Using Solid State Drives (SSD) for Photoshop CS4 Scratch
The diglloydHuge benchmark causes Photoshop CS4 to generate a ~56GB scratch file which means that the CPU speed or number of CPU cores has only a modest influence.
My previous best-performing setup for Photoshop CS4 has been a 4-drive RAID-0 stripe of the Hitachi 7K2000 hard drive, capable of ~500MB/sec sustained throughput. But it’s about more than that— there are latency and other performance issues involved, and this is unequivocal in the timed results.
The dual-SSD setup dramatically reduces the time as compared to the 4-drive Hitachi 7K2000 setup. However, results using 24GB memory (twice as much) improve to nearly the same speed as the dual SSD setup, so this shows that memory counts, big time. You best bet for a big job like this is 24GB or more of memory (up to 64GB in an 8-core machine), along with dedicated dual SSDs t reduce any contention during save/open off the main volume.
For truly enormous jobs, the quad-SSD setup cuts another big chunk of the time down. In this test, there is no benefit to using two eSATA cards over just one card for a quad-SSD setup, but there is benefit to using an eSATA card, since the Mac Pro Nehalem’s internal SATA ports throttle performance with four of these SSDs.
The optimal number of SSDs appear to be three (3). While small gains are possible with four drives, this is likely to be of little significance for most jobs. Two (2) drives looks to be a price/performance sweet-spot.
Not just any SSD will do
Just as important, internal SSD fragmentation plagues some SSDs brands, at least as of early 2010. Choose your SSD carefully, and please see the other test results in my review of the OWC Mercury Extreme.
For Photoshop scratch purposes, the 50GB model is just fine, no need to use the 100GB or 200GB models unless the largest scratch usage would approach the capacity.
With monster Photoshop jobs to run, a 2-drive RAID-0 stripe of the OWC Mercury Extreme SSD offers the potential for vastly improved performance, even over a fast 4-drive striped hard drive setup.
Please see the review of the OWC Mercury Extreme for details on hardware configuration.