Saving Photoshop PSD Files

[Preston]

There was a lively discussion at Nature Photographers Network-Digital Imaging Forum regarding very long 'save' times for Photoshop PSD files. One member there was frustrated that his save times for layered 500MB PSD files were taking up to 30s. These times were observed on a Puget Genisis with an i7-3.2 GHz, 16GB RAM, SSD main drive, and SSD PS scratch disk. I experienced similar times on my Puget Obsidian i5-3.3 Ghz, 16GB RAM, WD Blue HD's. Both machines running Win7-64 bit and Photoshop CS5.

We suggested system checks and tweaks to Photoshop--little or no change in the results. Both Puget machines are working perfectly, so what was going on, here?

One of the NPNers did some research and discovered that CS5 uses an algorithm that results in more accurate image files, but increases 'save' time. How about that!

If the save times for PSD files bother you, you can save them as uncompressed TIFF files. The file size will be larger, but save times are significantly reduced.

Hopefully, Adobe will tweak the algorithm in PSCS6 so that faster saves are possible.

--Preston

PS: My Puget computer is 'da bomb'!

[PCC-William]

Very interesting! It sounds like the delay during the save is CPU time spent compressing the image in a low-loss way, and the roughly similar times make sense since you both have quad-core CPUs at similar clock speeds. It can't be the drive speed, if saving without compression takes a shorter time (since the file size would actually be larger that way).

Something I would be curious about: during the PSD save, are all of your CPU cores working hard? If so, that definitely confirms that it is just compressing the data. If only one core is working at nearly full (or all cores at about 25%) then it may also indicate that is the bottleneck, but it could also show that the compression routine is not multi-threaded; that would give some hope that they could improve upon it in the future.

[Lance Warley]

Only one CPU core was working at 75% or more. Another two CPU's were doing something at less than 25%, or lower. The others were doing nothing.

It's an easy test for anyone to do. I just duplicate a Background layer 5 times with a Canon 7D file to create a 500 MB file. Then I watch the Resource Monitor when I do a Save.

I think the news about saving as Tif will help thousands of people, because the thousands who already save as Tif probably think that's what everyone else does.

[Preston]

Lance,

Thanks for your comment, and welcome to the Puget Systems forum!

William,

Thanks for your comment on this. I'll take a look at the CPU activity later today to see if I obtain results similar to what Lance reported.

Just a couple of notes: I am running the 64-bit version of Photoshop but I don't know if that's part of the equation. I was using TIFF for my master files (edited from scans of 4x5 film), but the files sizes were rediculously large (some over 3GB!), so I reverted to PSD. The longer save times don't bother me.

--Preston