32-bit Excel (2013) on 64-bit Windows 7 -- Limitations?

[bs0d]

32 bit Excel 2013 installed on a Windows 7 64-bit machine. What are the limitations? It seems my macro's do not execute as fast. If I understand correctly, with 64 bit Excel can use 4 processors for performance, while 32 bit is limited to 2?? Anyone more knowledgable about this let me know if its worth getting 64 instead of 32.