Photoshop PSD files save speed benchmarks
Adobe Photoshop is very slow at saving .PSD and .PSB files, while it’s now done in the background i’ve found that annoying because I can’t close or save another version of the file at the same time.
I was curious to see what was the bottleneck so I made some benchmarks.
STORAGE
My first test was to see if the storage speed make any difference, to test that I used a variety of options from one of the fastest NVME SSD to a SD memory card in a cheap adapter. To make any difference more evident the file saved was a very large : 5740x5800px with 15 objects and 20 layers for a total of 4,4 Go in a PSB format.
| Drive | Theoretical speed | Time to save |
|---|---|---|
| Samsung 970 EVO | 2700 Mo/s | 4min 21s |
| Corsair P1 | 1800 Mo/s | 4min 21s |
| Crucial MX500 | 500 Mo/s | 4min 22s |
| Hard Drive ( NAS ) | 100 Mo/s | 4min 48s |
| Sandisk Extreme Pro | 80 Mo/s | 5min 15s |
The result is the same for all SSD drives, we start to see a small speed penalty when writing on the hard drive in a Network Attached Storage but it shouldn’t be noticable on a daily usage with smaller files. I don’t have a hard drive in my computer so i can’t test if it’s the spinning metal or the 1 gigabit network who is the bottleneck. I included an SD card for fun and yes, it’s slow.
CPU
If it’s not the storage maybe it’s the processor, since I made an update soon after testing the storage I tested this parameter using the same file and the same system :
| CPU | Characteristics | Time to save |
|---|---|---|
| AMD Ryzen 5 2600 | 6C/12T - 3.4Ghz | 4min 21s |
| AMD Ryzen 9 3900X | 12C/24T - 4.1Ghz | 3min 40s |
So it’s the CPU who is the bottleneck while I save my files with a 19% increase with the faster processor , but theses CPUs are vastly different in cores, technology and frequency, what can we learn more ?
If we look at their absolute processing power using Cinebench R15 scores we have theses results :
| CPU | Single Core | All Cores |
|---|---|---|
| AMD Ryzen 5 2600 | 163 | 1307 |
| AMD Ryzen 9 3900X | 213 | 3168 |
While the 3900X is 59% faster when we use all the cores of each CPUs, the difference is only 23% when we use only one of their cores wich is very close to the 19% difference in file save speed we saw earlier.
So the single most important factor in file save speed in Photoshop is donc the single core speed of the processor.
But why ?
PSD vs PSB vs TIF
The only practical difference between PSD ( PhotoShop Document ) and PSB ( PhotoShop Big ) files is the size limit, PSD are limited to 2GB while PSB are only constrained by a width and height of 300 000 pixels maximum. What is less know is that theses file formats uses lossless compression and this is an option we can toggle in the preferences of Photoshop.
TIF is another file format with support for layers and compression so we can test it as well.
Let’s test that :
I used a 5000px by 4000px pictures with 24 layers ( 6 objects and 18 layers ) to test if the file format has an impact.
| Format | Compression | Time to save | Size |
|---|---|---|---|
| PSD | yes | 50.4s | 1 190 498 Ko |
| PSB | yes | 50.7s | 1 190 498 Ko |
| PSB | no | 4.2s | 2 565 865 Ko |
| TIF | yes (zip) | 52.7s | 1 178 630 Ko |
| TIF | no | 7.4s | 2 561 138 Ko |
PSD and PSB both compressed are practicaly the same in file size and have the same save speed. TIF compressed with zip algorithm is very close both in size and speed.
When we don’t use compression with PSD and PSB the speed increase by more than 10X wich is impressive at the cost of a file almost twice bigger. TIF not compressed has almost the same file size but is marginaly slower to write.
With theses results I think PSB and PSB are using a more optimized zip compression than the old TIF, this processus is single threaded and that’s why they are so slow to save.