It comes as no surprise to see Nvidia graphics cards dominating the top end of the graphs, as Nvidia has ruled the folding performance charts for a few years now. Before the Nvidia fanboys jump for joy, this isn't because AMD's hardware is inferior per se. Essentially, Nvidia graphics cards are thought to be more suited and better supported for folding, which is why the split is so evident in the efficiency graphs. There are numerous explanations depending on who you speak to, but this is what Stanford has to say on the matter:
'Due to a difference in the implementation (in part due to hardware differences), the ATI code must do two force calculations where the x86, Cell, and NVIDIA hardware need only do one. This increases the overall native FLOP count for ATI hardware, but since these are not useful FLOPS in a sense, we did not include them in the x86 count.'
The star of the show in terms of raw speed is the GeForce GTX 590 3GB. A ppd of 25,780 is epic for a single graphics card. Interestingly, the fact it costs a fair bit less than two GTX 580 1.5GBs means that it also topped our ppd per watt power efficiency graph, churning out a ppd of 61 for every Watt of power.
The GTX 560 Ti 1GB wasn't far behind in terms of folding power efficiency, though, and was considerably more efficient than the GTX 460 1GB and GTS 450 1GB. The latter makes for the most cost-effective purchase, though, recording a ppd of 87 for every pound spent.
The GTX 560 Ti 1GB is very power-efficient, fairly cost effective and very overclockable. It's ideal for gaming and folding
A year ago, the GTX 480 1.5GB was making waves in our folding graphs, and the same is true again, most notably in the cost efficiency graph. It came third here, producing a ppd of 71 for every pound of its recently reduced price tag. It currently retails for £200 - a fraction of what it cost at launch and over £150 less than the GTX 580 1.5GB ,which only managed an additional 2,297 ppd on top of the GTX 480 1.5GB's ppd of 14,195.
The only 'old' graphics card worth talking discussing is the GTX 260 (rev 2). As it's no longer available, we used an average eBay price to gauge its cost efficiency (around £90). In short, it was the least power efficient Nvidia graphics card for folding, although it did come fourth in the cost efficiency graph - you would be better off with a warranty, though, if we're honest.
We'll doubtless see plenty of folders using the GTX 590 1.5GB. However, given the heat it produces when under load, water-cooling would be essential for 24/7 folding. Even then, with so many stories of GTX 295s cooking themselves when used for folding, we're reluctant to recommend a dual GPU graphics card for folding at all. In addition, even though it's the most power-efficient card for folding, our system drew an additional 118W with the GTX 590 installed when compared to the GTX 580 1.5GB, and drew more than twice as much from the wall than when the GTS 450 1GB was folding.
If any graphics card stuck out at us, it was the GTX 560 Ti 1GB. It came second in the power efficiency graph and fifth in the cost efficiency graph. To get anything significantly more power-efficient would mean opting for a GTS 450 1GB, which recorded barely half of the ppd managed by the GTX 560 Ti 1GB.
The GTX 460 768MB proved to be a great buy in our last folding roundup. It's certainly cost-efficient, second only to the GTS 450 1GB, but it's a long way behind the GTX 560 Ti 1GB in terms of power efficiency when folding. The latter is also noticeably faster in games and very overclockable. What's more, as most GTX 560 Ti 1GBs come equipped with third party coolers, they run at similar temperatures to the GTX 460 768MB too.