SLI (or CF) does not scale memory capacity meaning that VRAM does not add up, unlike memory bandwidth which does, indeed, double. Your setup currently has 1.28GB of VRAM to play with so keep than it mind when adjusting settings in various games. For Titanfall you should stick to High textures if not Medium when using 4xMSAA which eats up additional VRAM. As for proper SLI support you can read my previous post with the official NVIDIA statement regarding Titanfall. With very good drivers/game support your system would be the rough equivalent of a Kepler part with 1728 cores at 732 MHz, 1.28GB VRAM and a memory bandwidth of 304 GB/s. When using one GPU that would be 960 cores at 732 MHz, 1.28GB VRAM and a memory bandwidth of 152 GB/s.