Everyone else is struggling with node transitions since it's becoming harder and harder to shrink transistors to lower nodes. Even Intel's world's leading manufacturing facilities had some issues at 22nm. TSMC and GloFo are behind Intel.
If you followed the news here at Xbitlabs or other tech sites, AMD's relucancy to adopt most expensive/newer nodes has been discussed a year ago by the current CEO:
"Now, let's talk about 20nm and 14nm. I think that we really flying hard in the path of subatomic environments. The price advantages as we move down nodes are starting to wane. The ability to [quickly improve] yields and ramp up our products (which have fixed amount of time) is under exceptional pressure. It costs huge amounts of money. I think we have to be strategic and think about how quickly we go down the node,[...] Just go look at the cost of wafers as you move down those technologies, they are not going down, they are going up! If the yield does not go up, how do you get your return? You have to charge bigger prices."
http://www.nordichardware...odes-less-attractive.html
TSMC raises prices on AMD and Nvidia [for 28nm]
http://semiaccurate.com/2...-and-nvidia/#.UM9GSW9ZUeo
Nvidia suffers as TSMC's 28nm ramp steeper than expected
http://www.theregister.co...dia_28nm_ramp_q4_numbers/
The rising wafer costs and ramp up time to justify the move to next node process has resulted in a lot more risk than before. New fabs costs more than ever and naturally when you adopt a newer nodes, your yields are worse than existing and mature node. These added costs are then passed on to fab customers like AMD/NV, etc. Why do you think NV was unable to launch GK100/110 in the consumer space in 2012? It could never meet the volumes at existing 28nm yields and it wouldn't have been able to afford selling 500mm^2 die at 2012 28nm wafer prices at just $499. 20nm wafers will be even more expensive.