AMD wont be so stupid as to name a dual-GPU card as a mainstream lineup option. I know a lot of people dont have faith in their marketing skills, and there's a bit of merit to that, but this would be a step too far.If a 490 does release in December it wouldn't surprise me if it was a dual Polaris chip and they market it as being specifically for VR. Then it would be priced so that it looks like a bargain compared to the Radeon Pro and don't forget AMD "wouldn't suggest you buy it for every day gaming" but many would buy it just to regret it.
It depends how forward thinking the Radeon group is, It may make them a few bucks in the short term but it would once again damage the brand name by focusing on mgpu which has a negative effect on the brand due to how unreliable it is.
Think about it, A few short months back loads of people were claiming DX12 was going to turn things around for mgpu yet it has had the opposite effect so far, It may eventually improve things but it's going to take years for that to become the case so for now another mgpu card will not do AMD any favours..
The time for doing such a thing has passed anyways unless Vega is like 8+ months away or something, which I doubt.
For one, how is this 'no secret'? I'd say it's *very* secret. Seems the only evidence we have of it is some Youtube ranter with some incredibly outlandish ideas. That seems to be what most people who say this base that off of. Other than that, there's been absolutely no solid rumors or suggestions this will happen.Pretty sure if there is a 490 in December it will be dual Polaris 10 chips on an interposer or similar structure. No secret that this is what AMD have intended to do for ages. Multi GPU but without the driver / engine headaches.
But I doubt we'll see anything before January, and this would be sooner than anyone expected the multiGPU, but singleGPU as far as the OS is concerned, product. Refreshed VEGA, NAVI or XB+ were the expected debut.
I know you're going to talk about how stacked memory is some indicator this is where GPU's are going, but GPU's are not memory chips. It's a whole new world of complication doing what you're suggesting. And it would *not* suddenly solve any multi-GPU issues whatsoever. It would probably create its own set of unique challenges/headaches on top of many existing multi-GPU issues.
I'm still betting hard that 490 is going to be baby Vega and that we'll see a new 'named' top line chip for the top Vega GPU. Dont know if it'll be called Fury or whatever, but something outside the numbering scheme. I think strong evidence for this is that we've seen an official AMD slide where they planned to refresh Polaris with a revision '475/485/etc', meaning the 400 series will stick around for a bit.