MBP (2008) and OSX - reduce memory usage - why so much?

Hi all,

I just got a new MacBook Pro (MBP) with 4GB RAM. I noticed that OSX eats up lots of RAM without much applications running and even more so for the Virtual Memory (VM).

Out of the box, I just installed the following applications:
- Evernote ( very small program)
- Firefox ( nuff said)
- VMWare Fusion 2 ( see below)

Only Evernote Clipper is running in the background, but only takes 4 MB

I restart MBP and without running any applications, I went to Activity Monitor and only 3GB is free. Where's the other 1GB go? Most of the default process is even taking like 950MB+ of VM.

In my WinXP pro, with 3 of the above installed and restarting the OS, I only use 600 MB of RAM (from Task Manager).

OK, so I tried running a VMWare instance (WinXP) with 2GB RAM set aside for the VM instance. I thought "Well, 3GB free...2GB taken..so I should have 1GB free, right? WRONG... Activity Monitor shows I only got 40 MB free.

So what's going on? Is tehre memory leak or something in OSX? How come it uses so much RAM out of the box (from a restart even)?

Is there any "Services" type that I need to turn off from OSX? I don't know where to look...

 

check the activity monitor, just type it on the spotlight

 

I did, that's how I found out about the excessive memory usage.

Trouble is, I don't know WHICH one I need to turn off... or how to do so.

As mentioned above, I am new to OSX and in WinXP, I can just turn off "Services", go to MSConfig for "Startup" application, etc.

Note that this MBP is brand new, so I haven't install anything other than the 3 harmless application above.

 

this indeed is abnormal! ... I have tasked my MBP (2.4 GHz 4GB ram) to about 10-12 applications at the same time and I still havent ever come near to maxing out memory. I no longer use VMware ... but even when i used to I dont ever recollect it having eaten up such a lot of memory...

 

Zambie,

When you start your MBP, how much memory did Activity Monitor reported? On mine, it reported that 3.12GB is free. Still seems a lot to me that OSX will be eating up 800MB+.

Is there anything that I need to turn "off" in my MBP to save the precious memory?

 

Ah, found this thread from Mac Rumors forum. Turns out OSX Leopard DOES takes bazillion RAM. More if more program is running...

It looks like Apple is banking on their RAM Optimization feature in OSX, which give back RAM when other applications need it.

Can anyone confirm?

 

O.S.X Does caching, same as Vista. That ram is not all for the O.S. It's also for programs it thinks you may need. It will adjust over time to your habits.

 

yeah, its caching, after you use a program, it will still retain the program in the memmory, until some other program needed it, that is.

vista do this also (caching in program after its been closed). vista also do pre-fetch, i'am not sure if leopard do the pre-fetch things, i dont think so though.

 

Just be happy you got the 4gigs of Ram -- goodness knows, I'm glad I upgraded out of the box. Take the Ram used for normal usage as you've said, and then add mother load programs such as office for mac (which I live in) and you are well over using 3 gigs of ram.

 

Also, Inactive memory is considered kind of free too.
For example, right now (running Tiger) I have:
Wired: 224
Active: 183
Inactive: 753
Free: 888

So, I still have 1.6GB to go (and that is with Eclipse, Firefox and some stuff running on the background.

(MBP 2GB RAM here)

 

What if you run VMWare Fusion? Granted, VMWare instances will eat up LOTS of memory depending on how much RAM you assign to the virtual machine. The thing is, it seems OSX eats up more RAM that effectively slows down the OS.

Here's the comparison:
1. WINXP
RAM: 4GB
VMWare: WinXP with 2GB assigned
Result: from fresh boot, run VMWare. Task Manager shows: 2.5GB used, the rest are free

2. OSX (MBP(
RAM: 4GB
VMWare: WinXP with 2GB assigned
Result: from fresh boot, run VMWare. Activity Monitor shows: 3.7GB used. Only 250MB+ is free.

This doesn't make sense: I only assign 2GB to the VMWare instance, why it'd take more than that 3.7GB?? Is OSX using 1GB RAM out of the box (without ANYTHING running)

So I just want to know is there something that running in the background that I can disable.

 

I have 2GB in my iMac and a fresh boot and a quick glance at iStat or Activity Monitor shows OS X has around 100MB Wired and 250MB active for a total of 350MB used. Inactive memory is memory that is no longer being used, but OS X is keeping cached for quick access in case you may need it later. If a program comes along that for some reason uses up all your free ram and still needs more OS X will allow the app to gobble up some inactive.

Read this: http://support.apple.com/kb/HT1342 if you haven't already.

Don't worry about VM usage...

Don't waste your time playing number games with your RAM usage. Unless you are experiencing disk thrashing, you don't need to obsess over it. 4GB is more than enough for OS X and all your favorite Apps. Although, you mentioned you were running a VM, which of course is going to gobble RAM. Just relax, close activity monitor, and have fun with your MBP.

 

OSX is really pretty interesting when it comes to memory usage. The less you have the less it will use, the more you have the more it will use, and while it seems to have a relatively high overhead with no applications running, it can run a LOT of applications very efficiently in less memory than you'd think.

I did some experimentation using a standard Macbook and Leopard using 1gb, 2gb, 3gb, and 4gb ram and comparing performance to a similarly configured XP Notebook (the XP notebook was fixed at 2gb).

With 1gb RAM OSX performed about as well as XP with 2gb. It used a bit more base memory but as more apps were loaded it handled them more efficiently memory wise.

With 2gb of RAM OSX was noticeably quicker than XP. OSX appeared to use even more base memory but even heavily loaded with apps it was more efficient and faster than XP.

With 3gb of RAM it was a bit quicker than 2gb but not significantly so. You could notice it the most when running a huge number of apps or a VM in addition to regular apps, but again it was not as big as I expected.

With 4gb of RAM there was no noticeable speed increase over 3gb, but battery life improved indicating swapping has pretty much completely stopped and the drive could often power down.

So I think 2gb is a sweet spot for regular apps and no VMs, 3gb is the sweet spot if you are also running a VM, and 4gb is a nice to have for a real power user or for improved battery life.

Right now I'm mostly using a MBA with 2gb and even running a VM its adequate but I'd prefer 3gb because of the VM. I use an iMac with 3gb a VM and a boatload of apps and its very snappy. On my MBP I like 4gb for the battery life improvement.

 

Same here, my macbook instantly uses up around 700-800MB of RAM without running any application.....two dashboard widgets and FanControl only.....running more applications and closing them afterward would increase to more than 1GB of RAM....as they are now wired for next time you open the same apps. I believe this is still better than VISTA's default settings right?

 

I'm pretty sure that if you assign 2GB of RAM to VMWare then 2GB is statically allocated to the VM. However, that isn't all VMWare takes since 2GB is basically for Windows while VMWare itself needs RAM it is it's own application and needs to translate all the calls between Windows and OS X. The VMWare translation app itself would be bigger on OS X since running Windows on Mac is more complicated than Windows on Windows. Like all DirectX calls have to be translated to OS X and the file system is completely different for instance.

When you say 250MB is free, does that include inactive memory? Because inactive memory is basically the same as free since it's given up instantly to new programs without complaints. Microsoft and Vista has been trying to fight the perception that having lots of free RAM actually means something which it doesn't. You'd much rather have 0MB of free RAM and everything devoted to inactive memory which has things cached for quick access if those are the files you need, but can also be given up without complaint to new programs.

 

It seems to me that OSX assigns as much RAM as it can to each task and throttles back when RAM is scarce. Running apps like Firefox, iTunes and Skype can see my RAM go to 75% but it never slows down so unless it's slowing your system down I wouldn't worry about it.

Something weird for me is that VMWare has 512mb assigned to it but it only uses 60-80mb!?!?

 

The main question you should be asking like grahamnp has hinted at is whether or not the performance of your MBP is suffering due to the way your MBP is utilising your memory. If the performance is not suffering, then why on earth do you even remotely care about how much of your many gigs of RAM you've bought, with the purpose to be used by your MBP to improve its performance, your MBP is using up.
If your MBP is taking ages to load an application because it's out of RAM and paging everything to the HD, then you have a problem.

 

When I first got my MBA a few months ago I started considering things I had not considered since PC days. This was because it had a low power processor, limited RAM, and a small slow hard drive and I was used to a maxed out MacBook Pro

Do I need a memory optimizer? Do I need a program manager? Do I need to start optimizing my disk? I actually did pick up software that could monitor and optimize such things.

But in the few months I've owned a MBA (the lowest powered, most constrained mac), even pushing it with usually a dozen or so apps running as well as a Parallels VM and a few Windows apps, it has yet to slow down or hang or blow up in everyday use - even though the monitoring software indicated some things were regularly maxed out. I have not had to actually USE any of the optimization software and now I no longer even bother monitoring. I figure at this point if I ever notice performance issues that are impacting my work, I can turn on monitoring stuff then.

So give your Mac the benefit of the doubt and let it take care of itself unless it gives you actual usage issues.

 

OS X manages memory just like vista or vicer versa....

It trys to consume/use all available RAM before having to use the hard disk for paging.

Using all available RAM vs paging on the hard disk increases performance significantly.

 

You have to understand how OS X works - the most important concept is this: It tries to use all available memory in order to make your computer as fast as possible.

It may seem counter-intuitive, and you'd think maybe you'd like to have some "spare". But in reality, OS X manages memory such that it's trying to use all of it.

The real measure of whether or not OS X is using "too much" or an unusual amount of memory is the size of the paging file. If the paging file grows beyond 64MB or 128MB, you know that the system actually hit a memory limit and is actually using more than your 4GB.

Before that, OS X will dynamically allocate memory such that you get the best app performance.

Windows XP is different - it doesn't really know what to do with memory past about 1.5GM or so, and even below 1.5B it is very inefficient with its disk cache. That's why you'll see lots of RAM free in XP. The disk cache is IMO the main thing that makes Windows XP much, much, much worse than OS X in terms of performance.

 

Sorry for the late response...
ahmmm... mine takes about 570MB of RAM when I just start up .. with airport on. That too with a number of processes running that are due to applications i've installed (e.g. logitech agent, li'll snitch, isolator, awaken help, growler, and a few more)... so.. i'ld reckon that would come down another 70 MB atleast had it been a clean install of os x leopard.

 

Thank you for the explanations! Coming from Windows environment, I have always experienced slow down when the memory falls down below 500MB.

So far, I have run VMWare all the time (added to "Login") and with 4-5 programs running, never at anytime I experienced any slow down. Leopard truly rocks!

FYI, I am running VMWare just to run my Outlook / iTunes combo to sync with my iPhone. Entourage and iCall is... unfortunately doesn't play well with iPhone syncing. Kinda funny that the sync integration works better in WinXP for a Mac product!