Well, at least I have a nice juicy rumor just in time for the weekend. Asian based Benchlife claims that Nvidia will release a Pascal architecture based GeForce GTX 1080 with 8GB gddr5x in May. It would make sense as HBM2 will be available in volume only later in the year.
There's a precise date being mentioned as well, May 27th, four days prior to the Computex exhibition. Obviously Nvidia is not going to comment on this rumor.
The GP104 based GTX 1080 would get a 256-bit memory controller tied to 8GB of gddr5x memory. The usage of gddr5x over regular gddr5 is rather speculative as it isn't even in volume production that we know of? Micron (the only one that will fab these gddr5x ICs) announced in a recent blog post that they intend to commence high-volume production of GDDR5X chips in mid-2016, or sometime in the summer. But who knows, Nvidia have gotten their hands on an early batch for a couple of thousand cards right ? GDDR5X is your standard GDDR5 memory however, opposed to delivering 32 byte/access to the memory cells, this is doubled up towards 64 byte/access. And that in theory could double up graphics card memory bandwidth.
Early indications according to a presentation show numbers with the memory capable of doing up-to 10 to 12 Gbps, and in the future 16 Gbps. So your high-end graphics cards these days hover at say 400 GB/s. With GDDR5X that could increase to 800~1000 GB/sec and thus these are very significant improvements, actually they are competitive enough with HBM.
Pascal GPUs are fabbed in the Taiwan Semiconductor Manufacturing Company (TSMC) (recently hit by an earthquake) based on the new 16nm FinFET process. 16nm should result in significant power savings. The card would only need one 8-pin connector for power needs. The card would get a DVI, HDMI and two display ports. From the looks of things, and as expected .. this is not 'Big Pascal' GP100. That GPU would get 17 billion transistors made on the 16 nm FinFET+ node at TSMC and likely the HBM2 memory.
So to recap, in the latest prognosis Nvidia are rumored to launch the first high-end GP104 GPUs with models GTX 1080 and GTX 1070 (should Nvidia use this naming scheme). These chips would come in a 37.5×37.5mm BGA package, and get 2152 pins.
Rumor: GeForce GTX 1080 8GB gddr5x based on Pascal GPU in May
