What's taking my active memory?

[gatortpk]

I have searched around for another thread to address this, but I couldn't find any.
I have attached an image of the Activity Monitor, (yes, I covered my name with "User", but the rest of the shot is genuine. As you can see to list is sorted by process memory allocation, and it doesn't add up! I did get 16GB of memory to avoid any Swap Memory! I'm shocked, and well I can't tell any performance hits at all even running 8 processes at 90%+, but still! Can anyone explain this?

I am running the 64-bit kernel as you can see, and I am running Sophos to clean out a Windows NTFS partition. (Yes all the other processes below what can be seen have a much smaller memory footprint per the sorting). I'm running an iMac (again with 16GB of RAM), Late 2009 Quad Core i7, that's also obvious (again) from the image since I'm running 8 processes above 90%. Are there processes that are hidden from Activity Monitor? "Top" says about 3100MB are active, makes more sense, but it also reports 16GB in use, 12GB inactive and 25MB free. Again, can anyone explain this?

Thanks in advance!

 

[gatortpk]

Top (app in Terminal)

Top is pretty awesome, it will show 26 columns of data when the window is at least 1700 pixels wide. When I extend it to 4400 pixels (with two monitors), it's still 26 columns of data. I just wish I could sort those columns like I can in "Activity Monitor". Again, does anyone know why "Activity Monitor" shows 9+GB of Active memory while Top was showing 3GB?

By the way, they are now agreeing to around 6.2GB of Active Memory, just minutes later. (Though I haven't done anything new and Top was reporting about 3GB of active memory a few minutes ago, instead of 6.2GB now?) Any answers why Activity Monitor was wrong a few minutes ago, and anyone know how (or if one can) to sort the columns in "Top"?

Also, anyone know how to get the Inactive memory to decrease and "swallow" the 1.43GB of Swap used? (Besides restarting)

 

[Isair]

I would use vm_stat instead of top to see memory usage. If Apple ever gets done with reviewing, there is this: http://www.barissencan.com/products/iMemoryCleaner/ which'll be in the App Store for $0.99. Just to let you know inactive memory is used as free memory when needed, so decreasing it and increasing free memory theoretically shouldn't decrease your swap usage. The OS should, when free memory is not available, give some space from inactive memory to the application that needs more physical memory space.