The Xbox One and PlayStation 4 are more similar than any two consoles from competing vendors have been in decades, but as far as hardware specs are concerned, Sony has a decided edge. While both systems use AMD CPUs and Radeon 7000-derived, GCN-based graphics cards, the Sony system has 1,152 shader cores compared to just 768 cores on the Xbox One. Both chips are (or were) reportedly clocked at 800MHz, leaving Sony
with a 50% shader core advantage over its Xbox rival.
It's far too late in the cycle for Microsoft to do much about its GPU design, so the company has decided to tackle the problem by increasing GPU clock speed. In a recent podcast, Major Nelson confirmed that the GPU is currently running at 853MHz, up from 800MHz in the core dev kids. That's an increase of 6.6%, which will likely translate into real-world performance gains of 3-4%. As bonuses go, this one is pretty minor.
As for why Microsoft
would make the change, there are two reasons. First, it says good things about console yields that it can do so, and should help defray rumors that have circulated about catastrophic yield issues leading to an underclock or cache disabling (yes, those have been floating). The Xbox One
cooling system is extremely robust -- the CPU
fan is enormous -- so running the GPU a bit faster shouldn't be a problem. It's possible that Microsoft wants to continue nudging clock speeds upwards -- whether or not it can do so will depend on yield and power characteristics. The company could theoretically deploy a variable clockspeed technology that gives the GPU the option of pushing above a clock rate for short periods, provided TDP or temperature settings aren't exceeded.
The Cloud Question
With John Carmack publicly stating
that the two consoles are virtually identical, it's a safe bet that the PS4's higher clock rates won't result in dramatic game differences in anything but PS4 exclusives. Historically, developers have targeted the lowest common denominator; the majority of last-generation games were virtually identical across the two platforms. Sony may hope that by offering more graphics horsepower, it can entice more developers to build PS4
exclusives, but Microsoft still has its own cloud rendering offload it wants to push as an alternative. If the company can bring that off, the potential horsepower from a server bank far outweighs any console advantage -- but the latency factor makes this a big "if."
Still, we've already seen more evolution from Microsoft on major console features this gen than over the entirety of the last product cycle. Hardware specs are unlikely to change, but software capabilities and clock speeds are clearly still evolving.