100% CPU load when saving PNG

[gmenzel]

With one of the last PS updates (not sure which, unfortunately), the behavior when saving files PNG format changed. For instance, when saving a flat 8000x8000px RGB8 image with maximum compression, Photoshop now puts 100% load on ALL 28 cores of my XEON workstation for about 30 seconds.

I don't mind saving to PNG taking some time, so I would rather not have it lock up my machine like that.

[Mohit Goyal]

Hi gmenzel,

We're really sorry for all the hassle. Could you please deselect the GPU from the Photoshop preferences, restart Photoshop and let us know if that helps.

Regards,

Mohit

[gmenzel]

Thanks for the quick response, Mohit!

That's not it, unfortunately. I had to deactivate this options already for other reasons.

[Test Screen Name]

Did it used to take much longer (10 minutes maybe) on one core?

[gmenzel]

No, it didn't take much longer - if at all. I don't have numbers to compare, but it feels about the same.

[PECourtejoie]

Hello, the png-saving code code has changed indeed in one of the lasts major  versions, I have to search more info...

[PECourtejoie]

Hello, in October 2017: better compression for PNG  New features summary | January 2018 and October 2017 releases of Photoshop CC

Is the weights of PNG files you saved the same in CC2014, Cc2018?

[gmenzel]

Thanks for the info!

Yes, specs of files are the same. Hardware of the workstation also remained unchanged. I'm happy to provide more details, if needed.

[Test Screen Name]

I'm guessing this is exactly what it is supposed to do. Using 100% of all cores is the holy grail of any programmer, and Adobe have some smart multicore programmers. This should not be any sort of performance hit: running at 100% is what an app does if nobody else needs CPU, and it's the job of the system to share it fairly.

[gmenzel]

If this is indeed the intended behavior, then at least saving a PNG should not take more than a couple of seconds. But it takes about as long as it did when running single-threaded.

As for load-balancing, even within Photoshop itself the UI response gets unusably slow while saving is in progress. In the past I was able to continue work on other documents.

[Test Screen Name]

Hmm, maybe it always used the cores, but the UI being unresponsive is a new issue. Just a thought.

Another possibility: that the "better" compression mentioned is much more computationally expensive. Are there any controls in Save-as-PNG for you?

[WickesCollective]

I should state that I am also suddenly having this issue! 32gb of RAM and an i7 8700 processor and my entire system gets locked up when saving a PNG. It relaxes some if I select a lower compression to save. It's interesting - PSDs are almost instant and doesn't touch my system and yet a single layer PNG file freezes up my whole system! Was watching a movie and the system literally had a spasm and I was expecting it to blue screen!

Anxiously waiting for some replies for a possible fix for this. You're not alone, OP!

[gmenzel]

Good to hear it's not just me. I hope a staffer escalated the issue and a developer will investigate the problem. Although it would be nice to have this confirmed... Mohit?

[gmenzel]

So I'll just wait for the next update and hope for the best?

[JayB_LAHC]

Looks like it's been 5 years and Adobe doesn't care about this problem. I'm experiencing it now after an update.

[MK_Berlin]

I am experiencing exactly the same issue for quite some time, using a MacBook Pro 15" from this year with 16GB. Saving PNGs in Photoshop gets the fan running as if I'm rendering god knows what kinda 3D material on video. I wouldn't notice the truly excessive CPU usage of doing something as banal as saving PNGs was it not for that noise howl of the fan.

I use iStat Menus to keep track of my system, and it just told me Photoshop was taking up 1166% of active processes. That's absolutely gigantic. I've hit the 800% region a couple of times today. Normal apps shouldn't go much over 100%, ever.

[MuhammadAzzaidie]

It's 2022 and I'm still on the same boat, nvme SSD, rtx 2080, ryzen 7 2700x, 32gb ram, saving a 4k (4096*4096@72dpi) single layer 8-bit texture as png takes upwards of 5 minutes of 99% cpu usage, bugs down everything 

[JayB_LAHC]

I've just encountered the same issue, ran updates recently which I hadn't done in a while and using even the latest Photoshop saving a PNG of any size shoots every core on my computer up to 100% and takes forever to save. This is horrible quality control. Nothing is different about my computer and the only thing I did was update Photoshop.