It depends :-) over the years I have switched between the 2. In the early days I was more pro amd (ATI) and the most recent years I am edging more towards Nvidia.
The one that you can get. With all this mining stuff many gpus are unavailable. Also nvidia is not so good for free software because it is encripted for some reason. Not an expert here but amd is better in my opinion. I am saying that as someone who has nvidia.
Then if you want performance it is all about specific card and optimisation.
It depends :-) over the years I have switched between the 2. In the early days I was more pro amd (ATI) and the most recent years I am edging more towards Nvidia.
However it depends greatly on:
I always start out watching benchmark sites or review sites. A good place to start would be: http://www.tomshardware.com/reviews/best-gpus,4380.html
The one that you can get. With all this mining stuff many gpus are unavailable. Also nvidia is not so good for free software because it is encripted for some reason. Not an expert here but amd is better in my opinion. I am saying that as someone who has nvidia.
Then if you want performance it is all about specific card and optimisation.