virtual/real memory

[instant.human]

hey there... maybe its a stupid question but here we go:

i was noticing that my mac osx 10.4.10 was slowing down. not really getting really slow but yet slower. its not because of 10.4.10, my boottime was at 1 minute back in 10.4.8. well yea so i checked the activity assistent (dont know if its the correct english name though, you know what i mean) and checked the memory used.

i stat always told me that i only had like 150 mb free (1gb) and that freaked me out, because i had like itunes and firefox running and that causing so much memory to be used? didnt know.

so i checked and saw, for example, that firefox uses 60mb of pysical memory and 412mb of virtual memory.

of course i know that with the time your system gets a little smaller than it was back in the days when it used to be a brand new install, clear on that and i know certainly that some apps use more, some less memory.

what i dont really understand is that whole virtual memory-thing. why the heck does firefox, and 60mb already seems a lot, use 412mb of virtual memory? what for?

you know im not a speed freak, i can live with photoshop taking 2 seconds longer to load and stuff but i freak out if a certain point is surpassed.

if i get under 20gb of hdd-space i start to clean up my apps and stuff. and if the smallest part of the pie is the green one, looking at the activity monitor, i just want to know why and what i can do.

i know that dashboard uses reccources although its not running atm, just for the record.

that transmission uses like 50mb of physical ram space... i didnt know that, its pretty much imho but yea..

some addidional info:

most of my discspace is taken up by music and documents, i only have a few apps installed, only the neccessary ones for what i do. im on a

blackbook c2d 2,0

1gb ram

120gb hdd

mac osx 10.4.10

maybe you can help me understand everthing a little better. :)

and please dont come here to flame me and say "dont buy a freaking mac if you dont know what virtual memory is about", i bought a mmac because i dont have to worry about those things too much. if i were interested in all that diggedy i would use linux, i guess.

thanks and cheers! =)

[the evn show]

There's a plenty of text but not a lot of question. Please, summarize what exactly you want to know.

• You feel like your mac is getting slower, not really, but maybe...well...
  
• Your boot time was 1 minute around the time of 10.4.8
  
• You've looked at activity monitor and don't really understand the numbers
  
• Photoshop may or may not take longer to load and you will care if it takes too long sometime in the future.
  
• Hard drives and green pie.
  
• You have lots of data and very few applications
  

Do you just need a breakdown of what unix VM metrics mean or is there some other question here?

[Miuku.]

I'll try to present this in as understandable form as possible - since many of the users that wonder "Where's my memory?!" come from Windows where unused memory is good.

On Unixoids (and I loosely include Linux and OSX in this group) the philosophy is: Unused memory is wasted memory. Hence the operating systems try to cache as much data as possible - this means if there is any memory available, the system will attempt to hold used data in there just in case another application requires it.

When another application requires this memory, it is automatically released - thus unless your wired and active memory caps your 1GB, you don't have a worry in the world. VM usage is pretty much insignificant - applications often reserve much more memory than they actually use, it doesn't mean that the application actually *uses* that much memory however.

For a "Memory for dummies" explanation of it:

http://docs.info.apple.com/article.html?artnum=107918

edit: Le typo.

Edited October 10, 2007 by daPhoenix

[markwolfe Veteran]

  redmosquito said:

...

so i checked and saw, for example, that firefox uses 60mb of pysical memory and 412mb of virtual memory.

...

why the heck does firefox, and 60mb already seems a lot, use 412mb of virtual memory? what for?

It sounds like this is the gist of his question.

Firefox, even on my Linux box, uses a lot of memory over time. I think it caches about everything, thinking that it may need it again if the user bounces back to previous pages.

Are other apps causing you concern, or is it primarily firefox that you are noticing this large allocation?

[instant.human]

^firefox was just an example. transmission uses plenty of ram aswell, just as itunes (of course) and quicksilver.

the evn show:

sorry, i like to talk much. especially to cover up my bad english. ;)

your summary doesnt really sum it up. most of the things are clear to me, i because as you see there is much text but few question. :)

sorry if that offended you and thanks for the help.

daPhoenix:

that more or less explains it all.

"unused memory is wasted memory" explains it all to me. thanks.

i actually use macs for quite some time now, since 10.3. i guess but i never actually thought about it, until today. sometimes you just get bored and look what going on. :)

thanks, anyways.

[CPressland]

Well, I joined the discussion a little late but you say your Mac is starting to slow down lately? well, you could consider running the daily, weekly, monthly sudo task thing? Just an idea, either that or leave it on for a few days and it'll clean itself up :)

But yes, Mac uses all available memory so all applications run fast :)

[instant.human]

i shouldve mentioned that i only restart when necessary, i hardly never put it off actually. i know its not that necessary with macs.

thanks for the info anyways.

i just mentioned it because i noticed it when restarting after updates or whatever.

[CPressland]

Well in that case, the only thing I can recommend is upgrading to 2GB of RAM.

[instant.human]

im definately planning to do that as soon as leopard comes out. new hdd, new ram, new os...

[instant.human]

so in favor to open a new topic i hope some people take a look at this one:

i was trying out the vitae customization whatever for mac (the installer) because it looked great on the screenshots. it didnt in real imho so i ran uno over it, i run uno anyways and it was back the way i liked it.

i wanted to open up itunes but it said "itunes could not have been opened because theres not enough ram" or equal, i dont know what exactly this is in english.

whatever, so i launched activity monitor because i wanted to check and saw this:

i launched photoshop cs3 extended and it worked like a champ so i was a little worried if something is messed up...

what the hell COULD that be? what may i be able to do?

thanks in advance.

[Miuku.]

Why do you have antivirus software using almost 100MB of your mem?

You really don't need one at the moment, it's a waste of resources and in the case of your program an insane waste.

[instant.human]

yea i know i just install it to scan for virusses once in a while, cant hurt, i guess.

problem is solved, by the way...

i did a fresh install of itunes. i just didnt thought that would solve it... sorry for asking anyways.