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speekez

macrumors 6502
Original poster
Nov 19, 2003
350
2
I'm using Leopard, CS3, Mac Pro with 4GB RAM. Would I be wise to set up a scratch disk located off of my main System/Apps disk. If so, what would be a smart scratch disk size to partition without creating a partition that is overkill in size. 5 GB? 10GB?

I work mostly with RAW files, PSDs, photography. Thanks.
 
I'd say it depends on the applications you use. Since you say you have 4 GB of RAM, I'd recommend the following:

If you're only using 1 application at a time that could benefit from the scratch disk, make it 10 GB.
If you're using multiple applications that could benefit simultaneously, increase this by 10 GB for every additional simultaneous app.

I would recommend 8 GB per app (twice the size of your RAM) but 10 GB just sounded better :p
 
Unless you're editing huge multi-GB psd files, I'd just install more RAM and not worry about configuring a scratch disk. With enough memory, neither the OS nor the Photoshop vmm (assuming it still uses one) will need to page out to disk.
 
Just to let ya know you the 4GB of ram should be plenty with PS3, I tried to max out mine and PS would only pull off 1.8GB with a 1.3GB file. There does seem to be a patch on adobe.com that fixes it so PS uses the extra ram for big files. I have also heard of making a Ramdrive to use as a scratch, however if the adobe patch does the same thing you can eliminate the ramdrive hogging space. I really dont worry about it because I rarely go bigger than a 21mp image with a couple raster layers (lots of Adj. layers though!) The 1.3GB PSB file was merely a test file enlarged to a gargantuan size.

I came close to paging out when I was working on my senior project with Photoshop, Indesign, Illustrator, Bridge, Safari, Mail, and iTunes (a very productive app :) ) running all at once.

As far as the partitioning, I have heard even if you have one disk, it gets better performance if you have a partition a section just for scratch so that its clear and unfragmented. If your looking for a fast disk setup you could put together a couple of drives and make a Raid 0 setup, try it without the raid scratch first, you might not need it. I am very happy with a 7200rpm scratch, very rare do I have to wait for a filter to apply.
 
Would you get a benefit from the partition vs. just using the boot partition as a scratch?

That's a q to anyone…

Of course. A scratch disk must be a separate drive because it has different heads and is capable of reading and writing independently of the drive with the application installed thus increasing performance.
 
Of course. A scratch disk must be a separate drive because it has different heads and is capable of reading and writing independently of the drive with the application installed thus increasing performance.

True, a blank partition on a second physical drive is the best solution, but Adam (quoted below) did hear correctly about about using one disk.

adamxz3 said:
As far as the partitioning, I have heard even if you have one disk, it gets better performance if you have a partition a section just for scratch so that its clear and unfragmented.

Normally I keep all my files on external disks and record audio to external firewire whenever possible, but sometimes I'm out in the field with my laptop, so I keep a couple extra partitions that I can erase at any time and voilà, a completely defragmented disk ready to use for recording. Even though I keep my startup drive as fragment free as possible, a blank partition will always be at least slightly less fragmented than another volume on the same physical disk and so also will perform a little faster.

Same goes for photoshop scratch disks or anything like that. A blank partition on a different physical disk is the best option, but if you only have one disk, a blank partition is always better than your startup volume.
 
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