I'm sorry I would also disagree about the HD6870 going backwards from the HD5870. I owned at one time 2x HD5870's and 2x HD6870's and 2 x HD6950's while I will say that the HD 6900 series was a bit of a disappointment..... the HD6870's were not. The HD 6870 was not only just as powerful as the HD 5870 IMO it was also more efficient. I also could beat the HD 5870 in a lot of benchmarks (especially when the drivers became mature.) However..... I would still consider it more of a side ways move then a full upgrade. But that would really depend on what you consider an upgrade..... Power?, Performance?, or Thermals?
The HD 6850 though I will agree was not a upgrade from the HD5850 or HD5870. While that card could overclock like a bat out of hell....and achieve almost on par with the HD 6870 it was not an upgrade from the previous gen.
Im just going by what the benchmarks where like when the card was released and it showed that the 6870 was indeed slower then the 5870 (in most games) but not by much, very little to be honest. I think you might find the reason why your 6870's beat the 5870's was well crossfire, the 6 series improved crossfire alot over the 5 series this i think is why your 6870's beat the 5870's? That would be my guess anyway.
Actually, after the naming change the 6870 was primarily intended to replace the 5770, not the 5870. The 6870's performance is somewhere between the 5850 and 5870 at stock speeds, but it isn't what it was targeted to replace. I'm not sure where you get your information from, but you might want to double check your sources.
The naming shift worked like this and there actually were vast improvements over 5xxx series, including shader speed and efficiency, faster memory, and better crossfire scaling and honestly going from the 6000-series to 7000-series did the same kind of improvements, but didn't have the same amount of improvement.
5750 -> 6850
5770 -> 6870
5850 -> 6950
5870 -> 6970
Yea but who realy believed that? honestly, primarily intended doesnt mean it did, the whole naming scheme (for me) was a bit of a joke and for most of us users made it very confusing. For "us" computer savy people we get it and understand, but for the majority it was a wtf? Why bother changing the naming scheme when in fact it doesnt make any sense at all, they should never of changed it IMO.
Anyway i get what you mean and i understand that, but in my eyes if you name a card thats the same name as the previous gen and add a 6 to the start of it, you would "expect" an improvement??
I think we sorta got off track here, my point been from the start is that none of us know how much the 8 series card will be over this Gen card (his 7970) in performance and this is why i said it is future proof and that the 5 to 6 series wasn't much of a jump compared to the 6 to 7 series, am i wrong? and does anyone one got any proof that the 8 series will be just as big of a jump in performance over the 7 series? please post away.