AMD has enjoyed plenty of room on our pages recently, what with all the talk of Mantle-this and HSA-that. We imagine the folks at NVIDIA have found it all quite bemusing, because for them the graphics card business hasn't changed: it's still primarily about offering higher frame rates for fewer watts in common DirectX-based PC games. Indeed, that's exactly what the green corner's all-new Maxwell architecture is claimed to deliver, starting with the GTX 750 Ti card that should be hitting stores today priced at $150 (or £115 in the UK). At the transistor level, Maxwell is no more efficient than Kepler -- we're still looking at a 28nm fabrication process, which is pretty standard by now. However, NVIDIA says it has figured out much smarter ways of distributing power across its graphics cores, resulting in a doubling of performance-per-watt. What does this mean in practice? Read on and ye shall discover.