Scratch Disks and Photo Storage

[steve_c9]

<p>I have Photoshop CS4 on internal hard drive C, half full, with the OS and everything else.<br>

And I've just installed a second internal hard drive, E, to use as a scratch disk.<br>

Both are 500 GB, 7200 rpm.<br>

For the most speed, should I store the photos I'll be adjusting, batch processing, and photomerging on the Photoshop drive © or scratch disk drive (E)?<br>

(XP, 3 MB RAM.)</p>

 

[William Kahn]

<p>I have a similar setup, except I partitioned the second drive into drive F, 340 GB for photo files; and Drive G, 120 GB for scratch disk. Works fine...</p>

[martin-s]

<p>A separate scratch disk only makes sense when used as scratch space <strong>exclusively</strong>. Any other activity that accesses the disk will reduce its performance as scratch space.</p>

<p>Partitioning it doesn't help since it's still the same <strong>physical</strong> volume.</p>

[William Kahn]

<p>"Partitioning it doesn't help since it's still the same <strong>physical</strong> volume."</p>

<p>That may be true if you partition the main "C" drive, which is constantly accessed by other processes. However, partitioning a second hard drive into scratch disk + photo file storage reduces that level of activitity significantly. After I open a photo file, there is no activity on that partition whilie I'm editing the image until I do something that alters the file (save, remane, etc.). Even if there is some activity on the file partition generated by another process (such as anti-virus software), that level is exactly what you would experience on any drive, dedicated as a scratch disk or not; and again, that level of activity is cartainly less that you have on the computer's main drive... </p>

[matt_g3]

<p>SSD for the OS <em>only</em>.<br />1TB drive for data <em>only</em>.<br />2 160GB drives in a striped RAID for scratch <em>only</em>.<br /> BOOM!</p>

[howard_owen]

<p>FWIW, I read that photos (current working set) and Scratch should not share the same drive, regardless of partition schemes. I've not done any benchmark testing to verify this since I've no trouble keeping mine separated (4 drives in my imaging station). With a limited number of drives, choices and compromises have to be made.</p>

<p>If you have your images and Scratch on the same drive, you might take a performance hit during file Open and Save operations. I doubt that it will be too significant, but you can always test it and see.</p>

 

[mike_earussi1]

<p>Ram is much faster than any hard drive (except maybe for SSD). If you're forcing Photoshop to use a scratch disk then you don't have enough ram. Better to spend money on more ram in the first place so it doesn't need to access a scratch disk than to waste money on another drive just for that purpose.</p>

[martin-s]

<p>What Mike said. Also see <a href="http://help.adobe.com/en_US/photoshop/cs/using/WSfd1234e1c4b69f30ea53e41001031ab64-748aa.html">Adobe Photoshop – Memory and performance</a>:</p>

<p>The following guidelines can help you assign scratch disks:</p>

<ul>

<li>For best performance, scratch disks should be on a different drive than any large files you are editing.</li>

<li>Scratch disks should be on a different drive than the one your operating system uses for virtual memory.</li>

<li>RAID disks/disk arrays are good choices for dedicated scratch disk volumes.</li>

<li>Drives with scratch disks should be defragmented regularly.</li>

</ul>

[steve_c9]

<p>Thanks, everyone. I'm going to test it first, but I think I'll go with the photos on the C drive and then store them, once they're done, on the second drive, like William said, and that way I can keep it all defragmented.</p>

<p>And Mike, I got 3 GB RAM, but Photoshop in XP can use only 4 GB, and I figured better to spend money on a second hard drive, to get all my photos off CDs, which I can then move to a new computer when that time comes.</p>