I thought that I understood how MacOSX manages memory, but recently I’ve become baffled by its performance. Here is the situation:
- I have a brand new Core i7 system with 8GB of physical memory running MacOSX 10.6.7. There are a few Apps running regularly taking up some of the memory—Safari, Mail, Xcode, Terminal, etc.
- I need to run three 64-bit processes in parallel, each of which uses about 2000M of real memory.
- Although the wired memory stays below 1000M (i.e. I have over 7000M available for processes), I see heavy paging activity leading to very bad performance from the three memory-intensive processes that I launched.
- Apparently, I am not running out of available RAM, as the reported inactive memory stays around 2500M and the active memory doesn’t rise above 5000M.
Can anyone give me a clue as to why MacOSX does not release the inactive memory for the processes that need it, instead resorting to paging? Also, is there any proper way to influence the memory management by the system?