DigitalFoundry wrote up what
to expect from the PS4K, as well as what kind of hardware the device
might plausibly field. The question is this: What kind of advances can
Sony deliver, and how would it change the console’s capabilities?
4K gaming isn’t a realistic possibility
Let’s get one thing out of the way up front. Regardless of
whether Sony calls this a PlayStation 4K, there’s no modern GPU that can
pack into a console and offer a consistent 30 FPS at 4K within a $400
system price point. Teardowns of the original PlayStation calculated a
$121 bill of materials (BOM) cost for its various processors. Even if we
assume AMD’s next-generation Polaris architecture
could deliver a 2.5x performance increase, the power envelopes and raw
frame rates just don’t add up. Sony wasn’t willing to go deep into debt
on the PS4’s hardware at launch (the console’s estimated bill of
materials cost was $332 on a $400 launch price) and unless the company
changes that philosophy, it’s going to be significantly constrained in
what it can offer.
14nm should bring real improvements, but it’s not good enough in and of itself to drive the leap from 1080p to 4K. Our performance tests with Metro Last Light Redux illustrate why:
Even
top-end cards stagger when hit with 4K workloads. Granted, you could
improve these figures by dialing back detail levels, but remember — the
cheapest GPU on this list retails for over $300. Consoles are
historically better than PCs at squeezing maximum performance out of
lower-end hardware, but the GPU inside the PS4K still has to fit within
that $100 – $120 price point.
Radeon Nano power efficiency at default and 150% board power level.
The other problem with a 4K PS4 render target is that it
would probably require significant CPU and memory upgrades. Remember,
the entire point of a targeted console upgrade cycle
is that you minimize hardware changes to make backwards and forwards
compatibility as seamless as possible. Sony or Microsoft could get away
with using a higher-clocked CPU, but shifting CPU architectures
mid-stream would be a much more dramatic change. The PS4’s unified 8GB
of RAM might not be enough to support AAA titles at 4K resolutions,
which means you’d need either more GDDR5 or an APU that could support
HBM/HBM2 — and neither of those solutions is currently cheap enough to
fit within that aforementioned $80 – $120 price.
That said, there’s nothing stopping Sony from offering 4K
output support through a hardware upscaler. This would add latency, but
it could fulfill the 4K gaming bullet point without actually requiring
dramatically improved horsepower.
If “true” 4K isn’t available, what can Sony offer?
Sony’s best bet with any hardware refresh is to focus on
delivering significant gaming improvement at existing resolutions while
simultaneously supporting 4K media playback. Upgrade the Blu-ray player
to Ultra HD, add HDMI 2.0 support for 4K output, take advantage of the
HDR support AMD is building in next-gen hardware, and you’ve got a
potent upgrade option. 4K at 30 FPS might not be achievable, but
900-1080p at 60 FPS probably is. Again, take AMD’s claimed 2.5x
performance per watt improvement and apply it to the watts-per-frame
figures for 1080p — the final result would be 2.08W per frame, which
would allow 60 FPS output for a total power consumption of around 125W.
That’s well within console power consumption tolerances. At the very least, the PS4K should be able to hit a rock-solid 30 FPS at 1080p with no excuses or lag.
I’ve spent most of this article talking about the potential
for a GPU upgrade because I think that’s where Sony is likely to spend
most of its budget. In theory, a 14nm APU update could give the company a
chance to switch to Zen or at least to squeeze more horsepower out of
AMD’s Jaguar CPU. Obviously Zen is a black box at this point, but Jaguar
is a known quantity.
According
to Naughty Dog, cross-cluster cache latency on the PS4 is nearly as bad
as main memory latency. Faster L2 caches and a CPU upgrade could slash
that penalty.
The company could approach this from a number of directions,
including a unified 8-core CPU block (eliminating the sizable
performance hit currently incurred if one CPU block accesses the cache
of the other), increasing clock speeds from the current 1.6GHz to
something in the 2-2.4GHz range, and bringing the L2 cache clock up from
the current 800MHz to either full CPU speed or at least increasing it
to 1-1.2GHz to match the faster CPU cores. Other improvements could
include an SSD storage option as at least one SKU, possibly at a higher
price tag.
Would a PS4 with guaranteed 1080p output at 60 FPS and
support for next-generation Blu-ray standards be enough to interest you?
If not, what would it take?
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