Since I got asked about it here's some updates on what I think is going to happen regarding the new GPUs.
I can't give you any exact performance numbers, since that depends on clock speeds (which might be tweaked to make the performance fit the segment they're going for) and the actual number of execution units, which I can only guess at this point. I definitely won't talk about how the salvage chips stack up to each (e.g. will the cut down version of "big Polaris" beat the cut down version of "mid Pascal") since that depends on those and on top of that also how many cut down versions there will be (2 or 3?) and how far cut down they are (which again might be decided by market placement, rather than technical reasons).
So here's what I think is most likely (no guarantee that it'll actually happen exactly like that):
AMD (code names are a mess):
"small Polaris"/Polaris 11/Baffin: Performance around 370 / 380 (AMD) or 950 / 760 / 960 (nVidia), 3-4GB GDDR5, vastly more efficient but not all that interesting on desktop. Important for AMD since they need efficient "low end" GPUs for mobile where they've been losing ground to nVidia. This is the one AMD demoed back in January, so it should definitely be ready for computex, launching it sooner doesn't make much sense. Availability might be bad since most of them will be going into mobile, unless you care about power consumption immensely AMD already got a very strong lineup in that performance segment.
"big Polaris"/former "mid" Polaris/Polaris 10/Ellesmere: Performance around 390X / 980, 4-8GB most likely GDDR5, again vastly more efficient, we're talking just above 100W. These are the cards that I think will be the most interesting. Think 390 except with better performance and half the power draw. Since there's no HBM and it's a fairly small chip compared to the old high end chips we could see some pretty good prices here. I'm expecting it to be ready slightly after small Polaris so they're probably trying to have it in time for Computex as well. If they have to delay it for some reason or want GDDR5X at all cost we might only see it later in Q3, in that case GDDR5X seems possible/likely. They'd probably do a "on paper launch" at Computex with working GPUs, but not have enough volume to ship them until late Q3.
Vega/"small Vega"/former "big Polaris"/Vega 10/Greenland: Performance around 20-30% faster than Fury X / 980 Ti, 8GB HBM2, same deal with the efficiency (>Titan X performance at 980 power draw (<200W)). Probably around Q4 2016 at best, Q1 2017 seems most likely. This is mostly because of HBM2 availability, since they probably won't want to run out of stock like with the Fury.
After that we'll most likely see "big Vega"/Vega 11/ maybe Vega 20 (fuck these code names) sometime around Q2 2017, significantly faster than the Fury X / 980 Ti, ballpark figure would be +70%, probably 16GB HBM2, but this is all pure speculation. At that point it's a matter of how far you want to go since bigger chip size does have a significant negative impact. Going bigger doesn't only affect those GPUs, it also means your next GPUs with a possibly more area efficient architecture need to be bigger to be faster by large enough of a margin to sell well. So you want to hold back as much as possible without giving up market share/sales/profit to the competition or even just due to people not buying and waiting for the next gen. On 14/16nm neither AMD nor nVidia can or want to go balls to the wall with 600mm² chips for the sake of the performance crown in the consumer segment since it wouldn't be profitable. Both will put a lot of thought into how big their new high end chips will be so I really can't predict that yet.
Now nVidia:
GP107/"very small/entry level Pascal": Very similar to small Polaris/Polaris 11, maybe slightly slower. Will probably appear in Q1 2017 so not worth talking about yet.
GP106/"small Pascal": Performance around the 380X / 970, so between small (11) and big (10) Polaris, probably 4GB GDDR5X, launching probably Q4 2016.
GP104/"mid Pascal": Performance slightly faster than Fury X / 980 Ti and therefore somewhere between big Polaris and small Vega, 8GB GDDR5X, possibly GDDR5. Now this is where it gets complicated. I'm fairly certain that this is the chip that nVidia was just about to get in January, which means that it won't be ready for computex. There's also the fact that quite a few people are fairly certain that it will use GDDR5X which they won't get enough volume until then either. On the other hand they probably don't want to let AMD just grab the juicy 300-500$ market, so a paper launch at computex, which will indeed look impressive on paper since it should beat big Polaris significantly, seems likely. At the same time I'm not all that fussed about it since it will beat the Titan X. That's right, performance is a downside here. They don't want to massively devalue all of their cards so they actually have to charge a massive premium for them. Not that nVidia will mind that or wouldn't have done so anyway. Since they still have to compete somehow we could see some very nice price drops on the 980 and 970 though. Again nVidia won't mind since they got terrific yields on those. In light of the DX12 issues of Maxwell, possibly another round of driver induced performance gimping and the fact that you really don't want a monopoly that probably won't change my recommendation. Unless AMD fucks up "big Polaris" is where it's at.
GP102/"big Pascal": see "big Vega", about 70% (plus minus 20%, it's that uncertain) faster than Fury X / 980 Ti, 16GB HBM2, Q2 2017, pure speculation.
tl;dr
Releases:
Computex (June):
Polaris 11
Polaris 10
GP104 (on paper)
Q3:
GP104 (actual availability)
Q4:
GP106
possibly Vega 10 (on paper)
early Q1 2017:
Vega 10 (actual launch)
sometime Q1 2017:
Gp107
Q2 or later 2017:
Vega 11 or 20, whatever they'll call it.
GP102
Performance of the full chip, cut down versions will be lower* (lowest to highest):
GP107
for reference 380 / 960 are about here
Polaris 11
GP106
for reference 390 / 970 are about here
Polaris 10
for reference 390X / 980 are about here
for reference Fury X / 980 Ti are about here
GP104
Vega 10
GP102
Vega 11
*There will be overlap, e.g. cut down Polaris 11 between cut down GP107 and full GP107 seems likely
still tl;dr
Computex (June) 2016: POLARIS 10 GET HYPE