FWIW I only get 12GB/sec pver PCIe with NVIDIA's BandwidthTest tool. Versus the 512MB segment, which comes close to that 28GB/sec number, it's a pretty big difference even before taking latency into account.Reading from last 512mb vram in gtx970 is 22GB/s, and pci express 3 is 16GB/s so no big difference, but to read from system ram we have to copy it to vram(16GB/s) and then read from vram, thats the difference ?