Is this normal?

I have only a few apps open and 8 gb of ram, an look how almost everything is used...
I hate it!! why does that happen?

What version of OS X are you running? Safari is using a lot of your memory as you can see. (Everything else looks normal.) However, the last update to Safari (along with Lion 10.7.4) supposedly fixed that. Reboot and open Activity Monitor again, I think you'll find quite a difference in Safari's memory usage.

t4ggs said:

I have only a few apps open and 8 gb of ram, an look how almost everything is used...
I hate it!! why does that happen?

Click to expand...

The inactive RAM is basically RAM that OS X will automatically free up "if" it is needed. At the moment, it's simply not needed. OS X leaves whatever software that was running in that space alone as long as that space is not needed for other tasks so that it will load faster if you re-run it. In other words, this is a non-issue. Inactive RAM is available free RAM if needed.

t4ggs said:

I have only a few apps open and 8 gb of ram, an look how almost everything is used...
I hate it!! why does that happen?

Click to expand...

Another alternative (if you want to see more "green") is to reboot the computer.

- Nick

lifeisabeach said:

The inactive RAM is basically RAM that OS X will automatically free up "if" it is needed. At the moment, it's simply not needed. OS X leaves whatever software that was running in that space alone as long as that space is not needed for other tasks so that it will load faster if you re-run it. In other words, this is a non-issue. Inactive RAM is available free RAM if needed.

Click to expand...

Absolutely - inactive is, for all intents and purposes, free.

If for some reason you'd like to clean out the inactive RAM (for whatever reason), this can be done by purging it. However, it's rather pointless to do so.

As for Safari, my experience has taught me that it leaks memory left, right and centre (even with the new up date). This problem isn't exclusive to Safari however - many applications leak memory. As such, it might help to restart applications once in a while.

I'm running OS X 10.7.4, the latter version, everything is up to date and everything is legal.

This happens to me once per week and the computer start running very slow so I have to reboot or to free up memory (using an app from the app store), or quit most apps...

The thing is I'm not running many apps, and neither one is taking to much ram, the problem seems to be that the OS is not freeing memory... why?

It's not how many apps you're running but which ones. You may only run a few apps but if they all use a lot of memory, you'll run low.

I added up the memory usage for the top ten processes there and it came out to 3138MB or 3.06GB. Safari alone, adding up what it's responsible for, is using 1239.7 or 1.21GB. That's one application using more than a GB of RAM. Safari is especially problematic - numerous updates have come out promising to plug the leak and, in my experience, it never gets fixed. To be fair, other browsers leak memory as well (such as Firefox which has admittedly gotten better).

This is one of the side effects of out of process plugins or the separation of processes in browsers. All major browsers (Safari, Firefox, Chrome and Opera) separate some part of the browser's operation into separate processes - you can see that above in your screenshot of AM (Safari has three processes: the main one, web content and it created one for Flash). This makes the browsing experience more stable since if Flash were to go crash on you, it wouldn't take down the whole browser. Unfortunately, it seems that the separation of processes consumes more memory. As such, you would be best to restart Safari once in a while.

Thanks, but my question is: Why my computer feels slow? why the OS won't free the memory automatically?

That's my point - it's not the OS, it's the applications. The OS can only free memory that isn't being used and in your case, applications are using it and eating it up constantly.

Using the discussion above, OS X can't release memory that Safari is using - that doesn't make sense and would cause huge problems. Since Safari is controlling that memory, OS X marks it as "out of reach" so to speak and can only manage that memory once Safari lets go of it. Once you quit Safari, OS X will take over and release that memory, allocating it to other processes or releasing it to the pool of free memory.

but if you see the chart there's a lot of inactive memory (the blue slice)...it means that memory is not in use

Yes, but as lifeasabeach noted, that is part of how OS X manages memory. You'll always have inactive memory and if the OS or an application needs it, it will be allocated it. In other words, it's memory that is reserved for the application that was using it but if it is needed elsewhere, it will be re-allocated. Thus, as I said earlier, it is for all intents and purposes "free memory." Do not count that as used memory.

You've got 5.12GB of memory being used (wired + active). Given what I calculated above, that's reasonable. You've got a whole host of processes that I can't see in that list but the processes that I can see are collectively using 3662.5MB or 3.58GB. It's possible that the remainder of the processes open are using 1.52GB of memory.

vansmith said:

Yes, but as lifeasabeach noted, that is part of how OS X manages memory. You'll always have inactive memory and if the OS or an application needs it, it will be allocated it. In other words, it's memory that is reserved for the application that was using it but if it is needed elsewhere, it will be re-allocated. Thus, as I said earlier, it is for all intents and purposes "free memory." Do not count that as used memory.

You've got 5.12GB of memory being used (wired + active). Given what I calculated above, that's reasonable. You've got a whole host of processes that I can't see in that list but the processes that I can see are collectively using 3662.5MB or 3.58GB. It's possible that the remainder of the processes open are using 1.52GB of memory.

Click to expand...

I think the OP gets that point by now.. or at least hope so. But I think that there's something being overlooked and it's something that those in the "That's just how OS X handles memory and there's nothing wrong with it" camp, have never been able to be open minded about. If you look at the original post, t4ggs states that he/she has 8 gigs of physical RAM. That's quite a lot, especially given the small amount of apps running.

It doesn't matter that Safari is a pig, nor does it matter that half the RAM is being allocated in some way, active or inactive. There's still plenty of free RAM to go around, and t4ggs is saying that he has to reboot often because things slow down too much. IMHO, there's something else going on, but I'm not sure that this behavior is due to available RAM or an app which is hogging the system, or something else.

I won't rule out memory handling until they figure out what is eating system resources and such. I'd perhaps suggest systematically leaving specific apps out of the equation until things return to "normal".

1. Download Firefox or Chrome
2. Do a hard boot, total system shut down and restart.
3. Use the new browser for a while and continue other operations as you'd usually do.
3. Problem persisting? Reboot again and try not using a regularly used app, see what happens. Are there any apps starting up in your "Login Items" under "users and groups" in System Preferences? Get rid of them if so.

I've been running an extremely stable 4 year old MacBook Pro that initially had 2 gigs of RAM (updated to 4 by me) and I use resource hungary apps regularly. Photoshop, Lightroom, Aperture, Garageband, etc.. and my system never hangs or gets very slow. When it does, I quit said apps and things get better immediately. I started with Leopard, went to SL then Lion and things have always been the same.. very stable. I only ever install the OS clean, never on top of the old one.

But could it be memory handling? Again, I wouldn't totally rule it out... but I'd look elsewhere first.

Doug

Maybe we can shift the conversation to look at CPU usage - that could very well be the source of the problems here. Try Doug's solution to see if any one app is causing the problem.

t4ggs said:

I'm running OS X 10.7.4, the latter version, everything is up to date and everything is legal.

This happens to me once per week and the computer start running very slow so I have to reboot or to free up memory (using an app from the app store), or quit most apps...

The thing is I'm not running many apps, and neither one is taking to much ram, the problem seems to be that the OS is not freeing memory... why?

Click to expand...

As has been pointed out, I already pointed out that the inactive RAM technically is in fact free RAM. This is NOT the source of whatever slowdowns you are having. By comparison… I have 16 GB of RAM and right now, I have roughly:
37 MB free
1.2 GB wired
2.8 GB Active
12 GB inactive
15.9 GB used

The key word here is "active". Used RAM is not "used" in the sense that it isn't available for use. On the surface, it seems that ALL of my RAM is eaten up, but my system is not slowed down. Not sluggish. Working very very well in fact. The system is really only using about 4 GB of that 16GB of RAM and if I launch something that is memory hungry, that inactive RAM will immediately be freed up to accommodate it.

Ultimately… my point is that something else is wrong with your system. What that is, I cannot say, but more likely than not some 3rd party software you are running that is misbehaving. Unlike the sentiments of others here, I have no issues with Safari eating up my RAM and I use that almost exclusively. You can use something else if you want to rule it out, but I'm skeptical that it is the problem. See my signature for the more typical culprits.

lifeisabeach said:

Unlike vansmith, I have no issues with Safari eating up my RAM and I use that almost exclusively.

Click to expand...

Fixed that for you.

I want to jump to one thing that hasn't been discussed - the kernel_task process. Your kernel_task process is using up a lot of memory - 900+ MB is excessive. I've had my MB on for a few hours and it's only using 214MB. Now, I don't have as much RAM (4GB here) but you still shouldn't be experiencing such high usage. When was the last time you rebooted?

Also worth noting: since the kernel can't restart itself while the computer is on (that logically doesn't make sense), the amount it will use will only ever grow. As noted in this article:

For instance, on my MacBook Pro running OS X 10.7 Lion, an initial boot will show the kernel_task process taking up 330-340MB of RAM. The task will idle with this level of RAM until you decide to do something with your system, so if I open a few applications (Word, Pages, iCal, Safari, Preview, etc.) then the amount of RAM used by the kernel_task increases to around 370MB. At this point the system has loaded and interacted with some services these programs need (networking, authentication, firewall, graphics, and user input), so the kernel_task has increased its RAM footprint to accommodate those tasks being active. If the programs are quit, the kernel_task does not relinquish the new RAM it's using, since the system services are still active even though the programs themselves are not. On subsequent launches of these programs; however, the RAM footprint does not increase any further.

Click to expand...

The more processes that require kernel resources will cause the kernel process to grow and that memory usage won't shrink. This may not normally be a problem but if the kernel is continually being called to manage services, that may cause it to grow (in terms of memory consumption). Like all other memory issues, a reboot would fix that. As such, I'd suggest that you watch that process as you do your daily activities.

Ok, first of all thank you all for helping.

Let me clarify some things:
The problem is not CPU, nor the HD (I've lots of free space), not an app hanging the whole system.
The problem is that when most memory is in use or inactive, the mac becomes very slow, and what I need to do to solve the problem is freeing memory manually (I use an app called Purger King, from the app store).

And the problem is that the OS is not freeing the memory automatically.

About the RAM... Some minutes before that screenshot I was using Parallels with Windows 7...and the Kernel is maybe because I'm using wifi, an external monitor, and an external keyboard...

To be honest, there isn't enough information in this thread to say what the problem is, or isn't.

Dysfunction said:

To be honest, there isn't enough information in this thread to say what the problem is, or isn't.

Click to expand...

What is needed?

t4ggs said:

The problem is that when most memory is in use or inactive, the mac becomes very slow, and what I need to do to solve the problem is freeing memory manually (I use an app called Purger King, from the app store).

Click to expand...

Ignore the inactive value. While it is reported as "in use," in actuality, it's not in the purest sense of the term.

t4ggs said:

And the problem is that the OS is not freeing the memory automatically.

Click to expand...

OS X wasn't designed to purge inactive memory. In fact, that would defeat the purpose of inactive memory. If you purge it, you'll reclaim it but application launching will take longer. You'll have to decide if that's worth it. However, you shouldn't have to purge it because if your system ran out of memory, it would simply start using up the inactive memory.

t4ggs said:

About the RAM... Some minutes before that screenshot I was using Parallels with Windows 7...and the Kernel is maybe because I'm using wifi, an external monitor, and an external keyboard...

Click to expand...

Parallels, and all VM products, interact with the kernel. Using Parallels will likely force kernel_task to use more memory but not significantly more (I just launched VirtualBox and it only forced kernel_task to use up another ~17MB).

vansmith said:

OS X wasn't designed to purge inactive memory. In fact, that would defeat the purpose of inactive memory. If you purge it, you'll reclaim it but application launching will take longer. You'll have to decide if that's worth it. However, you shouldn't have to purge it because if your system ran out of memory, it would simply start using up the inactive memory.

Click to expand...

I understand, but if I don't purge it manually, it becomes really slow and it doesn't work... why the OS won't purge it when reaching a certain level?