New request by popular demand: Apparently, "About This Mac" doesn't actually tell us how much RAM is being used by and made available to the system. One more screenshot, please: The following part of Activity Monitor (at the bottom)
If OS X can indeed use the additional RAM, this will show it (so I'm told).
Command+Shift+4, please. You can put to rest a lot of debates.![]()
"Snow Leopard is ready to support up to 16 terabytes of RAM — about 500 times more than today’s Mac computers can accommodate." via the horse's mouth