I am currently evaluating on an Opteron 4 processor system.
With a large code written for one processor, the gcc compiler running a particular problem utilizes about 4GB memory. When compiling with pgcc the same application and data, the program uses nearly 20GB. We have set-up memory for node-interleave. The large overhead occurs whether compiling with just -g or various faster optimizations.
Is this overhead typical and will it remain (the system has 32 GB of memory).