What is the difference between wired and active memory

These happen in real time and in a very short amount of time. You could free it up if you needed to by closing some of the apps you have running.

Once again going back to the bank account analogy, wired memory can be compared to the required minimum bank deposit you have to keep in the bank to keep your account open. If you have a machine that has a lot of RAM, you might see a lot more inactive memory because it gets harder to fill all of it. If you have very little inactive memory, then you might need to consider a RAM upgrade in the near future.

Active memory is what is currently in use by running applications. Inactive memory is memory that has recently been used by an application that is no longer running. OSX keeps track of what this is and what it belonged to because of the idea of temporal locality , the idea being that if you opened an application you are somewhat likely to do so again and if the memory is still labeled, the application can start very quickly.

In the absence of sufficient free memory, inactive memory will be reclaimed by another running application that needs memory. Free memory is just that, free. As you can see from my screen-shot image above, I tend to run with around Mb free, between and Mb wired, and the rest split between active and inactive.

What does this memory labeling have to do with how fast or slow the machine runs? When you log in, OSX claims the memory it needs to do all of its chores. This is wired. Other applications claim a smallish chunk of active memory as they are opened.

Most applications that need to keep track of any kind of history or user data gradually use up more memory the longer they are open. Some of the information that was stored in active memory by this application will be moved to inactive memory. This way, when you open iPhoto next time it will load up faster than before. Because the computer is not reading everything from its slow hard drive again.

I just ran a quick test myself to illustrate this point: After a system restart, I opened iPhoto and it took 3 Dock icon bounces to launch. I quit iPhoto, did some other stuff, and came back to it a few minutes later. This time it launched in 1 bounce. Page ins The amount of information moved from the hard drive to RAM since the last system startup.

Every time you open an application or file, this number goes up. Page outs The amount of information moved from RAM to the hard drive since the last system startup. When RAM is running low or needs to be shuffled around to the hard drive to accommodate higher priority data, this number increases. Most people look at the number next to free memory and think a low amount means they need more RAM.

And this is almost always a good thing, since it can increase speed and responsiveness. So low free memory is something to be happy about!

Instead, you should be concerned when free AND inactive memory are both very low on a regular basis. Along the same lines, an even bigger indicator of a need for more RAM is if page outs are swelling up too.

Like what you see? Subscribe via RSS , email , or Twitter! Inactive RAM memory? Its causing problems and its not really a great thing to have. When RAM is inactive computer speed is questionable.

Most of users are having a hard time with it and machine is getting very sluggish. Its weird there is anything we need to do about inactive RAM but it looks like its not going to be solved so OSX takes care about it itself. If you are an intelligent computer user, you should do a reboot once every other day, if not everyday.

Fundamental elements here. After rebooting your inactive memory is cleared and only used if you begin to call on your hard drive. When your mac stores information as inactive memory, it will speed your system up, not slow it down.