32/64bit computing

What Does Mean 64bit?

- 64bit addressing
   - The program has 64bit address space for memory access
   - So it can access more than 4GB of memory per process
   - This requires OS and H/W which can manipulate 64bit memory address space

- 64bit precision
   - The variables are 64bit and go through the computation with 64bit precision
   - This requires more memory than 32bit precision
   - This may require more disk space for input/output data
   - This requires more computational power than 32bit precision