[Eug]

I've heard that OS X gets rather annoyed when the boot drive's empty space shrinks below a certain amount. What is that amount, for say an average user who runs a bunch of memory hogging programs simultaneously and surfs a lot?

Is there a size that really starts to slow down OS X? Is there a size that causes problems in OS X function?

[seanc]

I think it's about 3 gigs. I'd try to keep at least 5 gigs free at all times.

How much space have you got left Eug?

[Eug]

Lots, but it's quickly disappearing. I have 70 GB left on my boot partition, but I've been adding movies to iTunes, and my encodes put them at around 2 GB each. I also need around to 15 GB for temporary ripped DVD images too. That means I only have enough space for about another 20 movies.

I could repartition my 500 GB drive, but I only have 90 GB left on my other data partition, so it doesn't really help me that much.

So, if I get a new iMac next year, I'm fine. I'll just get a 1 TB drive in the thing. In the meantime I'll have to repartition, or else make the entire 500 GB of my internal drive my boot drive, and use yet another Firewire drive as the data drive. However, I've already got 3 external FW drives attached to this thing (with two of them being backup drives).

[davidbk1]

It actually starts telling you to free space up. I think that happens around 300 MB free, but IMO you should never get there. I use 10% as a rule to keep the machine running fast.

My roommate's girlfriend managed to get down to 0KB. Even after freeing space in target disk mode, the machine refused to log in or change the password. Had to reinstall leopard

[Big Mac]

I actually ran my iBook's drive close to capacity for a number of months (say around 150MB free) under Panther. I didn't see any deleterious effects other than the occasional nag message.

[OreoCookie]

I've experienced very serious slow-downs when OS X had less than 3~5 GB of space left. Happened all the way from 10.1 to 10.4. My friends gave me a 250 GB harddrive for Xmas last year, so that I've enough space for now.

I think the effect is connected to the way OS X manages virtual memory: I'm a multitasking junkie. Usually, I'd have 10+ apps open at the same time. OS X creates new virtual memory files, but doesn't delete them until after a restart, so you will actually see the performance of OS X deteriorating. Depending on your cpu, OS X can manage 4 GB memory, hence you may run into trouble when you have only 3~5 GB left.

With desktops, avoiding this is much easier than with laptops, because I cannot replace the harddrive of my ProBook without voiding Apple Care. (On the MacBook, the harddrive is a user-replaceable part! :argh

[zykron]

My guideline is whatever matches the amount of RAM you have in the machine.

Since I have 1.25 GB in my iMac, I need to have at least 1.25 GB free at all times. (Since my 80 GB Hard Drive has over 50 GB leftover after moving a few files and putting others on CDs/DVDs, I'd say that I'm doing pretty well.)

[B Gallagher]

Originally Posted by OreoCookie 

With desktops, avoiding this is much easier than with laptops, because I cannot replace the harddrive of my ProBook without voiding Apple Care. (On the MacBook, the harddrive is a user-replaceable part! :argh

OreoCookie, you do realised that you can get Apple to replace the HDD in a ProBook for you, keeping the AppleCare valid? See this for more details. I did it a couple of months go with my MBP.

[OreoCookie]

Originally Posted by B Gallagher 

OreoCookie, you do realised that you can get Apple to replace the HDD in a ProBook for you, keeping the AppleCare valid? See this for more details. I did it a couple of months go with my MBP.

I know, that's what I did and it cost me about €60 or so (gave it to the store that sold the machine, an authorized service center). I don't like paying for something I can do by myself

[Eug]

Originally Posted by zykron 

My guideline is whatever matches the amount of RAM you have in the machine.

Since I have 1.25 GB in my iMac, I need to have at least 1.25 GB free at all times.

That makes some sense, but it doesn't give you any reom to maneuver. One batch of photos from my camera can be that much alone. And a DVD rip might be close to 8 GB.

Originally Posted by davidbk1 

It actually starts telling you to free space up. I think that happens around 300 MB free, but IMO you should never get there. I use 10% as a rule to keep the machine running fast.

Well, 10% is probably too much in my case. With a 500 GB (or 465 real GB), that means 46 GB free space. I think I'll start to really worry when I get below 20 GB. But then again, your rule of thumb may jive with that, since that partition only has 185 GB.

Come to think of it, I only have 14 GB left on my iBook G4 800. Works fine. However, I basically do nothing on that machine except surf, show JPEGs, and give Keynote/PowerPoint presentations, etc.

With my iMac (which is the machine I'm worried about), I have a fair amount of stuff running in the background, and often have a bunch of apps in the foreground as well. I have 3 GB in the thing, and still sometimes end up paging out to disk.

I can't wait until the Nehalem iMacs come out. 1 TB storage and 4-8 GB RAM would be perfect.

[cmeisenzahl]

"I think it's about 3 gigs. I'd try to keep at least 5 gigs free at all times."

I'm w/ Seanc on this.