The Final Analysis
What have we learned by looking at the performance of three Radeon cards from the last three generations? Well, a few things, actually. Taking the Radeon HD 5850, HD 6850 and HD 7850 into account in this same-frequency face-off, the first point to note is that AMD has demoted the x850 line from the best single-GPU silicon to second-best GPU. This fact alone renders this an apples-to-oranges comparison.
Radeon HD 5850 is a better card than the name now suggests, and we can empirically prove this by how well it competes against the HD 6850 and HD 7850. Really, a 30-month-old card should be slaughtered by cutting-edge competition, even if the older GPU's clocks are raised, but this isn't generally the case. We feel comfortable in saying that Radeon HD 5850 owners, and there are many, shouldn't feel compelled to 'upgrade' to a Radeon HD 6850 or HD 7850 on the rather large proviso that the majority of their gaming takes place at 1,920x1,080 resolution and below.
Meanwhile, Radeon HD 6850 shouldn't really be in the same class as the HD 5850 or HD 7850. Perhaps a better name for it is the already-taken HD 6750? AMD understands its positioning and has reduced the buy-in price of the GPU silicon enough for partners to sell retail cards for £110... and even as low as £99 on special deals. It's a decent-enough card once the price dropped to the present £110, we suppose.
And this brings us nicely on to the Radeon HD 7850 2GB card that was paper-launched just the other day. It's a quality card that's the epitome of mainstream gaming - cool, small, and potentially very quiet - but widespread adoption may be stymied by the launch price of close to £200. It's almost guaranteed to drop to around £175 once NVIDIA retaliates with its own mainstream GeForce magic - which is currently wending its way through the manufacturing process and out to retail - and an HD 7850 costing £150, if it should come to pass, would represent an excellent investment.
The innate 'trouble' for AMD is that Radeon HD 5850 has scaled nicely with a catalogue of Catalyst driver updates. If in September 2009, just after the Radeon HD 5850's launch, we were asked to predict at what level a future HD 7850 would perform, chances are that our prognostication would think of it as more like the present Radeon HD 7950 - a meaty, wide and powerful GPU. Two reasons for the mismatch between prediction and reality can be attributed to AMD demoting the x850 line and the sheer excellence of the DX11-totin' Cypress architecture; it really was $259 (£185) well spent.
But this attempt at a coherent conclusion can also be argued the other way, too. Radeon HD 7850 is a plain better GPU than HD 5850, right? Any sane reader would go for it over venerable 5000-series technology if the choice had to be made right here, right now. HD 7850 manages to outshine an older card whose die is almost 60 per cent larger. That's indisputable, albeit fully expected, progress.
This critique of AMD's Radeon x850 cards is largely passé. The Radeon HD 7850 is what it is, not what we wish it to be. Really do consider buying it if retail examples drop to £150. Without taking sides, we need NVIDIA to drop a bombshell of a 'Kepler' GPU in response. Doing so will force AMD's hand into releasing the next iteration of Radeons that are absolutely bustin' at the seams with performance, value and efficiency.
Whatever the case, the next month looks set fair for AMD and NVIDIA to join battle using their respective cutting-edge GPU hardware technologies. Happy times.
