The future is fusion. But not yet...
Fusion chips are coming. So everyone keeps telling us. And you know what? They are undeniably right. The thing is, what happens in the future doesn't help up in the here and now. It isn’t much use if what's predicted for the future arrives too late to be relevant before the PC processor you buy today spirals off into obsolescence.
That's the fundamental problem for chips such as AMD's A10-7850K. In many ways, its CPU-GPU fusion of traditional processor with graphics functionality is a glimpse of how all PCs will be one day. It's how both of the latest games consoles from Sony and Microsoft already are, and, it can hardly be denied, how most of Intel's mainstream CPUs are now built. Every Intel CPU for the LGA1150 socket has integrated graphics, whether you like it or not.
But that doesn't mean it's actually good news from the end-user perspective, especially if you remotely care about gaming. The problem is that integrated graphics, even the very best currently available, still isn't great for gaming. And the 7850K has integrated graphics about as good as it currently gets.
The specs are pretty impressive. The 7850K's graphics subsystem has 512 so-called compute cores. They're not just any old compute cores either, they're GCN-spec cores, and thus essentially the same as AMD's top graphics cards and indeed the latest games consoles. In fact, the Microsoft Xbox One has 768 GCN cores in its graphics subsystem, which makes for an intriguing comparison.
Problem is, the Xbox also has a highspeed memory system to feed those cores, while the 7850K shares a standard dual-channel DDR3 memory controller between its four CPU cores and those 512 GCN cores. The upshot is that buying the 7850K as a single-chip gaming solution isn't a goer. It lacks sufficient graphics performance for serious gaming on its own.
Where things arguably get more interesting is if you pair it with a cheap graphics card in dual-GPU mode, combining the power of the integrated graphics with that low-end add-in board. On paper, it's quite a proposition. In practice, you’re still talking about modest gaming performance, but now you’ve added the vagaries and reliability concerns of a dual-GPU rendering solution. In short, it's not for us.
All of which means the 7850K probably has to make a decent case for itself simply as a CPU. That’s not exactly a given, especially when you consider that this ‘budget’ chip actually costs over £100. As a straight CPU, it even loses out to the dual-core Pentium chip in some tests. Basically, anything that majors on single-threaded performance looks a little ugly. But then you can say that about any AMD CPU right now. Indeed, as a CPU to pair with a powerful graphics card, it doesn't make much sense. Hook it up with, say, a GeForce GTX 780 and it will still drag your minimum frame rate in Total War: Rome II down to 27 frames per second. Yuck.
Admittedly, it’s better at multi-threaded tasks like video encoding than the cheapo Pentium chip. But so it should be at roughly twice the price. What’s more, because it’s manufactured on a bulk 28nm production process rather than performance-orientated silicon, the overclocking headroom isn't all that great, either. Its 4.4GHz maximum overclock is the lowest frequency here.
So, as a CPU for a proper desktop PC, it’s a struggle to recommend the 7850K. As the basis of a home-theatre PC with a tiny bit of light gaming on the side, it just about stacks up. But that’s quite a narrow niche you have to conjure up to allow the 7850K a realistic remit. Once AMD has sorted the memory bandwidth issue for its fusion-style processors, things will get interesting. Until then, they lack appeal as budget options for gamers and enthusiasts.
Lots of tech in a single chip; AMD GCN integrated graphics; decent stock clockspeed.
SPECIFICATIONS
CPU cores/threads 4/4
Process technology 28nm
Clockspeed 3.7GHz, 4GHz Turbo
CPU architecture Kaveri
Socket FM2+