Midrange Pascal is rumored to be out in May... but it, rumor, is GDDR5X not the flagship HBM2. I would GUESS it would beat a 980Ti, but, not sure.
Right.
On a purely fundamental level, think a 512-bit (GP104) vs 384-bit bus (GM200), as GDDR5X is twice the bandwidth of GDDR5. That said, GDDR5x tops out at 6ghz (12000gbps), GDDR5 at 8ghz, but 980ti also uses only 7ghz GDDR5.
Normalized, the equivalent amount of bandwidth on 980ti would be 256-bit/5.5ghz GDDR5x. GDDR5x is available at 5, 5.5, and 6ghz speeds.
IMHO, expect something that can tap out 6ghz/256-bit for the high-end of GP104, and a slightly lower spec for the 'x70' version more-so similar to 980ti (just as GM204 was to big Kepler). While not a super huge difference in that respect on paper (granted one would hope it is reflected in price), don't underestimate nvidia could replace some SFUs (essentially what makes a 980ti similar to having 3520 units versus it's actual 2816sp) for actual shader processors, similar to AMD, among other bandwidth efficiency tricks. This could improve compute, granted at the price of other gaming efficiency. That said, the high-end model will probably be a tighter configuration than what is seen on 980ti (more-so similar to Titan X), making a design more people will buy over-all more efficient, while perhaps still clocking well within it's given TDP (unlike Titan but more-so similar to 980ti).
TLDR: GP104 is almost certainly going to attack the same market as GM200; the '1440p60/4k30' high-end gaming niche, 4k60 mainstream title market...probably exactly the same thing as Vega10, and one would hope within 225w. Odds are GP100 (using 1ghz HBM2) will be configured in such a way when overclocked it can obtain closer to the 4k60 high-end ideal (similar to GM200 was with 4k30 high-end PC titles/60fps ports), and as-such will probably be closer to what the stock 1.2ghz HBM2-using Volta will achieve at stock. This would probably also sit well with Volta bringing 7 or 8gbps GDDR5x, if not lower-end HBM2 (800-1000mhz) to the performance segment (GV104) as well.
That seems the most likely progression to me, but I certainly could be wrong.
As was said, we're literally only a couple days away from the Pascal keynote at GTC, and that will likely blow everything wide open in terms of what exactly the architecture is, and hence what we should expect in terms of configurations/markets the skus are aimed.
That said, would I buy now or wait? Most certainly wait...no matter what.
Not only because of the 4k possibilities of GP104, but what seems to be overwhelming evidence Polaris will be aimed at EVERYTHING below that. While AMD may or may not achieve 1440p30 high-end/60fps ports at the upper-most levels of that chip, unless nvidia pulls another $300 970 with the low-end GP104...and perhaps even then...Polaris 10 will probably end up being a much more cost-effective, good-enough chip for many people (especially those running at 1080p). I would expect at least the perf/$ of 970, if not a better ratio.
The question in my mind really is the cross-over of high-end Polaris 10 with low-end GP104. How will each perform; what will each cost? Will one be able to obtain 4k30 and/or 1440p60 most of the time while the other won't? Will one cost $300 and the other $400...and if something along those lines is the later worth it to EVERYONE, let-alone someone whom could be content with a lesser Polaris 10?
That will be the interesting thing to watch imho, and depending on performance, could end up being where the price wars occur and many people could benefit (regardless of choice) depending on their situation.
