Hi all, Recently I've encountered ram issues on several computers running various versions of Windows. This makes me wonder how exactly things as Total Memory and Available Memory (Task manager) are calculated, and how the general way of handling memory works. Let's assume I'm running Windows 7 64 bit on a fully functional system. I have a 4GB RAM installed, and my graphics card has 1GB memory. According to the system information in the NVidea configuration panel, 1.5GB of the system's ram is dedicated to the graphics card. (Question: Is there a way to change this? I find 2.5 GB rather large just for graphics processing, and seriously doubt all of it is used.) I would expect things to be like this. Total memory - Just under 5 GB. If I'm correct, the total memory includes the graphics card memory. Some 10MB is used for the bios, or system resources. Available memory - 2.5GB, since 1.5GB goes to the graphics card and the rest is usable by windows/applications. Now to reality. I'm running Vista 32 bit, with 4GB Ram installed and a graphics card with 1GB memory. An additional 1.5GB of the system's ram is dedicated to the graphics card. Since a 32 bit operating system can (by default, without tricks) address 4GB of total ram, I'd expect the following stats. Total memory - just under 4GB. This is 3GB system ram and 1GB gfx card ram. Available memory - 1.5GB. Yikes. This is since half of the 3GB is reserved for the graphics card. However. The actual stats from my Vista 32 bit installation look like this. Total memory - 3.5GB Available memory - 2.7GB System information reports 2.3 as available. (Why is this different from the task manager?) My questions: - Why does my graphics card need 2.5g dedicated ram? - Why is the total memory not 4gb, and if windows doesn't inlcude gfx memory in the count, why is it not 3gb? - Why is only 2.7 memory available? - Why is, at the same time, only 2.3 memory available? - What are the actual limitations on my system by using a 32 bit operating system. I'm not looking for advice on how to improve my memory limit or which OS to use. I just want to understand. Thanks you for reading and helping me clear up this mystery.