I’ve been seeing a lot of differing opinions online regarding the advantages of SSD vs HDD for image storage. Running synthetic benchmarks on the 3 different types shows a Sata SSD to be around 5 x faster than a HDD, and an NVME SSD to be around 5x faster than the Sata SSD. I ran some image stacking tests in PS to see if the synthetic benchmark results translate into real-world performance gains.

For the tests I used a PC running Windows 10 with an Intel 8700k CPU overclocked to 5.2ghz, 32gb DDR4 3200mhz RAM, RTX 2080ti. The storage devices used were Seagate Barracuda 8tb 5400RPM HDD, Seagate Barracuda 2tb 7200 RPM HDD, Samsung 860 EVO 1tb Sata SSD and Samsung 970 EVO 1tb NVME SSD.

I used Adobe Bridge to select 50x 14bit RAW files from a D850, then went to Tools>Photoshop>Load Into Photoshop Layers. (this is a big part of my startrails stacking workflow, and can be completed in RAM, without going to the scratch disk)

The results:

Seagate Barracuda 8tb 5400RPM: 2:13

Seagate Barracuda 2tb 7200 RPM: 2:05

Samsung 860 EVO 1tb: 2:04

Samsung 970 EVO 1tb: 2:02

I was a bit surprised by these results, i did not expect the mechanical hard drives to do that well.

While there are slight differences between the different drives, they are nowhere near being inline with the read time benchmarks. Photoshop stacking performance is not bottle necked by storage speed, but the processing involved in opening the image. With lower resolution/bit depth images the results might change as the processing time will be reduced, I didn’t bother testing that as I always use the highest quality image settings my camera is capable of.

Depending on your power management setting in Windows, a mechanical drive might spin down if it’s been idle for some time to save power, when opening a file from the drive there will be a delay while the drive spins back up (control panel>power options>change plan settings>change advanced settings>turn off hard disk after Xminutes).

Keep in mind that these tests are only relevant to Photoshop image stacking, for things such as Photoshop scratch disk and transferring files from a memory card an SSD will have large performance advantages over a HDD.