What I failed to add were the points made by others about how this increases cost substantially without really offering any guarenteed benefits. Think about it as an upsell proposition it's hard to as $100 or more for 'up to' 70% faster, particularly to the majority of folks buying it as an item of consumer electronics rather than as a computer. If I pay $100 more for model A over model B it had damn well better give me a guaranteed boost or else I'm going to feel cheated particularly if game X is 'only' 20% and that game is Madden or CoD. Too much cost for too little gain.
Of course until there are any official specs released I have my crow in the deep freeze, just in case
Too much cost for too little gain, I don't know. There are a lot of people that don't feel that way about their sli or crossfire setups, which is all this would essentially be.
What boost is or isn't provided will be entirely up to the individual goals for a developer's game. They need not get some boost in graphics performance that is measured in a certain percentage point number. That's entirely the wrong way to be looking at it.
It's simply a fixed amount of extra rendering muscle to compliment the main gpu in doing whatever the developer decides they want it to do. How beneficial those extra resources will be is entirely dependent on how the developer designs their game. For example, this could simply come down to nothing more than a really nice looking shadow effect at a certain quality level.
Maybe the fully optimized main gpu can't accomplish this in concert with everything else the game does visually on its own, but with the extra graphics power provided by the secondary gpu, this gets you from a more unstable frame rate with this feature in busier scenes, to a more solid 28-30fps during those same busy scenes, and perhaps you can get away with making it just a little bit busier. That's all. We aren't talking about some massive boost in overall performance, or double the frame rate.
We're simply looking at a nice and reasonable way to provide console developers some much needed hardware help in optimizing the performance of their games. A lot of times developers say they would be far better served if they spent less time simply trying to get their games to run or perform as they need it to, which would give them more time to work on other important aspects, such as gameplay. If a developer, thanks to a console style sli setup of sorts doesn't have to spend nearly as much time optimizing on the single gpu to get their game to meet their performance goals, isn't this a win for developers and games?
You could say this might make them lazy, but I don't think so. There will also be instances where they push even further until they see no worthwhile gain from the extra rendering performance provided by the secondary gpu.
It's almost like we're talking about an sli or crossfire style setups as if they are experimental tech. These things are well documented. They wouldn't be unpredictable for game developers in a closed environment.
Still, until we get more solid info on this, it probably makes no sense to really dwell on it any further.