They are pretty close to each other, especially overclocked lower-tier to stock higher-tier. As you say, they're priced accordingly though, so they seem to be where they should be. The 7950 costs approximately $50 more here in the US, averaging ~$350, so it's where it should be too.
Competition might drive all of them down, and hopefully soon...but pricing is surprisingly perfectly controlled by the market right now... HD 7870 slightly < GTX 660 Ti, which is slightly < HD 7950, which is slightly < GTX 670.
While 1080p FPS might be similar to the GTX 670, there is a solid difference when considering multi-monitor gaming. The reduced memory bus shows its limitations pretty strongly in that scenario.
Yes they are priced acordingly
Its all it takes really, 12.6 drivers,- a refrance 7970 = GTX 680, 7950 ~ GTX 670, GTX 660Ti = 7870 + or ~ 7950.
There are wider performance gaps and price gaps between AMD cards, going from 7970 to 7950 is a 20% hit, from a 7950 to a 7870 is another 20% hit and the prices reflect that.
What i want is to max every game at 60+ FPS @ 1920 x 1080P including BF3 and have some good overclocking fun. thats exactly what i have in the 7870 and priced well for that, while the 7950 is a significantly higher performing card that is also priced acordingly.
As for multimonitor it seems even the 2GB GTX 670 / 680 also struggles more than the 3GB 7950 / 7970 at such high res, you have to pay a premium for the 4GB vertions,
In a strange sort of way none of the normal Nvidia line seem to fit in anywhere.
it looks a lot like Nvidia had the 7870 in there sights and the way they chose to beat it was by sticking 192Bit memory on a GTX 670, so they ended up with a memory throttled GTX 670 where the memory already wasn't great.
Would it not have been better to have a 256Bit memory bus on it with less shaders?
Just to be honest, not having a dig. Had i not already had the 7870 i would have gone for it over this anyway, and i had considered waiting to see the 660TI.
I like the fact that it has a 670 Chip on it, i like it performance. at stock it is faster than my card.
But i don't like the price, for that money (UK i know) the 7950 is by a good amount the better card.
Last but not least, i don't like the idea of a 192Bit memory bus, my emagination in that (right or wrong) is texture fill throtling ecte.... Its off putting.
The 660TI is priced well, i think this will bring AMD's prices down, but that will leave Nvidia in a situation where there top end card GTX 680 vs 7970 is so much more expensive at the same performance they will have to drag there whole line down before they made much money on the mid level cards (which is the main R&D)
AMD have already had there R&D from the 78## series cards with a nice small, cheape DIE size, the 8### series is out next year again already.