PS Under Utilization of CPU/Resources

[johnfr80504]

I am looking for advice on how to get PS to better utilize the CPU and resources.

As a Wall Mural Landscape photographer I am normally working with very large images. These are always in 16 bit mode. For example the one I am working on presently is 4.2 Gigapixels measuring 128,228 x 33530 pixels. Obviously a very large file.

I have the Windows Resource Monitor running and am noting that PS rarely exceeds 12% CPU utilization no matter what I am doing. I have very few other applications running so there is plenty of CPU cores and resources available.

One typical example (with a large image as descibed above) of what I am talking about is a case where I have created 2-4 layers with masks generated by TK Actions 8 plugin. I will then Flatten the image which on the large file mentioned may take upwards of 8-10 minutes. All the time during the Flatten operation, the CPU utilization is 8% - 12% at the most. Only 2-3 of the 12 cores of the CPU show any increase in usage. The GPU useage is virtuall 0% for a Flatten operation. I see no read or write operations going on with any of the storage devices. It seems that PS is under utilizing the resources I have avaliable for it.

I am using the latest PS 24.1.0 release

Windows 10 Pro with latest updates.

Device name john-pc
Processor Intel(R) Core(TM) i7-6800K CPU @ 3.40GHz 3.40 GHz
Installed RAM 128 GB DDR4 2400
EVGA GTX-970 GPU

2 Scratch M2 type SSD's  1TB & 2TB

Primary drive is also 1TB SSD with at least 40% unused space.

I have PS preferences set to use 80% of available memory, Optimize for Huge Pixel Dimensions, Cache Levels at 6 and Cache Tile size set to 1028K, Multithreaded compositing is checked.

Any suggestions as to how to get PS to better utilize the CPU and resources?

[Bojan Živković]

Without engineers I can only suggest larger separate scratch disk which can possibly speed up operations. Maybe some engineer who code apllication can provide better insight how deed is done and which resources are in use for operations and calculations. I am not surprised that GPU is not used to flatten image. Also not surprised that GPU is at 0% because nothing visually changed on screen while calculating. They are utilizing GPU for newer filters but keep in mind that some functions are old and unchanged for many years.

[D Fosse]

This will be I/O limited, not CPU limited. Most of the time, the CPU will be waiting for data.

More and faster disks is the only thing that could help. 10 TB scratch disk, PCIe 4 interface NVMe at a (nominal) speed of 8000MB/sec. Then maybe.

I can't help but wonder. Are you assuming 300 ppi at actual size? You don't need that. I can't think of any realistic scenario where 130 000 pixels is really needed, unless you're NASA or google earth.

[johnfr80504]

Yes, I am assuming 300 ppi at actual size. I specialize in ultra large wall mural photography.. I sell to customers that are looking to fill walls that are very large. For example I recently licensed a mural of one of my photos that was 11 ft. x 75 ft. I supplied it as a 2.67 gigapixel,150 ppi image measuring 19,800 x 135,000 Pixels. Here is my work:Fine Art Gigapixel Wall Mural Photography 

[D Fosse]

Take a look at a standard computer screen at a typical native resolution of 90-110 ppi. Do you see pixels? Does it not look sharp?

300 ppi for print is a myth. It's a theoretical upper limit for books and magazines, to be seen from less than arm's length, and printed with a standard halftone screen of 150 lines per inch. Above 300 ppi, no improvement is even theoretically possible - it can still be razor sharp at lower ppi, but 2x line screen frequency means you can no longer discern individual pixels. That's how the limit is defined, and in reality it's a limit for smoothness, not sharpness.

And then this upper limit for small format close viewing became widely misunderstood to be a general lower limit at any reproduction size and viewing distance.

The bigger it is, the farther away it will be seen from, so ppi requirement drops rapidly. A large wall-sized banner can be 10 ppi and look perfectly sharp.

A good general rule of thumb is that if the image exceeds 20 000 pixels or so long side, you should think really hard about whether it's really needed. In most cases it isn't. 20 000 pixels is still a massive file, even a state-of-the-art medium format camera (at the price of a medium sized car) will only deliver about half of that.

130 000 pixels is NASA resolution.

[PECourtejoie]

Hi, what is the typical viewing distance of your works?

About the issue at hand, please post the contents of Photoshop's Help>System Info... menu, so that we get to know the settings chosen for compositing.
If your post disappears, do not repost it, as it might need to be approved by a moderator. As an alternative you can save it to a .txt file on your computer and attach it on your answer via the forum. (attachments do not post from e-mail)

[johnfr80504]

Viewing distance can be as close as 18 inches or less. Viewer should be able to walk up to the mural and stand virtuall toe to wall from the mural.  My goal is to have wall murals that are as sharp and clear as any 8 x 10 photograph. For example, the file I am working on that caused me to make the original post, is a mural 33,530 x 128,228 pixels, 111 x 427 inches. In the process of editing the image I found a Big Horn Sheep laying on one of the points. See the attached file "Big Horn Ewe.ppg". This is a 2.6" h x 4.5" w area of the overall image. I want my view to be able to readily spot this animal in the printed wall mural and be able to recognize that it is a Big Horn Sheep. 

My work is not intended to be roadside bill boards that are, as D Fosse stated, typically printed at 10 ppi with the expected viewing distance of 100's of feet away.

I have also attached the System Info you requested as a text file

Thanks