With regard to 4GB in the G5, yeah I've seen that it's the "sweet spot", too -- the consensus seems to be that by filling all 8 ram slots, the I/O to memory is maxed out (as the system simultaneously accesses all 8 modules); since 512 dimms are the best deal, i think, (4GB of top-tier memory for around $700) that's the way to go for max performance without breaking into the VERY expensive 1GB module territory. at least, that's the theory, as far as i understand it.... still waiting for rev. b powermacs to come out -- and still re-iterating my wish that apple could sell a "bare-bones" machine with no vid card, no HD, and no RAM, but that would be just plain silly on Apple's part! 🙂
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Just how much Bloody Ram does it need.
- Thread starter adamfilip
- Start date
- Sort by reaction score
Yes: Open another application that uses it. Inactive RAM is just that; inactive. If the program that originally put stuff there asks for it again, it immediately becomes active. If some other program nees that RAM, it immediately gets allocated to that program. For all practical purposes, inactive RAM = free RAM. It's just not something to worry about.adamjay said:
Sounds like it's having both apps open at the same time that's the issue, not anything to do with inactive RAM. If Final Scratch has actually allocated most of your RAM to itself (not inactive), then there might not be much left for Audio Hijack, and you could get glitches as the OS pages memory to disk. Or, it could just be a processor and/or IO issue--not enough bandwidth for both apps to do what they need to do.adamjay said:
But in any case, once you quit Final Scratch, all of its formerly used RAM should immediately become inactive, at which point it's available for any other app to use, exactly as if it were free.
adamjay
macrumors 6502a
Makosuke said:
actually, it was turning the free ram into inactive ram, so i guess its not that detrimental.
as for the glitches in audio hijack, i found out that it is simply an issue with processor power. i was getting glitches when recording to compressed .mp3 files. , however when recording to uncompressed stereo .aiff - no glitches at all. so it seems that between recording to disk, running finalscratch, and encoding to mp3 - it was just all overkill. no big deal, i can make .aiff's up to 2GB's and thats 3 hours of audio!, if i need to go over 2GB i can set audio hijack to start a new file every 2GB and just fix it later in Bias Peak.
but thanks for clearing up the definition of inactive ram, it all makes much more sense now. while i'm at it, can i pick your brain for the deferences between (in activity monitor) Nice vs. Idle vs. System CPU usage???
i just started Folding and i see it requires alot of "Nice"
Easy one; "nice" is just that--a process that is using processor cycles, but will immediately allow any other application to use the processor if necessary. It's basically used by processor intensive but non-important things, where it doesn't matter if something else preempts it.adamjay said:
Hence, it's perfect for Folding; it'll use all of your available processor time when nothing else wants it, but as soon as you launch another app that asks to use the processor, Folding backs off and lets it do its thing. Nothing goes to waste, save maybe a bit of overhead to keep Folding running and handle the processor scheduling. It'll really jack up the power use of a G5 or a laptop, but it won't otherwise affect your other applications much.
musicpyrite
macrumors 68000
I have 256 MB of RAM and I'm always runnig Safari, iTunes, iChat, and usually Appleworks, in addition to LimeWire, Adobe Photoshop CS, iMovie, and Micromedia Dreamweaver MX. I only notice lag when switching between apps. Do you think I need more? 😕 😕 😕
Counterfit
macrumors G3
MacRAND
macrumors 6502a
G5s need a couple of GB RAM at least.
G5s are notorious for eating RAM.
The graphs I've seen, seemed to show efficiency begins at 1500 MB, increasing significantly through 2500 MB, then tailing off rapidly.
Obviously, 4 GB cannot hurt.
If you have a dual, you have 8 slots, @ 512 each that's 4 GB max.
However, now that 1 GB chips are commonly available, if you do high end stuff, 8 GB may be more appropriate.
Although Apple states 8 GB max, with the advent of 2 GB RAM chips your G5 can handle 16 GB total.
But unless you are a high end video editor or someone who regularly deals with multi GB files, that much is insane - including the COST!
I feel the sweet spot for a dual G5 is most probably between 2.5 and 4 GB depending upon the demands you put upon your PowerMac.
Just don't waste your slots on less than 512 MB boards, 2 matching boards at a time.
If you already own a smaller pair and have the slots, you might as well use them until you they get displaced by larger pairs.
Until I maxed out RAM in my iBook (originally 128 MB added upon purchase free) with a new 512 MB, it was hurting - now it runs smoothly. But, that's a G3...maxed.musicpyrite said:
G5s are notorious for eating RAM.
The graphs I've seen, seemed to show efficiency begins at 1500 MB, increasing significantly through 2500 MB, then tailing off rapidly.
Obviously, 4 GB cannot hurt.
If you have a dual, you have 8 slots, @ 512 each that's 4 GB max.
However, now that 1 GB chips are commonly available, if you do high end stuff, 8 GB may be more appropriate.
Although Apple states 8 GB max, with the advent of 2 GB RAM chips your G5 can handle 16 GB total.
But unless you are a high end video editor or someone who regularly deals with multi GB files, that much is insane - including the COST!
I feel the sweet spot for a dual G5 is most probably between 2.5 and 4 GB depending upon the demands you put upon your PowerMac.
Just don't waste your slots on less than 512 MB boards, 2 matching boards at a time.
If you already own a smaller pair and have the slots, you might as well use them until you they get displaced by larger pairs.
adamfilip said:
There is also an issue with Safari having a memory leak - http://www.dasgenie.com/scrap/archives/000007.html .... Once every few days I just quit and restart safari, which brings it back to normal levels (70 mb).
RAM usage explanation from a Unix guy
Every 2 months or so, somebody wonders aloud why OS X seems to require huge amounts of RAM to do nothing. 🙂 This is a perfectly reasonable question, especially if you used previous versions of the Mac OS. After all, in OS 9 and earlier, you had to manage your memory carefully. There was only so much to go around, and you could actually instruct a program as to how much to use.
Keep in mind though, that OS 9 can trace its lineage directly back to the OS that shipped with the original Mac. We're talking early 1980's memory management technology here: The user. Back then, no home users had a gig of RAM and 20 apps running on their boxes simultaneously. There weren't 16 users logged in and doing all sorts of things at once.
Welcome to Unix, my friends.
Unix-like operating systems had to manage their memory, and do it well. Unix has been a multi-user OS from its humble beginnings in academia. 20 physics researchers logged in and running simulations? You better have a good memory manager, lest researcher A's data accidently mingle with researcher B's ... who wants to sort that out ? Not the Unix sysadmin guy - he had better things to do, like play Nethack and Netrek. 🙂
Why is OS X Using All My RAM?
Good question. We'll get to that in a second. But an equally valid question that no one ever asks is: Why isn't my operating system using all my RAM? You paid good money for it, didn't you? Wouldn't you want to get your money's worth? What good is RAM if it sits there doing nothing? The point of memory is to store information. If it's not storing anything, then there really isn't much point to having that RAM.
Here's where OS X (and other Unix / Unix-like OSes) differ from what many Mac users are used to:
The philosophy behind memory management in OS X is that unused memory is wasted memory. Accessing the disk is slow. On a multi-user system, if things get slow, users complain and we sysadmins get very, very unhappy. So, OS X is designed to keep information "handy" in RAM. People are creatures of habit - we tend to do the same tasks over and over.
So, if you've been browsing the net and then close Safari, there's still a pretty good chance that you'll open it up again. Why free up all the RAM that Safari was using the instant you close it, if you're going to turn around and re-open it five minutes later?
Instead, OS X keeps some of that data laying around in RAM for when you next open Safari. But, it marks the memory as inactive. When you next try to open Safari, there's less to load in from disk because OS X can access data from the Inactive memory pool. Therefore, Safari loads faster and people are happy.
But wait! What if I never open Safari again? Or what if I open a really huge honkin' Photoshop file and need that memory back? Is there any way to get it back?
You're in luck. OS X does this for you automatically too! Notice earlier I said that RAM that stored information that was no longer in use was marked inactive. RAM that contains nothing at all is called "free" memory. OS X always tries to keep a certain amount of free memory. If you suddenly open a huge document that eats up a bunch of your free memory, OS X will automatically empty some of your inactive RAM and turn it into free memory, making it available for new programs to use.
OK, so I get it. Inactive RAM is like a buffer - OS X keeps data around in inactive RAM in case I use it again. But if I don't, OS X will free up the inactive RAM and allocate it to new programs automatically.
So, that about covers it. The next time you notice that you've only got 7 megs of free memory left in Activity Monitor (or top from the Terminal), check to see just how much memory is Inactive. You've probably got more than enough for your needs. OS X is just doing its best to make your user experience a fast and pleasant one.
Like I said: You paid for the RAM? Why wouldn't you want to use it all?
Hope that helps.
(note: the above is a simplistic view of what's going on, but accurate enough for most purposes. Any BSD or mach kernel hackers that might be reading this, sorry if I've glossed over any of the details. 🙂
Every 2 months or so, somebody wonders aloud why OS X seems to require huge amounts of RAM to do nothing. 🙂 This is a perfectly reasonable question, especially if you used previous versions of the Mac OS. After all, in OS 9 and earlier, you had to manage your memory carefully. There was only so much to go around, and you could actually instruct a program as to how much to use.
Keep in mind though, that OS 9 can trace its lineage directly back to the OS that shipped with the original Mac. We're talking early 1980's memory management technology here: The user. Back then, no home users had a gig of RAM and 20 apps running on their boxes simultaneously. There weren't 16 users logged in and doing all sorts of things at once.
Welcome to Unix, my friends.
Unix-like operating systems had to manage their memory, and do it well. Unix has been a multi-user OS from its humble beginnings in academia. 20 physics researchers logged in and running simulations? You better have a good memory manager, lest researcher A's data accidently mingle with researcher B's ... who wants to sort that out ? Not the Unix sysadmin guy - he had better things to do, like play Nethack and Netrek. 🙂
Why is OS X Using All My RAM?
Good question. We'll get to that in a second. But an equally valid question that no one ever asks is: Why isn't my operating system using all my RAM? You paid good money for it, didn't you? Wouldn't you want to get your money's worth? What good is RAM if it sits there doing nothing? The point of memory is to store information. If it's not storing anything, then there really isn't much point to having that RAM.
Here's where OS X (and other Unix / Unix-like OSes) differ from what many Mac users are used to:
The philosophy behind memory management in OS X is that unused memory is wasted memory. Accessing the disk is slow. On a multi-user system, if things get slow, users complain and we sysadmins get very, very unhappy. So, OS X is designed to keep information "handy" in RAM. People are creatures of habit - we tend to do the same tasks over and over.
So, if you've been browsing the net and then close Safari, there's still a pretty good chance that you'll open it up again. Why free up all the RAM that Safari was using the instant you close it, if you're going to turn around and re-open it five minutes later?
Instead, OS X keeps some of that data laying around in RAM for when you next open Safari. But, it marks the memory as inactive. When you next try to open Safari, there's less to load in from disk because OS X can access data from the Inactive memory pool. Therefore, Safari loads faster and people are happy.
But wait! What if I never open Safari again? Or what if I open a really huge honkin' Photoshop file and need that memory back? Is there any way to get it back?
You're in luck. OS X does this for you automatically too! Notice earlier I said that RAM that stored information that was no longer in use was marked inactive. RAM that contains nothing at all is called "free" memory. OS X always tries to keep a certain amount of free memory. If you suddenly open a huge document that eats up a bunch of your free memory, OS X will automatically empty some of your inactive RAM and turn it into free memory, making it available for new programs to use.
OK, so I get it. Inactive RAM is like a buffer - OS X keeps data around in inactive RAM in case I use it again. But if I don't, OS X will free up the inactive RAM and allocate it to new programs automatically.
So, that about covers it. The next time you notice that you've only got 7 megs of free memory left in Activity Monitor (or top from the Terminal), check to see just how much memory is Inactive. You've probably got more than enough for your needs. OS X is just doing its best to make your user experience a fast and pleasant one.
Like I said: You paid for the RAM? Why wouldn't you want to use it all?
Hope that helps.
(note: the above is a simplistic view of what's going on, but accurate enough for most purposes. Any BSD or mach kernel hackers that might be reading this, sorry if I've glossed over any of the details. 🙂
OSX is based on UNIX and since it's supposed to use true multi-tasking and not multi-switching like Windows9.x/XP you should have nothing to worry about. Gotta love that UNIX.
Nny
macrumors regular
Zorkon said:
Amen! Same goes for processor power. I realized that some apps can use quite a hefty punch of MHz if you let them. Why shouldn't they? My computer is no less responsive because of it. If I launch more apps then the greedy program relaxes a bit. I started doing Folding@Home so I make sure I get my "money's worth" for my processor. I am now at 0% Idle and I love it. No noticeable hit to performance at all and I am doing it for a good cause! Wonderful!
I think Limewire is the main culprit. I notice my PBG4 slows way down when I'm downloading/uploading. But as soon as I turn off Limewire, everything picks right up again, especially web services.