Well whats the track record from chiphell on such matters?
That's the point. If the leak was from anyone else, it would be too easier to dismiss. But ChipHell was THE only site wth 3 consecutive generational leaks that were pretty damn close: Tahiti’s preview launch numbers (7950/7970) and even the most recent Volcanic Islands R200 series and Maxwell GM204 launch turned out to be quite accurate in terms of the performance numbers. Actually the GM204 leaks were underclocked engineering samples and the final cards performed even better than the leaks from ChipHell.
I think people fell for the GM 204 hype. While Maxwell is undoubtedly an awesome architecture from a perf/watt point of view, 970/980 aren't
that awesome performance wise vs. 290X at high rez gaming.
If AMD bumps performance just 30-35% over 290X, you are already 15-18% faster than the 980. NV's 970/980 look really good because of the negative stigma of reference 290/290X, and because they are new tech with newer features and less power usage. As far as performance goes, they have hardly moved the bar. NV's performance also looks much better at 1080p/1200p/1440p which are the more popular resolutions.
NV hasn't even shown off the big guns. They are just milking the mid-range GM204 until they have to release 780/780Ti successors. I think 390X would need to be 25% faster than a 980 to compete favorably against the lower SKU of GM200. There is a lot more pressure on AMD with 390 series because let's face it 970/980 are really 960/960Ti.
Performance:
380X > 980
390X = 295X2
Power consumption:
380X = 280X
390X = 290
Sounds hard to believe without 20nm + HBM + very large die -- a trifecta very unlikely this early in 20nm cycle. If true, it would sell out right away.