Spec Analysis: PlayStation 4

The official specs are in for the PlayStation 4 and what we have is, by and large, confirmation of existing Digital Foundry stories - with one outstanding, exciting exception. At the PlayStation Meeting yesterday, Sony revealed that its new console ships with 8GB of GDDR5 RAM, not the 4GB we previously reported. It was a pleasant surprise not just for us, but also for many game developers out there working on PS4 titles now and completely unaware of the upgrade - a final flourish to the design seemingly added in at the last moment to make PlayStation 4 the most technologically advanced games console of the next gaming era.
"Sony has a hardware video encoder and it knows how to use it! The sharing of gameplay over IP was one of the impressive elements of the presentation."

PlayStation 4 official specs

Here's a look at Sony's released specifications for PlayStation 4. Aside from the substantial RAM upgrade plus the removal of dedicated compute resources, it's effectively a match for the leaked specs previously circulating.

Main Processor:Single chip custom processor. CPU is an x86-64 AMD "Jaguar", 8 cores. GPU is an AMD next-generation Radeon graphics engine rated at 1.84 teraflops with 18 unified Compute Units.
Memory: 8GB GDDR5 with 176GB/s bandwidth.
Hard Drive: Built-in
Optical Drive (read only): BD 6x CAV, DVD 8x CAV
I/O: Super-Speed USB 3.0, Aux (for PS4 Eye)
Communication:Ethernet (10BASE-T, 100BASE-TX, 1000BASE-T), IEEE 802.11 b/g/n, Bluetooth 2.1 (EDR)
AV Output: HDMI, Analogue AV out, optical digital audio output

From an engineering perspective, it's a remarkable achievement. Sony itself doesn't fabricate memory, it buys from major suppliers who advertise the parts available months (sometimes years) ahead of delivery, so we have a decent idea of what options the platform holders have on the table in creating their next-gen systems. The GDDR5 memory modules - the same used in PC graphics cards - are only available in certain configurations, with the densest option available offering 512MB per module. The startling reality is that unless Sony has somehow got access to a larger chip that isn't yet in mass production and that nobody knows about, it has crammed 16 memory modules onto its PS4 motherboard. To illustrate the extent of the achievement, Nvidia's $1000 graphics card - the GeForce Titan - offers "just" 6GB of onboard GDDR5.
The availability of these modules has also been something of a moving target throughout the development of PlayStation 4. In many ways, the genesis of the new console has been an exercise in Sony learning from the harsh lessons brought about by the PS3's custom architecture. The split RAM memory pool didn't work out so well and a unified RAM set-up was always considered a must for the new console. Early rumours suggested that GDDR5 availability could even limit PS4 to just 2GB of memory, with 4GB at one point looking rather optimistic. What changed at Sony and encouraged them to go all out with its final design is not clear, but the chances are it would have been well aware of the RAM advantage offered up by its upcoming Xbox competitor, which - certainly up to its beta hardware at least - features 8GB of more bandwidth-constrained DDR3. What shouldn't be understated is the amount of extra cash this is going to add to PlayStation 4's BOM (bill of materials) - this is an expensive, massive investment for the company.
So what does this mean for Sony and for next-gen gaming in general? First up, unless Microsoft has radically upgraded its graphics and memory configuration for Durango in the last nine months (an engineering nightmare unlikely to happen - it can't really add more chips as Sony has done), the PlayStation makers have less to worry about in terms of any direct hardware comparisons with their competition. GDDR5 latency is higher than DDR3 but the bandwidth advantage is substantial, while confirmation of the impressive Radeon graphics core puts to bed the era of PS3 developers struggling with sub-par GPU hardware. However, more importantly, many developers attest that it's the amount of RAM available that defines the longevity of a fixed platform. Historically, a console generation is typically defined by a 6-8x increase in technological power - both Microsoft and Sony have pushed the boat out with a 16x boost to system RAM over their current-gen predecessors - the strongest indication of any that these new machines are built to last.

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