With the official NDA date set for the 22nd of October, we're starting to see some officially-unofficial postings on forums with benchmark numbers that look like the real thing.
We're not sure whether these benchmarks are included in the AMD 6800 press deck or if they are "independent" benchmark attempts. The first glaring fact, according to these numbers, is that the HD 6870 and HD 6850 will underperform the GTX 480 by a relatively wide margin, as you can see here.
Not used to being second... There might be good reason for it, tho'
So, if we treat these numbers as feasible, the Radeon HD 6870 and HD 6850 both underperform the GTX 480, yet outgun the GTX 460 in both its incarnations. The HD 6870 will lose by almost 10 per cent to its predecessor the 5870, if you think strictly of naming and segmentation.
Compared performance: Radeon HD 6800-series vs. the rest
You can draw one of two conclusions from this: AMD didn't actually squeeze any extra performance from the new chips and in fact lost something in the process, or; AMD is reshuffling the chip naming scheme.
There's almost no doubt it is the latter, as there is no reason for performance to actually go down from one generation to another. So in this scenario, this is how it plays out: Where AMD would usually introduce a top-performing chip, it is introducing a mildly-performing mainstream chip based on Barts XT (now HD 6870) and Barts Pro (now HD 6850). If AMD does indeed later introduce a higher-performing single-chip part (Cayman, for example), then it will bear a different number sequence, or ending (6890 or 6970), while the dual-GPU Antilles should bring back the '-X2' suffix to the AMD line-up.
These benchmarks give further substance to rumours that AMD would be changing its scheme a bit and would actually have no direct successor to the 5770 other than the 5770 itself.
Now if, in fact, AMD is renaming said SKUs to match a higher-rated family, then we should be comparing generation-on-generation of 6850 vs. 5750 and 6870 vs. 5770, where AMD shows a massive increase in performance (see below). If indeed this is the case, we're talking 63 per cent gains from 5750 to 6850 and 46.68 per cent gains from 5770 to 6870.
We'll know soon enough.
The only problem for AMD will, of course, be how this works out in retail and how the competition will coach its partners. Let's face it, either way you look at it, the performance in these cards - which seem to follow a clearly defined evolution path from 5870 and 5850 - will be interpreted by many as a bit of a downgrade. Imagine you have to explain to your would-be in-store customer that the 6870 actually underperforms the 5870.
AMD will have to invest a bit into their marketing to get this plan on track, as there is no easy way around the "dumbed-down" retail spiel.