How to set up an optimal scratch disk?

[davidkas]

Hey guys. Having some trouble trying to research this online, so I figured I may as well ask here.

I want to set up the best possible scratch disk solution for photo-editing. Now, here's the thing. I use Lightroom and Photoshop. With Lightroom, I keep all my photos organized into catalogs, and the catalogs are all on an external drive - I always have the drive with me when editing. However, I also use the same drive as my scratch disk for Photoshop.

Now this current set-up makes me a little nervous, since I've heard that using a drive as a scratch disk wears it down much, much faster. However, I don't want to use 2 different drives - one as my catalog drive for Lr, and the other as a scratch drive for Ps. Not very efficient nor portable.

Currently, this is all set up to work with my older MBP through firewire 800. Just ordered a brand new MacBook Air, maxed out. Will finally get to try out USB 3.0 for a change. With it, I want a better scratch disk solution that is affordable.

Right now, I'm thinking I should get a USB 3.0 enclosure with a 7200rpm drive, 500gb or more. Then break it into two partitions, one for my catalogs, the other for scratch disk. Is that a good idea? Will using one partition as a scratch disk put more wear on the drive as a whole?

Or would an SSD be a better option? After all, then I won't have to worry about wear and tear on the drive as much. But is 7200 fast enough that I won't notice the difference, or is USB 3.0 still the bottleneck when it comes to read/write speeds between a 7200hdd and an SSD?

Or, should I get a smaller SSD exclusively for scratch disk, and a separate drive for cataloging? As annoying as it would be to have to use 2 drives all the time, if it's the best solution, I may go with it.

Thanks for your time!

 

[steveash]

Once you have an SSD drive for system and apps then you may not need an external scratch disk. As long as there is sufficient space on the SSD this will be considerably faster than an external HD. Being solid state it runs at a speed close to that of normal memory.

If you need a bigger scratch disk than you have internal space for the fastest option would be a thunderbolt SSD. From what I've read, a 7200 HD will give a similar apparent speed as an SSD through a USB 3 port.

Partitioning your external storage drive will give the slowest result as you will be writing files and cache to the same drive at the same time. In my experience drives get out of date before they ware out but it's always good to have a backup of important work.

My dream setup would be a the new Drobo Mini full of SSD drives but that is expensive and Drobo don't have the best reputation.