With visible rising numbers of leaks appeared on the internet, rumor suggests that NVIDIA is set to launch its GeForce GTX 1060 on July 7th, 2016 to compete with AMD’s Radeon RX 480 and there are reviewers who already got their hands on the GTX 1060. 
Other leaks also suggest that the GeForce GTX 1060 will come available in 3GB and 6GB memory variant just like how AMD releases its Radeon RX 480 with 4GB and 8GB memory, except for its code name which will be different for both 3GB and 6GB variant. The following table from wccftech.com is what appears to be a more detailed specification of the GeForce GTX 1060:
While wccftech.com reported that the GeForce GTX 1060 with 3GB memory will not come with SLI support in order to not messing up the sales of both higher-end GeForce GTX 1070 and GeForce GTX 1080, the alleged specifications show that we could be expecting 50% performance of the GeForce GTX 1080 based on the numbers of CUDA Cores and the seemingly near Base Clock and Boost Clock.