox already widely expected to use a GCN-derived graphics card, porting games across various consoles should be markedly easier than it used to be. GCN will be a common target between all shipping hardware save for Nintendo's Wii U. The console/PC unification, however, goes much farther than the underlying hardware. Sony and Microsoft are both emphasizing social integration, connectivity, and second-screen gaming, while companies like Valve and Nvidia's Project Shield push the idea of moving PC entertainment experiences to televisions and handhelds respectively.
What we're seeing here is a convergence of entertainment experiences that blur the line between PC and console by offering gamers the option to seamlessly switch play from one location to the other. The idea of taking your work or data access with you is a very PC concept and it existed long before the advent of cloud computing. The term "Thin client" was invented more than a decade ago to refer to such systems, though machines were still tied to a particular network or server.
The future of gaming looks to be an interesting one, and hopefully we'll see better quality console ports thanks to the similarities between console and PC hardware. That question will rely on the developer tools from Sony
-- if the companies build their support products well, it could streamline the entire development process.