Come to think of it, it's not even feasible to run the motherboard's circuitry to allow DIMM slots in any random location to work with a CPU socket farther away. The physical distance the DIMMs are from the CPU is very important since light only travels 11.8 inches per nanosecond, which is the unit of measure the RAM timings are based on. A slot that's too far away will be out of time with the closer slots.