Thank you, John. I am well aware of that as a long term user of Premiere. As I said in my post I am interested in a 4GB version of the GTX 970.
The response above does not answer my concern that due to the Maxwell architecture of the 9 series cards, an old version of Premiere such as CS6 may not function correctly as it does not recognise the newer architecture.
Despite this post now being listed as "Answered" (not by me), I would still like the confirmation from someone who has been there and done that, that the GTX970 will function fully with Premiere CS6.
I don't know what is going on here - my response is also listed as a correct answer. I did not do anything to cause that. My post is certainly not an answer to my problem.
I am now concerned about posts which do not provide an answer to my original question being listed as "Correct" deterring those who are able to answer my question from responding.
I can confirm it works just fine. I have a msi gtx 970 and it works well it helps me to view my timeline in real time and not so much prerendering when I have effects on my timeline that supports gpu acceleration. I have old projects that I still play around in with cs6 and plugins that only work in cs6 so thats how I know for sure. It only assist in rendering when you have gpu accelerated effects and transitions on the time line and I guess during the rendering and it starts to process the parts where they are located you'll see it kick it but for the most part gpu utilization stays at 0% otherwise.
Thank you very much! That is just what I wanted to hear.
I am using a GTX680 at the moment, but with some of the recent NVidia drivers I have had problems - notably 358.91 and the one before that. 364.51 seems OK at the moment, but I have not had it installed for very long.
This sort of thing is always going to be a problem as CS6 becomes longer in the tooth.
Edit: My attempt at marking Relly Rale's answer as correct appears to have corrected some of the spurious correct markings for the other posts, but has not marked that response as correct? I do not regard John T Smiths answer as correct, and I have not marked it as such.