where's the bottle neck in production? is it the lack of GDDR chips globally? that was the vega's problem.
There are multiple issues.
RAM has been in short supply for most of the past year - which is supposedly why the pricing on it has at least DOUBLED over the course of 2017 and is why a lot of MSRP prices have drifted up especially on higher-end cards.
This appears to be a limit of the lines the RAM makers are making RAM on - at least 2 of them have announced they're building new lines (but that appears to have been more about "moving up from 22nm" at the time vs "need more capacity than our existing lines have).
TSMC has been running flat-out since they fixed their issues after the earthquake damaged their "current node" lines a couple years ballpark back.
GF is so overloaded AMD has had to find foundry space ELSEWHERE for some of their production (as reported in one of their recent earnings reports in an indirect way, in the description of a charge they had to take against their most recent modification of their agreement with GF) - I'm guessing Samsung as they seem to be the ONLY "available" foundry on the 14/16nm node to have any capacity to spare (I don't think it's likely Intel would share THEIR foundry space with AMD at any price).
It says something positive about AMD "looking forward" that they DID negotiate an option with GF to take some of their business elsewhere if GF couldn't handle all of it.
The PRIMARY issue on the NVidia side right now though appears to be the "end of year" switchover in production (as reported and confirmed in late October by TSMC) from Polaris GPUs to Volta GPUs, coupled with a VERY GOOD Christmas sales season cleaning out existing stock and "in the pipeline" supplies of Pascal cards 1060 and above (the 1050 and 1050 ti are Samsung made, newer designs, and appear like they will be in production for a while longer as Nvidia introduces the HIGH END Volta cards first like they did with Pascal).
On the AMD side, there does appear to be some push from Ethereum miners - but nothing anywhere near as big as back in the spring when it's price jumped about 30x in less than 2 months, I suspect the primary issue there is ALSO a very good Chrismas sales season (likely with SOME carryover from Nvidia being short on cards since AMD cards were still in widespread stock more than a WEEK after Nvidia supplies evaporated) coupled with AMDs deliberate AND ANNOUNCED refusal to meet ALL current demand so they don't get hammered later on by the massive "used card dump" they expect when the current Cryptocoin GPU mining "bubble" pops.
While it's not certain at this point that cryptocin PRICES are in a "bubble", the mining side WILL take a major hit on profitability when Ethereum moves to full Proof of Stake and well over half the GPUs currently used in mining suddenly have to find new homes 'cause the Ethereum they WERE mining is no longer mineable at all.
THAT collapse AMD (and to a much lesser extend Nvidia) can COUNT on happening, unless cryptocoin prices start exploding AGAIN shortly before or as that Proof of Stake move happens.