How to tell when to add memory?

Look at activity monitor after doing some work. Look at the page ins/outs. If your page outs are 10% or more of your page ins, time to add more.

 

Here's a useful link...

http://support.apple.com/kb/HT1342

 

Inactive makes me think that Apple have some work to do...

How often do you reboot your machine?

 

Page Outs. Simple, if the Page outs in your Activity Monitor are increasing from 0, then you really need more RAM. Otherwise, you are fine and its a lag issue.

 

You will find a pretty good explanation about "page outs" here

You can find your "page outs" by going using the Activity Monitor found in your Utilities Folder (use the System Memory tab).



Woof, Woof - Dawg

 

Hmm, this is under normal usage...I think I need more memory, too bad my computer is already maxed out

 

I seem to be having a similar problem. It seems as if OS X isn't releasing any memory back into the system reservoir. this is a picture from just a normal days use i.e.very little final cut use along with itunes safari and mail. nothing major at all.

 

i believe that wired is what you are actually using at the moment. as someone else said before, if you start up a big program even for a second and it allocates 2gb of memory, and you close it down, the 2gb will become active memory. inactive memory is there for reserve and free means its not being touched at all. i think

 

now to get even stranger... I rebooted and only 4 gb show up

 

check the RAM in the risers...make sure everything's plugged in properly

you DEFINATELY need a scratch disk for photoshop

from memory, as CS4 for mac is still 32-bit, it will only directly use 2.7-3.3GB RAM...however, i remember reading somewhere that it can use extra RAM as a scratch disk anyway.

sorry if that's a bit vague, but i recommend that you get a scratch disk first...then see what you think

 

Genny, Genny,

I agree with your assessment and recollection but not the recommendation. Go for the RAM first. It will help everything run faster and/or smoother! Adding a scratch disk may not noticeably improve anything unless his current scratch unit is fighting for drive access with another app of some kind.

Also yes, pull your RAM trays and reseat the RAM modules! RAM sockets and RAM thermal sensors in the Mac Pro are weird - touchy-weird!