Author Topic: PM using lots of CPU  (Read 1796 times)

Offline chardinej

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PM using lots of CPU
« on: September 29, 2012, 04:49:53 AM »
Sorry if this has been asked somewhere here before.

I am running the latest versions of PM and Mac OS X Mountain Lion.

If I open up a large folder of images, containing say a few 1000, PM starts to really work my computer. The fan starts blowing and Activity Monitor says that 175% of the cores are being used. Two questions:

1. What is PM doing behind the scenes?
2. How to I stop it from behaving this way?

I suspect the cause is that I have High quality thumbnails set in the Contact sheet and I have bigger thumbnails than the default ones. Am I right? Is PM really rendering and cacheing thumbs for images in a folder that I am not even viewing because they are off the page?
John

MacBook Air i5/10.8 (Mountain Lion); PM 5 latest build

Offline Kirk Baker

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Re: PM using lots of CPU
« Reply #1 on: September 29, 2012, 08:17:06 AM »
Sorry if this has been asked somewhere here before.

I am running the latest versions of PM and Mac OS X Mountain Lion.

If I open up a large folder of images, containing say a few 1000, PM starts to really work my computer. The fan starts blowing and Activity Monitor says that 175% of the cores are being used. Two questions:

1. What is PM doing behind the scenes?
2. How to I stop it from behaving this way?

I suspect the cause is that I have High quality thumbnails set in the Contact sheet and I have bigger thumbnails than the default ones. Am I right? Is PM really rendering and cacheing thumbs for images in a folder that I am not even viewing because they are off the page?

Of course it is generating thumbnails that you haven't scrolled to yet.  That said, the next build of PM 5 has some performance improvements for laptops running Mountain Lion.

PM 5 is always going to use as much CPU as it can in order to get the job done as quickly as it can and then it should go idle when it completes.  Usage will of course go up as you scroll around and cached thumbnails or previews are loaded from the disk cache, but the CPU utilization should not go as high during this phase.  When new images are encountered like when you open up another contact sheet then CPU utilization will rise again.

How do you stop it?  You can't.  If we did it any other way then PM would be as slow as the rest of the browsers on the market.

-Kirk

Offline chardinej

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Re: PM using lots of CPU
« Reply #2 on: September 29, 2012, 09:11:00 AM »
Thanks Kirk. I understand. But as it seems to take no time at all (= virtually instant) to render the thumbs on a single page, why not just do this on demand as you scroll through your images? I may go to a folder containing 2000 images looking for one image. I don't need PM wasting CPU cycles rendering and caching images that I will never look at in that session. Why not make "Render/cache a single page of thumbs at a time" an option?
John

MacBook Air i5/10.8 (Mountain Lion); PM 5 latest build

Offline Kirk Baker

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Re: PM using lots of CPU
« Reply #3 on: September 29, 2012, 09:48:14 AM »
Thanks Kirk. I understand. But as it seems to take no time at all (= virtually instant) to render the thumbs on a single page, why not just do this on demand as you scroll through your images? I may go to a folder containing 2000 images looking for one image. I don't need PM wasting CPU cycles rendering and caching images that I will never look at in that session. Why not make "Render/cache a single page of thumbs at a time" an option?

Sorry.  We're just not going to do that.  The reason it seems like it is taking no time at all to generate those images is because of the way we cache images.  If we changed things in the caching system you would no longer observe the behavior you're seeing.

-Kirk