[quote author=“jso902”]depends on how much multitasking you do
No, not only multitasking. on modern operating systems (that is, those of the past ten years, at least), there’s always never such a thing as “free memory”.
Any free memory is used for buffering, caching… if applications need to allocate more memory, some disk cache or something similar is taken away and the memory gets allocated to the application.
This also means that more memory will almost always mean more performance. Why? Because the unused space is used thoroughly as a disk cache and after just some time of working with the machine, almost anything relevant is already in the disk cache, so that the hard drive get accessed seldomly.
Note, however, that the more memory you add, the lesser the difference you’ll notice. After 2GB or so you most certainly don’t notice very much anymore of this aspect. After a certain amount of memory, you simply have everything you need in memory.
Depending on the operating system and its configuration, after around 3GB another problem starts. The amount of virtual memory space that can be addressed linearly is only 32bits on PCs (except for the newer Opterons, which are basically a new generation). Often you can’t use the additional memory for anything else than application memory. I don’t know if Windows can handle more than 3GB at all. (the 1GB missing from the 4GB that the 32bit virtual address space addresses are kernel space, BTW)
