Re: Windows Vista, not quite alt
It is a bit more complicated than that :-(
The 4 gig maximum installed memory is due to the biggest number expressible in 32 bits being about 4 billion (actually 4294967296 ). As each memory element must be accessed using a unique number there can only be 4 billion address elements (known as the address space). Unfortunately this address space is shared with your graphics card and other peripherals. To be safe Windows (XP and Vista) actually limits applications to access 2 gig each, the remainder reserved for those peripherals and Windows itself. Some applications (I am pretty sure Photoshop is one of them) can be made to access up to 3 gig but only if you fiddle with system files to use the so-called 3gb switch. Google it if you are interested. Be warned that this may conflict with badly behaved installed hardware which expects to have that space to itself. Suck it and see.
All this does not mean that all the extra RAM above 2 gig is wasted. If you have more than one application running their combined memory allocation may be above 2 gig but limited to a max of 2 gig per application. The total can never be the full 4 gig however as the aforementioned graphics cards etc still need their piece of the pie.
Hope that is slightly clearer than mud.
Robert Hall wrote:
Can Vista use all 4 gig?