I understand and use scratch disks. I have 2-2GB partitions set aside on a 2nd HD, and the balance of that same drive (strictly data drive) as a 3rd scratch disk. I work with many files that start out about 100mb and quickly grow to 1-2gb with layers.
My question is this: I reformating up an ibook for location photography, and am installing OS10.3, PhotoshopCS, It has just a single 20GB HD. Is there any advantage to partitioning the HD and setting up a separate partition as a scratch disk, vs just letting Photoshop assign the whole main drive as the default scratch disk? I also had a external 60GB Firewire HD (Buslink data banker) that I’ll bring along to back up my files from the ibook. Would there be and advantage to using is as the scratch disk?
There would be no speed gain by partitioning the one drive; it still has only one set of read/write heads anyway.
Some users like to do it anyway in order to lessen the impact of disk fragmentation, but with only 20 GB of HD space and working on 1 GB files, the entire disk will end up being used as scratch in any event.
Under that scenario, I’d definitely consider using the FW drive as well.
Apart from that, what Ramón said. I partitioned my PowerBook internal drive and and actually lost a tiny, tiny amount of performance, but it means that Photoshop won’t go trampling over my data should something nasty happen. (Not that I’m suggesting it would, after all there’s just as much chance that Mac OS X will trample over my data with its swap file, but I perceive a slight risk reduction.)
The file sizes will be much smaller on location, as I will be capturing raw un-processed files from a digital back. The file size may only get to about 66mb each on location, The major work would be done on the G5 back at the studio.
I still like the idea of defrag. the partition as the raw files will be pulled off after each shoot. So there will be a lot of files moving "on" and "off" the drive. I was thinking making a 7GB partition for the OS and Applications, and 13GB for the data files and scratch disk combined. If I find I’m running short of disk space I could add a partition the FW drive, or just assign it as the primary scratch disk and relaunch CS to free up data space on the 13GB partition.
7 GB is a bit light for the OS in my opinion; remember that you need to allow space for Mac OS X’s swap file, and for burning CDs if you use Disc Burner. As an example, currently my Applications folder is 5.5 GB, System is 1.2 GB and Library is 0.5 GB. The Users folder is currently weighing in at 9 GB but it wouldn’t be difficult to stick that on another drive if I felt inclined to do so.
Graham I hear what your saying about size for the OS & Apps. If the OS needs more room for its swap file, will it use some of the 13B on the other partition, or does it only look at the partition its OS is on? Same question- if I choose to burn the final files for back up at the location?
My users folder should be pretty much empty as the 2nd partition(13GB) will be the Client Folder, it will hold the final captures from the shoot.
This system will only be used for location photography, and files pulled off once were back at the studio.
I don’t know about the OS swap file location, so I can’t help you there. The Disc Burner definitely uses the start up disk, and if you don’t have enough room it simply won’t work, because Disc Burner works by creating a disk image the same size as the medium you are writing to. But you can solve that by using Toast instead.
In the end the partitioning scheme has to be up to you. The great thing about partitioning is that you end up with a well organised system. The bad thing about partitioning is that it forces you to predict your future requirements, which is not an easy thing to do at all.
20 GB is quite small for pro images work and OS X. I have a Mac with a 7 GB main partition <sigh>, and 7 GB is definitely too small, because many apps plus the OS insist on using the OS partition. I suggest your OSX/apps drive be 15 GB and use a 4-5 GB partition for scratch #1 with the 15 GB OSX partition as scratch #2.
