Ps4 pro and Xbox one X

by Amar K. Hi, there

We knew the spec many months before its launch and gained insights into its core design from its system architect, but only now can we see the physical layout of PlayStation 4 Pro's central processor. The key takeaway? Add some memory controllers plus an extra four AMD Radeon compute units and the basic layout of the Pro's chip is very similar indeed to the physical make-up of the Scorpio Engine found within Microsoft's Xbox One X. Putting the two chips side by side reveals just how close today's consoles are, and how innovative design choices and more memory pushed Microsoft's hardware ahead of its rival.

Quite how we have photographic imagery of PS4 Pro's silicon is a fascinating story in itself. For a while now, we've been tracking the this Flickr account, which produces some truly remarkable work. Essentially, 'Fritzchens Fritz' takes a processor from its host mainboard, uses extreme heat to prise the chip away from its housing, then uses a remarkable process taking several hours to remove the layers of the chip, exposing the physical make-up of the processor itself, which is then photographed under extreme magnification. It's a process reliant on hardware donations, so from a somewhat selfish perspective, if anyone has a defective Xbox One X or PS4 Slim they can offer up for the cause, well, we'd love the chance to see the composition of these second-gen smaller, cooler 16nm processors.

But returning to the subject at hand, this new look at the Pro's physical layout offers up some interesting insights. For example, when the specs were first revealed, the number of hardware shaders looked very much like AMD's Polaris 10 processor as found in today's RX 580, which has 36 GPU compute units giving a total of 2304 shaders.

However, as per our conversation with Mark Cerny in the run-up to the Pro's launch, what we actually get is an entirely unique design: more of a butterfly arrangement, in fact with the original PS4 GPU mirrored, in effect. What is curious is that the area taken up by the second array of CUs is actually larger than the first. A quick count reveals 40 CUs in total (vs the 36 total on AMD's Polaris) with four disabled so that chips with minor silicon defects can be saved from the production line and still used in final hardware.

In the here and now, we can safely assume that both Sony and Microsoft are moving on to the core design of their next-gen successors, which become viable from a manufacturing perspective in 2019 when next-gen 7nm processor fabrication is expected to be mature enough to accommodate the demands of a new console launch. And with the arrival of AMD's Ryzen/Vega-based APUs, launching today (with Digital Foundry review coverage to follow), we may well be getting our first look at the building blocks of tomorrow's PlayStation and Xbox. Based on a revised 14nmFF process, AMD has integrated a quad-core Ryzen block and 11 Vega compute units in an area approximately 210mm². Scaling down those components to what we expect from the new 7nm process on a similar area used by PS4 Pro and Xbox One X offers up some fascinating options for the platform holders - something we'll be returning to soon.