Recently I saw a tour around Wilk Elektronik fab (Polish company, they own GoodRAM brand). http://www.egielda.com.pl/?str=art&id=2902&action=all (its in Polish, sadly no interesting pictures )
There was one interesting thing - their testing lab. Currently they are using modded PC motherboards (Variable Voltage Regulator) to test modules (bad chip detection, performance). At the end of the tour Lab monkey showed of his latest monster, test setup for hot swap module testing, the key point and main feature of this beast was using PCIE Video card memory for the main program memory.
Currently LinuxBios is using CAR for ram. What about using Video card memory? is that feasible? Can you setup Video memory as stack?