|The 4gb virtual memory address limit for 32 bit operating systems.|
An example of 3gb working better than 4gb in a 32 bit operating system.
See Response 6:
A better explanation I've seen.
If you have a 32 bit operating system and you have installed 4gb (or more) in the mboard, the amount of that ram available to Windows and the user is
4gb minus the amount of ram your devices require or have.
- minus the amount of ram shared with onboard video if you're using that
- and/or - minus the amount of ram your dedicated video card installed in a slot has.
If you have more than one video card installed in a slot,it would be minus the ram for all of them.
(and = Some mboard main chipsets have Hybrid video capability. If you have a PCI-E X16 video card installed in a mboard slot that is supported by that feature, it's often the default for both the onboard video and the video on the card to work at the same time, unless you change default bios Setup settings. In that case it would be minus the ram for both of them.)
- minus the amount of ram your sound adapter has, if that applies - e.g. sound cards installed in a mboard slot often have ram
- minus the amount of ram any other devices have, other than hard drives and optical drives, if that applies.