[JazzCatDRP]

First off, my apologies if this is the wrong forum...I didn't know where this would apply to.
This may be an incredibly stupid question so bear with me. From time to time I need to shut down my computer to free up RAM, fix a weird quirk that'll pop up, etc. I've heard in the past (related to Windows machines) that for a restart to be really effective, you need to shutdown, and wait 30 seconds for everything to "reset." Is this true regarding Macs?

[JHromadka]

Actually, I would suggest first trying a logout and then just log back in. That frees up a lot of resources (and keeps the uptime high ). Failing that, a regular restart does the trick for me.

The reason that Windows sometimes needs to be shutdown is that it has different variations of restarting. There is a quick restart that doesn't unload everything, and a full restart that is akin to Apple's method.

[Detrius]

First of all, no it isn't true.

Second, if you are running a stable version of OS X (e.g. anything recent), then you shouldn't have to do this anyway. You should only have to quit apps to free up RAM. At worst, you may have to log out to quit all of your apps. Free RAM is wasted RAM anyway. What kind of weird quirks are you getting that you have to reboot to fix?

Have you tried unlockupd? That fixes one really big weird quirk in OS X.

[Moose]

Originally posted by Detrius:
Free RAM is wasted RAM anyway.

And RAM that's tied up by leaks is well-utilized.

....

Sometimes, thanks to the way Mac OS X handles paging, a reboot after a few days makes things faster.

[OreoCookie]

Sounds like voodoo to me. I don't reboot unless I need to.

Whenever you launch an app, OS X caches some parts of it, so it will launch much faster than before.

Restarting sounds like a windows trick to me (and it works miraculously, especially when playing with network settings ).

[Moose]

Originally posted by OreoCookie:
Sounds like voodoo to me. I don't reboot unless I need to.

Your hard drive's probably faster than my 4200RPM laptop hard drive. You really notice paging on one of these.

[JazzCatDRP]

The biggest place I notice the computer dragging is in my browsers. I'll have nothing else open except two or three tabs and it'll just be CRAWLING. Restarting fixes it. For the record, I'm running on a Lombard G3 Powerbook with 384 meg of RAM, so it's not exactly a speed demon. I'll have to try the logging out and back in idea.

As far as the weird system quirks...it's really little things. For example, the other day, I couldn't get my Mac to recognize my external hard drive. I restarted and it was just fine. And there's been other little application quirks...some so small that I only notice because I'm picky

Also, I've heard that Mac OS X really shouldn't be turned off at all. Can someone explain that to me? I know it has something to do with the UNIX base, but beyond that I have no clue.

[sminch]

i believe (though my be talking utter pap) that unix runs all its maintenance doohickeys at night, so not turning it off at all (ie. leaving the machine running overnight) allows it to do its stuff and keep everything happy. if you leave it on and awake overnight, all good, but if it sleeps it won't wake up and do them...

if you use an app like mac janitor it'll do all the maintenance jobs whenever you tell it to.

sminch (who may be talking pap)

[sminch]

oreocookie, when you say that osx caches some parts of the app, what does that mean to the punters (like me)? ie. is the caching on the hard drive, not in ram? can the cache get full? will loads of caching slow things down?

i've really noticed that some apps, particularly neooffice/j, start up a lot slower the first time after a restart and i always wondered why that was, and whether the part that i now know has been cached is taking up memory or not (so whether having already run some apps and now having parts of them cached will slow down other apps afterwards...)

cheers for any explanations you can offer!

sminch

[Detrius]

Any RAM that isn't actively being used to store something else is automatically used as a disk cache. Anything you access on the disk has to be moved into RAM to be accessed. If there's nothing else that needs the RAM, it might as well stay there. That's what's meant by caching in this instance. So also in this instance, free RAM is wasted RAM.

And any leaking applications should be cleared up by a logout. If that doesn't do it, there's some serious bug in OS X that needs to be fixed... or you don't have enough RAM.

I maintain that I need 2GB of RAM for me and my wife to both be logged in with a half a dozen apps open. I only have 1GB of RAM, so if I don't log her out, I have 1GB or more of swap files.

[OreoCookie]

Originally posted by Moose:
Your hard drive's probably faster than my 4200RPM laptop hard drive. You really notice paging on one of these.

Same here, 4200 rpm notebook drive.

[OreoCookie]

Originally posted by sminch:
oreocookie, when you say that osx caches some parts of the app, what does that mean to the punters (like me)? ie. is the caching on the hard drive, not in ram? can the cache get full? will loads of caching slow things down?

i've really noticed that some apps, particularly neooffice/j, start up a lot slower the first time after a restart and i always wondered why that was, and whether the part that i now know has been cached is taking up memory or not (so whether having already run some apps and now having parts of them cached will slow down other apps afterwards...)

cheers for any explanations you can offer!

sminch

Like Detrius said, parts of the app remain in memory (memory = physical RAM + virtual RAM on your harddrive). That's what people sometimes see as OS X eating up their RAM. Obviously, those cached files (libraries, etc.) will be discarded when an app `really' needs the space.