I lately compared the cpu time between Xenon and AMD64 in running MM5 codes (compiled on PGI 5.2), and found that the speed up was merely 1.4 times. Although the Xenon chip has a clock rate 2.8GHz faster than the AMD64 at 1.8GHz, I would expect the benefit of using 64 bits will still triumph a faster 32bit chips by a large margin.
I wonder if there’s any problem with my optimization setting or the environment? I am using the configure.user file provided in the “tips and resource” for compiling the AMD64/MM5 on Federa Linux. Do I need to use other Linux favor such as SuSE?
Any input will be greatly appreciated!
PS I also have other problems with compiling other modules of MM5 on AMD64/PGI fortran. May post my questions later …