Which GPU renders faster in cycles GTX 980 or 780Ti?

I was wondering which GPU is faster at rendering in Cycles the 4GB GTX 980 or the 3GB GTX 780Ti I read on nvidia’s website that the GTX 780Ti has 2880 cuda cores versus the GTX 980’s 2048 cuda cores. I know that the 980 is newer technology and has more memory than the 780Ti but is the 780Ti faster at rendering in Cycles because it has more cuda cores?

Can anyone help me out with this question I need to know before I buy either one of these cards?




Since they are results from different dates, there may be small differences in render time. Anyway, I always prefer new technology and more vRAM. Between those two I would choose GTX 980.