Hard drive safety space
 

I've got a 500gb external hard drive that I'm filling up with HDV footage. How much free disk space should I leave? Is 50gb free space enough? Or can I even have a smaller amount of blank drive? Will it slow down the hard drive as I put more on? Obviously the Final Cut program itsself is on my main internal drive--also 500 gb (btw, with so much hard drive there, could I possible use a 100 or so gb of my main internal drive without slowing it down?)
Thanks all if you have any info,
Happy Roshashana!

There is no such thing as harddrive safety space (*) unless you want to leave
some room for putting more stuff on there if you need to.

The harddrive itself will not slow down depending on how much information you
put on there. However, since the data is on discs which will have different rotating
speeds at the inner and outer tracks (due to physics) the last part of the drive
will be slower than the first part.

I'm not sure I understand your 100 GB question at the end.

(*): the drive the Operating System sits on (normally) needs temporary space
to do the jobs it needs to do. So in that case it is wise to leave a bit of head
room available.

Sweet! I've never had a second hard drive before so I wanted to make sure I didn't screw it up--I'll cram that sucker up to 490 gbs then! Thanks, mon frier...

Betsy,

I'm a little troubled by Rob's assertion that you can completely fill up your external drive. I'm not entirely sure that this is true.

I have always been told that you should leave at least 15-10% free for optimum read/write speed.

That's what I and everyone I know do, anyway. But perhaps we're all wrong and this only applies to the system drive... but somehow I don't think so.

Best

Harry

I believe the issue has to do with fragmentation, and that can slow down a drive as it fills us. When you write a file to your disk it is stored in chunks called sectors. For the fastest access times you want those sectors to be contiguous - right next to each other. As a drive fills up the empty sectors may be scattered all over the drive, on different parts of different tracks. So if you write a large file it will be split up into lots of little pieces in different places, and the drive will have to spin more revolutions between accessing each of these pieces. The problem gets worse as you delete files and replace them with new ones, leaving small chunks of empty space all over the place.

Video files tend to be large, so the number of files on your external drive will be much less than your internal boot drive, and that helps to keep fragmentation down. Macs run on unix, which is an operating system that contains thousands (probably tens of thousands) of little files right out of the box. The internal drive is likely to be fragmented much more than an external media drive due to this, and performance will probably be worse on the internal. It may be "good enough" for video, but it's generally considered bad practice to put your video files on the startup drive unless you don't have any other options. Also realize that the operating system and your other programs are constantly reading and writing to the internal drive and that can impact performance if you put your video files there.

Pesonally I believe in keeping a bit of free space on an external drive. When it starts to fill up and I'm ready to begin a new project, I reformat the external drive and start from scratch. This clears out any existing fragmentation and insures top performance. Of course, you need to have some strategy for backing up and archiving things on the external drive, but that's another topic.

Harry: as I indicated a harddrive will get slower the more close you get to the
end. It's not a problem, it just becomes a tad slower. I've filled up numerous
drives to the last megabyte without any problem (it's just a bit slower).

For normal day to day operations it is a good thing to keep some free space.
Most importantly so you have some if you need it. In some applications you
may not want to write to the last part because the speed will be slower, but
that's mainly for high resolution / framerate work and should not be a problem
for DV / HDV since these have fairly low bitrates.