RAM usage - increases over time?

[rcf-dds]

I don't know much about RAM and how it really works but here's my question:

(i have new unibody 13" MBP w/ 4GB RAM)

When i do a fresh restart i have anywhere up to 2.5-3GB free with basically NO applications open. But as time passes, web browsing, sleep, etc the amount of free RAM available goes down to <2GB even when i exit all apps...

1. Is this typical? What's the explanation for RAM being eaten up over time? Is it advisable to do a fresh restart every couple days or so just to free up RAM again?

2. Is it even common with 4GB of RAM for half (2GB) of it to be used all the time? (I'm guessing yes, but just wondering what's the explanation) For those who only have 2GB of RAM, do they always have 1GB being used? Or would even those 2GB's always be taken up?

Thanks, sorry for the dumb q's, i dont know much about RAM but i love my new MBP!

 

[BlueRevolution]

Is this typical?

Yes.

What's the explanation for RAM being eaten up over time?

By my understanding (hopefully someone will correct me if I'm wrong), the OS allocates memory as applications are launched. They may not use all allocated memory, in which case the memory will be reallocated as new applications launch. The "free" memory is the amount of memory that has not yet been allocated.

Is it advisable to do a fresh restart every couple days or so just to free up RAM again?

No need.

Is it even common with 4GB of RAM for half (2GB) of it to be used all the time? (I'm guessing yes, but just wondering what's the explanation)

Sure, for reasons mentioned above.

For those who only have 2GB of RAM, do they always have 1GB being used? Or would even those 2GB's always be taken up?

Depends what they're doing with it.

Thanks, sorry for the dumb q's, i dont know much about RAM but i love my new MBP!

Bottom line: if it's slow, add more memory. If not, don't worry about it!

Enjoy your new computer.