I've had four CPUs in the same board too, but for a slightly different reason. I started with an E4300 as my core 2 upgrade from the X2 4200+. (A no better CPU, but the X2 wouldn't even clock beyond 2.2 to 2.4, the E4300 I got from 1.8 to 3.15). A few months after, my (dreadful) P5N-E bit the dust, and I bought a P35C-DS3R to replace it. That was fine, but I wanted a dual graphics board, so bought the X38-DS4 in question. The X38-DS4 saw that CPU, a short lived Q6600 before I found a good deal on a Q9550 E0 stepping on ebay. That was used for a while, then when I wanted quad crossfire (the X38 board couldn't handle 4 GPUs very well) It was upgraded to a short-lived Maximus II formula (note the trend here), promptly replaced with an X48-DS4. The X38 board, however, was reused in a system with an E5200 so I could have a fanless system.