memory limit on 32 bit machines
One of my clients hit the 2GB limit of RAM being used on a 32 bit machine.
Is this limit per processor? That is, can running parallel on 2CPU's give access to the total of 4GB which is actually available on the machine?
It is per process; so running -t2 parallel will use all 4Gbytes on Unix/Linux.
The same for Windows.
Windows 32 bit allows up to 4GB. By default, each process can use up to 2GB. So if you have two processes running, you can use almost 2GB for each of them (the operating system will consume some memory). More than 4GB of RAM makes no sense because the operating system cannot manage more than that.
Adding the flag /3GB in the boot.ini file will allow Windows XP (not Win2k) to use 3GB per process but still the overall limit is 4GB. Furthermore, processes that use more than 2GB may not run properly.