Sony's rumored PS4.5 is now being dubbed the PS4K. Why the 4K? Well, in the last report they stated that Sony is aiming for this new PlayStation 4 “refresh” to handle 4K output, something the PS4 can only manage with photos and some videos. Well, in the newest report they state that the PS4K is real and it's coming.
Digital Foundry, a tech-oriented spin-off of Eurogamer, did a very detailed report on the possible hardware configurations of the PS4K. They make some common sense observations about Sony's options in regards to today's current hardware trends and tomorrow's possibilities.
They're entirely confident that Sony will stick with an AMD design, possibly even reusing the APU architecture of the PS4, but they think that there are a few possibilities that Sony will exploit to increase the power and workload capabilities of their mid-generation PlayStation console.
One of their options includes an overhaul to the GPU and CPU to get more power out of the system while maintaining some similitude to the PS4's design to still run the games on Sony's eighth-gen console. A risky and expensive move centered AMD's yet-to-be-released FinFET architecture and their Polaris GPU line-up. This could potentially put the PS4K in the running for actually rendering games at 4K, but even Digital Foundry admits that it's unlikely that AAA games would run at 4K with this solution.
As mentioned in a previous article, the CPU of the PS4 is the bottleneck at the moment. However, Digital Foundry sees a bigger problem with just upgrading the CPU and GPU: RAM. They believe that the GDDR5 shared memory infrastructure is no longer going to be fast enough for 4K texture and geometry streaming across the currently available bandwidth in the PS4.
Their second solution is a lot more practical, focusing on a more conservative upgrade to the GPU based on the 7xxx line of AMD's Tahiti GPUs with a higher clock rate and an overclock of the RAM. This second option is what they think will be a likely scenario since it's cost effective and doesn't change anything in the core architecture that would affect the PS4's current software library.
The main issue with their second option is that the CPU doesn't get much of a buff, and games still won't be able to run natively at 4K at 60fps with all the bells and whistles offered in today's crop of game engines.
The third solution is based on the possibility of shrinking the APU with the 16nm processor, and overclocking the existing core technologies while switching out the GDDR5 for “faster modules”. They believe this will be a cost effective and space-conservative method for getting a lot of power out of a small form factor without worrying about overheating issues. This third solution is also not expected to handle 4K gaming all that well, but it would be like dipping the toe in the water.
The form factor isn't so much the issue as is the backwards compatibility. Syber's highest-end Steam Machine running a single GPU is capable of 4K output but you'll have to pay around $1,600 for it. Sony will likely want to keep the PS4.5 (or PS4K) under $399.99. It seems to be the magical price point. So whatever their 4K solution is is going to have to be practical to today's standards of affordable hardware technology.
There is one option that Digital Foundry did not consider: Sony could abandon the “off the shelf” approach and go back to an original design that's compatible with existing PS4 software, a little like how Microsoft used some custom fittings for the Xbox 360 but still made it possible to emulate OG Xbox titles. There's no reason why they can't innovate the way the OG Xbox did back in the early aughts or the way the Xbox 360 did in the mid-aughts. It's just a matter of weighing cost efficiency versus 4K compatibility... and VR support.
Rumor has it that Sony will talk more about this PS4K at this year's E3 in Los Angeles.