In 2008 I had 8 RV770s in an HP workstation connected to an Aprius PCIE expansion box running 64-bit Windows (2.4 TFLOPS sustained running my 1k FFT). What's the maximum number of GPUs anyone has connected to a single x86 root complex under Linux recently? Anyone had success with 16? 24? Other than physical connectivity, what's the theoretical max and what's the limiting factor?