Much like Microsoft is trying to wring every last drop of performance out of the Xbox One, Sony must do the same for the Playstation 4. A few days ago (May 19th) rumors surfaced that the PS4 would be on the receiving end of a ‘massive performance boost’ after Tidux brought up the subject on Twitter. We’ve speculated as to how this could be accomplished, and as it turns out it’s got something to do with the SDK of the PS4 and GPGPU rendering.
Originally there were several theories being banded about, but industry insider Ashan Rasheed (perhaps better known as Thuway) replying to someone on Twitter who was querying if the performance boost would be something Sony would announced . “Thats more to do with SDK’s improving. ICE Team is legendary with their work on the Sony tools side. You won’t hear about it,” started Thuway.
“Future SDK improvements on PS4 will focus on GPGPU rendering. This is when delta between PS4 and X1 will magnify,” he said.
Truthfully the fact this is SDK related isn’t surprising given SDK’s and toolsets are what ICE Team traditionally work on. Given how early we are in this generation (particularly since Project Morpheus isn’t released yet) it doesn’t make sense for Sony to start playing around with the PS4’s RAM reserves. This is truer still when you further consider than in just seven months there’s no way the PS4 could be close to having its potential fully tapped into.
Mark Cerny (the lead architect of the PS4) had said all along during several interviews the PS4’s GPGPU (compute) capacity would be the key to the consoles performance and this only further enforces his point and philosophy.
For those who’re unfamiliar with the PS4’s basic GPU architecture, it features 18 compute units, housing 64 shaders (ALU) each. This provides a grand total of 1152 processors capable of being used in a variety of different ways. The PS4’s GPU was expanded similar to AMD’s own Volcanic island desktop / desktop GPU line up by beefing up the ACE (Asynchronous Compute Engines) to eight from the previous two.
The Asynchronous Compute Engines queue and control the GPU’s task scheduling, effectively ensuring that compute data is being synced up to the current version in memory. Another important task they perform is the scheduling of when a task is performed so that it doesn’t interfere or drain away processing power from graphical tasks. For more information please checkout our article here. Another good source of info is AMD’s own official whitepaper (but they don’t cover the PS4 changes).
In addition to the increased number of ACE engines, they can queue more instructions (also raised from two to eight) meaning there’s a huge increase in the GPGPU control structure and performance inside the PS4. Shortly put, it can store more compute commands and has a larger number of units to tell compute (or graphic commands) how to run over the shaders. Don’t forget the PS4 also has more GPU performance than the X1 too.
Rounding all of this off is the PS4’s advanced HUMA memory architecture and of course the volatile bit compute structure which allows selective lines of code in the level 2 cache of the GPU to be flushed rather than needing to perform an entire Level 2 flush that would otherwise be necessary.
So, with ICE Team improving the SDK to allow games developers better libraries and an easier time of getting up and running we should see an advancement of GPU Rendering. GPU rendering is a fairly large field and could many a plethora of different tasks. Everything from Ray Tracing to having the GPU calculate certain types of physics or to help in AI and overall production of a scene in the game.