Why is my MBP slow?

[Moocher]

When your computer starts running slowly quit safari and start it again. As far as I know safari still doesn't handle RAM very well, especially if it has been running for a while.

Mooch

 

[Jongewehr]

have you tried clearing your catche on FF an Safari?

 

[moral-hazard]

The page in : page out ratio is really bad.

It should be at most 100 : 15.

Before that though, does a restart change anything?

I will second both reboot and more ram as potential solutions.
Its easy to leave OS X running for weeks (months?) at a time and forget to reboot your machine. As stated:

OS X runs best with a lot of memory. It tries to keep a lot of stuff cached so it runs faster, but then it doesn't always give up that space to your programs like it should. Rebooting will clear out a lot of stuff cached in RAM.

The combination of these two things mean that it's very easy to page out if your machine has been on for a while. It's about 100,000x slower to get something off the disk than it is to get it from ram, so if you get to the point where your machine is thrashing and swapping out pages all the time between disk and memory, it's going to be slow.

 

[chill.]

go to utilities and open up console app and see if you have any errors. some programs that you install/uninstall can leave a lot of residual crap. it's best to do a clean reinstall of osx or use onyx to clean stuff out

 

[moral-hazard]

go to utilities and open up console app and see if you have any errors. some programs that you install/uninstall can leave a lot of residual crap. it's best to do a clean reinstall of osx or use onyx to clean stuff out

appcleaner is good too.

 

[chill.]

yea but appcleaner won't work for things you've already deleted