HD more than half full.....

[treeman]

is it time to dump some stuff on to another external HD?

I was told some time ago, (so now may not be relevant) that for optimum performance, you should not let your HD get more than 25% full. Something about it has to start writing to the outer edges of the drive so will be slower :shrug:

 

[neil_g]

what? more than 25% what a waste of space..

you should never let the drive drop BELOW 10% free disk space before performance become effected..

 

[treeman]

what? more than 25% what a waste of space..

Well I did think it was a little extravagant!

I'm going to look into it further though as my 10 month old imac is definitely running slower when running PS and LR, now with only 40% space remaining on the 1TB HD.

I'm also going to do some tweaking of PS and LR settings to make sure I'm running it as sleek as possible first.

 

[markrichardson]

Read-write times will get gradually slower as the drive is filled up. (There is a fairly simple physical reason for this - data will be written starting with the closest sectors of the drive. While everything is in the closest sectors, there is less physical movement needed and therefore read-write times are shorter. As the more distant sectors of the drive begin to be used, read-write times will increase). Technically I suspect that drive performance would be worse at 40% full than 25% full, but I doubt it would be noticeable difference. From what I've read around 70-80% full is the point at which on performance decreases usually become evident on modern drives.

There has been some interesting research done on optimising performance of drives by ensuring that regularly accessed information is stored in the locations with the quickest access times. The most interesting development in my mind (at least until SSD are cheap enough to be mainstream) is hybrid drives like the Momentus XT, which gets around some of the performance issues of drives by having a small embedded flash drive which is automatically updated to store the most commonly accessed data. I found that after about a week of using one in my MBP, opening Lightroom and Photoshop takes about one third of the time that it did previously.

 

[gman]

is it time to dump some stuff on to another external HD?

I was told some time ago, (so now may not be relevant) that for optimum performance, you should not let your HD get more than 25% full. Something about it has to start writing to the outer edges of the drive so will be slower :shrug:

The outer edges of the drive are faster and a good defrag program will allow you to shove the most frequently used files to the outside of the disk. This is why disk partitioning isn't always a good thing because each partition will get nearer the inner and slower part of the drive.

I think 25% is a bit OTT and if it's for storage purposes then I'd fill it easily to 75% as the speed difference is not going to be all that noticable. If it's the OS drive then you probably will notice a bit of a difference.

I think the reason for leaving a decent amount of space is because files expand when opened and also when defragging the system needs space on the HD for moving things about.

Do you reckon the difference in seek time of a few milliseconds is going to make a loss or cause problems for you?

 

[Chappers]

Images take up huge amounts of space, that's why I keep all mine on external drives. You might want to consider migrating yours to one of those. I'd opt for a fire wire drive if you can as it will be quicker than a USB one

 

[neil_g]

I'd opt for a fire wire drive if you can as it will be quicker than a USB one

not in all situations. concider eSata or USB3 if you have the means.

 

[treeman]

Images take up huge amounts of space, that's why I keep all mine on external drives. You might want to consider migrating yours to one of those. I'd opt for a fire wire drive if you can as it will be quicker than a USB one

I think thats what I might do. I've already got one Ext HD attached, which I back up images to. I think I read somewhere, that you can daisy chain HD's together :shrug:

 

[neil_g]

I think I read somewhere, that you can daisy chain HD's together :shrug:

yes with firewire and if the drive has the capability

 

[Chappers]

yes with firewire and if the drive has the capability

Neil

Yes did consider that as a suggestion, but as the OP has an iMac then he limited to what peripherals he can use

 

[morsing]

The "Don't fill it up rule" isn't to do with the physcal disk drive, it's because file systems slow down when they are trying to allocate space to files. Depending on file system type, going over 80% will start to significantly slow down writes.

It's only writes slowing it btw, reads will be constant.

It's true disk drive are faster at the beginning of the disk but it's hardly anything you would notice.

 

[neil_g]

Neil

Yes did consider that as a suggestion, but as the OP has an iMac then he limited to what peripherals he can use

my bad, missed the imac bit

 

[onomatopoeia]

is it time to dump some stuff on to another external HD?

I was told some time ago, (so now may not be relevant) that for optimum performance, you should not let your HD get more than 25% full. Something about it has to start writing to the outer edges of the drive so will be slower :shrug:

I don't know what file system you are using, but unless it's something of the quality of FAT16 the above is untrue, in fact even with FAT16 you need to fill up a good deal more than 25% of the disk. NTFS, ext2, ext3 only start to have performance issues above 90% full.

With external drives you run the risk of being limited by the speed of the connection to the computer rather than the speed of the drive or the filesystem.

 

[Raymond Lin]

One of my back up drive is 95% full

But i tend to only install OS and Apps in the internal HD so its never more than 25% full anyway. Keep data and OS separate, run back ups on the data and you wull be fine.