Shared memory means less for OS

An In.Tech reader inquired recently:

I bought a computer recently with the following specifications:
Processor: AMD Sempron 3000+ 64-bit
Motherboard: A33G SATA ATX
Memory: 512MB

However, when I did a system information check, I noticed that the memory showed this information:
Total physical memory: 447.30MB
Available physical memory: 212.26MB

Have I been short-changed?

A. Samy
via e-mail

It sounds like you have a motherboard with integrated graphics, or as it is sometimes called, built-in graphics.
The A33G motherboard is from PCChips and the website specifications indicate “Embedded Mirage Graphics with 128MB shared memory”, which is also another way of saying integrated graphics.
As the phrase suggests, the graphics system is sharing part of your main memory, which results in decreased memory for the operating system and other programs. In your case, about 64MB is being used by the graphics system.
If you’re concerned about memory usage, you can reduce the amount used for graphics via the BIOS settings, which are accessible during startup. If you’re not playing games on your PC, you can get by with just 32MB or even 16MB for the graphics.
However, the better alternative is to just buy more RAM. These days, RAM prices are quite reasonable. Your mobo is listed as using DDR2 RAM; if you’re buying new RAM, make sure it matches the speed of your existing RAM.