By Jeremy Laird on May 8th, 2014 at 9:00 pm.
Existential crisis alert. AMD has been laying out its vision of the future of CPUs this week. And it calls into question the very meaning of what makes a PC. AMD is proposing parallel development of pin-compatible chips based on x86 and ARM. For most things I do with my PC, whether there’s ARM or x86 inside doesn’t matter much. I’m not bothered whether there’s an ARM or x86 chip underpinning m’Chrome browsing, for instance. But gaming is a very different matter. Whether for good or ill, being a PC with the x86 instruction set, Windows OS and DirectX API definitely means something when it comes to gaming. But if everything goes ARM or at least instruction-set agnostic, what happens to PC gaming? What does PC gaming even mean? Does RPS disappear in a puff of speculative logic?
Wait, I know what some of you are thinking. Not another bloody doom-and-gloom piece about the death of the PC.
Oh, OK. Guilty as charged. My opening ‘existential’ gambit and the ‘end of x86′ thing is perhaps too high on melodrama. But I promise, that’s largely not where I’m coming from. Instead, I’m simply pondering along the lines of, “OK, if that happens, what does it mean for the PC and for gaming?”
I’d rather think about this stuff early doors than wake up one day and suddenly realise it’s too late, even if it will likely take several years to shake out. It’s about keeping up to speed, not prognostications of inevitable doom.
Anyway, a quick précis of what AMD has announced is probably in order. In simple terms, AMD’s plan is to make both ARM and x86 chips from here on.
A certain high performance subset of these chips will be very similar despite the differing instruction sets. They’ll be pin compatible. They’ll offer AMD’s GCN graphics on-die and other shared non-CPU features. They’ll presumably have similar power consumption ratings. But you’ll have the choice of ARM and x86 CPU cores.
For us PC die hards, the most relevant parts of AMD’s announcement are its intention to develop its own high-performance 64-bit ARM core and a new x86 core.
For the first bit, that means AMD won’t just be taking ARM cores off the proverbial shelf (it will do that, just not exclusively). AMD will also licence the 64-bit ARMv8 instruction set and design its own custom CPU cores, codenamed K12, which could be used in something that resembles a current x86 gaming rig.
The second confirms AMD at least intends to keep developing new x86 cores. So this new strategy is not the beginning of the end for AMD’s x86 CPUs.
These new ‘ambidextrous’ chips, as AMD calls them, are due out in 2016 according to the announcement. Given AMD’s track record, you’d take that timing with a dollop of scepticism. But it’s the intention that matters, not the details of the schedule.
The upshot of all this is the possibility of various systems and devices that are identical in almost all regards save for the instruction set of their CPU cores. It’s at this point that you begin to wonder why anyone save for gamers would choose x86 in this scenario.
The context here is consumers, not academics or professionals demanding the ultimate in performance. For my money, our game boxes need to be derived from consumer tech, not chips aimed at enterprise and high-end academia. In other words, our game boxes need to be affordable.
In the past, x86 held a really clear performance advantage. That used to boil down to the whole ARM RISC vs x86 CISC thing where the ‘reduced’ ARM instruction set delivered awesome efficiency but modest performance and x86 broadly the opposite.
But in the last few years, ARM and x86 have been converging on common performance and efficiency ground. It’s an increasingly even contest.
The other big factor in favour of ARM is its status as a semi-open platform. Yes, the core instruction set is privately owned and controlled. But ARM’s licensing model is dramatically different from x86′s jealously guarded limitation to just two players, Intel and AMD.
Off the top of my head I can think of at least four outfits that currently design their own ARM cores. That means more competition which usually translates into more innovation, lower prices and the rest. Meanwhile, x86 chips for PCs are stagnating a bit and PCs look pretty pricey.
And you could ask whether a wholesale shift to ARM would be a bad thing even for gaming. Microsoft already does an ARM-compatible version of Windows complete with DirectX and D3D. Who cares about the CPU instruction set?
Well, you only have to look at the current limitations / awfulness of Windows RT to get a notion of how the transition from x86 to ARM for PC gaming is much easier said than done.
Then there’s SteamOS which is currently focussed on x86. Getting a broad library of games running on SteamOS x86 is a tough enough task, let alone thinking about a parallel ARM version.
No, it all gets very messy when you consider moving games across to ARM. The question, then, remains. What happens to PC gaming if the vast majority of non-gaming client devices have gone over to ARM? Can the gaming PC remain the sole x86 consumer device and be affordable enough to be relevant? Or will we have to go through a painful transition period as games too leap the x86-to-ARM divide?
Anyway, now you know what AMD has planned. What do you reckon to the whole ARM vs x86 thang?