Help with Activity Monitor

[TheSpaz]

I've been monitoring my RAM usage lately and I really don't fully understand all the terms in Activity Monitor. I would love to understand more about what's going on with my RAM usage and Virtual RAM. Here's some questions:

What is Wired RAM?
What's the deal with Page in/Page outs?
Why does each App have it's own Real Memory and Virtual Memory allocations?
Why is my Virtual RAM so big? (5GB for example)
How come Inactive RAM isn't the same as Free RAM?

I hope there are people who can explain to me how I can check to see if the amount of memory I have is optimal for my work (and play) habits.

 

[WildCowboy]

Have a look at this document to help you understand the different categories of RAM.

Page outs are an indication of insufficient RAM, as they are a measure of data being swapped out to disk as the RAM fills up. Completely avoiding page outs is nearly impossible, but you don't want too many. A better indication of your RAM needs is how your system feels. Does it feel laggy? Do you get a lot of beachballs?

 

[Eraserhead]

Page in's is reading from the HD, Page out's are writing out to the HD. If you have lots of Page Outs over a short period you need more RAM.

 

[TheSpaz]

Page in's is reading from the HD, Page out's are writing out to the HD. If you have lots of Page Outs over a short period you need more RAM.

Ah I see.... So page INS are good but a lot of page OUTS mean that information from RAM is being written to my drive thus slowing down my machine because it's accessing that information back from the drive. I do notice that I get a LOT of page outs... so maybe I made a smart move by ordering 2GB more RAM. That gives me 3GB all together. It should be here by tomorrow. I do notice that my hard drive is clicking a lot.

 

[Eraserhead]

Yeah you'll want more than 1GB in a Mac Pro.

 

[TheSpaz]

UPDATE: Here's the deal. I was watching my RAM usage at home and I noticed that when I rebooted, I was presented with a fresh "0 page outs" and all was good. Then I launched Safari and instantly got 137 page outs! I was only running iChat, and Safari. Then I ran EyeTV software and watched some TV and the page out number did not change. Then I recorded some TV while I went downstairs to watch the show and went to bed right after it was done recording. Then when I woke up this morning, I checked my page outs and it was 28,000!!! What is my computer doing at night where it's paging that much? I hardly used any Apps!

However, at work on a G5 with only 1GB of RAM also:
I run Illustrator almost all day long
Photoshop runs in the background all day
Safari
Quark Xpress 6
Suitcase X1
Indesign

I do this stuff all day at work... working on different files, activating fonts and working in Photoshop and Illustrator a LOT and my page out number is still "0". It seems like the G5 is using a lot less memory using ALL of these Apps than my Mac Pro uses when I'm just surfing the web or using iChat. It's very weird. Do I have a memory leak somewhere?