Artanoon, all! Right, before people go jumping in with sarcastic comments, I do know there is a marked difference between the GPUs in my question (to follow) but I'd like to understand why/where it is as I'm not fully clued-up on the techy side. So, to the question then. I've got a pair of 670s in SLI and I was looking to see what my next sensible upgrade would be (more out of interest, since I'm not using them at full potential right now anyway). I went on Wikipedia to get the specs and release dates for different models just to see what the differences were and I got a bit confused. An original Titan for example, is listed as having: 14 SMXs 837 MHz Base clock 40.2 GP/s pixel fill rate 288.4 GB/s memory bandwidth 4499.7 GFLOPS and the GTX670 has: 7 SMs 915 MHz Base clock 29.3 GP/s 192 GB/s memory 2459.52 GFLOPS Now, I know the Titan whups the 670, but why does it still beat two in SLI (assuming it does)? What is it that stops SLI just doubling the 670 stats? There must be a bottleneck somewhere, otherwise nobody would buy Titans for example, but I'd like to know where. Grateful for any educational assistance!