von neumann architecture fix

Everyone knows about the von neumann architecture and the bottle necks that come with it.  I have an idea though.

Why not have two separate sets of ram, one for memory and one for programs?  Both would be exactly the same, both able to read/write/store code like normal ram, but while one ram is executing it can use the other one for memory storage eliminating the bottle neck.  Also all programs would be backwards compatible because a program can still run on a single side of ram and leave the other alone.

Would this be an easy solution or am I missing something here.

>>9 Self-modifying code would be possible if you allocate the 2xtimes of memory to the application and let it store itself into the another part of the memory after completing its normal sycle then run the new stored code structure and erase the old. It might end up beaing the program where in the end there will be a retarded program which cant complete its original reason for exsinstance but still i would love to try it one day when im bored from reading SICP and watching chamichingas.