A fair chunk dude.
The rumour goes that AMD's first Vega card will be 8gb HBM and will be around as fast as a 1070 for gaming. Apparently it does something as fast as a Titan XP but not gaming.
It isn't the big Vega card, so a 1070 competitor would be awesome. Problem is, if it's a 1070 competitor that means Nvidia can derp it enough to make sure it does not touch a TXP under any circumstance (like the 1070 against the 1080) and leave the TXP price as it is and just price it somewhere in between.
As time goes on making Titan XPs gets cheaper. Same goes for any tech really. They refine the process, etc. But yeah, those hoping for a cheaper card capable of equalling a TXP are going to be disappointed. You will pay every last dollar for every last FPS on your screen
AMD should really have ditched the kitchen sink (Async etc) but I guess it's too late now. It will be another gen or two before they actually show fruit from that. Same goes for HBM. It's uber expensive and if you fail on it you lose an entire die. They are going to pass that end cost onto the user (us) which is stupid because right now it does absolutely bugger all for gaming at less than 4k and the only 4k card that's actually powerful enough at the core is the XP and it uses GDDR5X, on paper nowhere near as good as HBM but Nvidia have the horses.
And that is what counts for PC games right now, horses. Give it a few years until the devs settle in with the new consoles, Vulkan and DX12? yeah, it will deffo show fruit but not yet.
AMD bolting HBM to a card and saying it's because of 4k but not having the balls to actually use it. Kinda like last time "Oh here is velly spenny HBM but f*** you you're only getting 4gb of it !"
I think their CPU lineup is the polar opposite of their GPU lineup.