We are planning to build a pair of multi-GPU Linux servers for machine learning and data science tasks. Per our requirements, we need to put a lot of RAM in these machines; we're planning on 24x 64GiB LRDIMMs for a total of 1.5TiB. For GPUs, we were going to use Titan X's for the best bang for the buck, but according to Nvidia's Linux driver documentation, current-gen cards can't handle more than 1TiB of host system RAM. I've heard "rumours" that the Pascal architecture will come with increased addressing capabilities, but I can't find any reliable documentation to confirm or contradict this. If this turns out to be true, we might go with the newer GTX 1080 cards, even though they have 4GiB less RAM on the graphics card.
Hence my question: is there some documentation of Pascal's addressing capabilities that I'm missing?
Or alternatively, could somebody with access to a GTX 1080 run a
grep DMA /proc/driver/nvidia/gpus/domain:bus:device.function/information
for me?