Thumbnail generation is very slow with high CPU usage

If I open a folder with image files in it the thumbnails take quite a while to load as the CPU usage shoots up and my computer slows to a crawl. I had this problem once before and the solution was to exclude the folder with the thumbnail cache from being scanned by NOD32. The problem has returned and is getting worse and worse. First it started to slow when opening a folder of new images while DOpus built a cache but now it doesn't matter whether the thumbnails have been cached or not, I still have to wait a considerable time every time I open the folder the duration being realtive to the amount of images in that particular folder.
I've tried everything I can think of: Deleted the thumbnail cache (and checked the thumbnail directory was empty); I've tried it with no Anti-Virus running; I've tried all the different thumbnail preferences e.g. turning off high quality scaling, multiple threads etc., nothing makes a difference.

As a photographer I'm tearing my hair out here; I can't go on with DOpus any more and I don't want to go back to Windows Explorer.
I have a high spec PC including dual core processer, 2 gigs RAM and RAID striped HD which will run power hungry apps like photoshop with ease.
What's going on here? If anybody has any suggestions please please let me know

Try these FAQs:

[Crash, exit or high CPU when viewing certain directories)

[Opus uses 100% CPU / problems with AVI files)

Thanks Nudel but I've already seen [Crash, exit or high CPU when viewing certain directories) I've tried turning off all viewer plugins to no affect.
I think my question is a little misleading in so far as it really applies to the caching of the thumbnails. I should make it clear that if the thumbnails are cached the images do load quicker but slower than it used to be. It's during the caching process that the CPU becomes overloaded my PC slows to a crawl

If you disable thumbnail caching is it fast again?

Also, try temporarily turning off Preferences - Listers - Thumbnails: Use shell image extraction... near the bottom in case it's being caused by that.

Does it happen with all filetypes?

hi,

i had a similar problem and I also use NOD32... 2 things you can do....

  • Disable NOD32 from scanning the cache folder (what u did already)
  • Disable NOD32 from scanning the folder with the photos. No matter whether the thumbs are already cached or not, NOD32 still scans the folder photo by photo.
  • Tell NOD32 to not scan all files. Under threat protection module / AMON / SETUP / remove the check mark next to scan all files.

I found using either one of those methods to work best for me. All my photos are all together and not mixed in with other types of stuff, like movies and the like, so I set NOD32 not to scan my photo directory and all the subfolders.

Thanks fathertime for the suggestions but it doesn't make any difference if NOD32 is running or not. I tried all the different settings like excluding all image files from being scanned. I don't think it can be antivirus related.
If I turn thumbnail caching off it still is exactly the same.
In reply to Nudel it does make a difference regarding files types. My camera is set up to take 2 files of each picture, 1 jpg and 1 RAW (NEF) so most folders are 1/2 and 1/2. If the folder just contains jpegs then it is very slow; raw files it seems to just take forever and my computer is pretty much inoperable while it does it. I shoot with 4 gig cards so these folders contain many images.
Never used to be like this.
Many thanks for your time and suggestions so far guys.

Ahhh :slight_smile:

I suspect the RAW NEF files are being fully decoded to generate the thumbnails, which will indeed take a very, very long time. :slight_smile:

The NEF files probably have embedded thumbnails which Opus (via my jp2raw plugin that handles RAW files) can access instantly, but maybe you've configured the plugin to do a full image decode instead of using the embedded preview images?

Check the plugin's settings by going to Preferences - Plugins and configuring the TGA, JPEG 2000, PNM, Rasterfile and Raw Digital Camera plugin. (I really have to give it a better name one of these days. :slight_smile:)

There are separate tabs for Raw Thumbnails and Raw Viewers. Make sure the Raw Thumbnails tab is set to display Preview Image (fast) if available. Any other option (except Disabled) risks doing a full image decode for thumbnails which is very slow for most camera formats.

If you find this fixes the speed problem but also means you don't see any thumbnails for your NEF files, or you see thumbnails but they're all black, then it could be that your NEF files are in a format my plugin doesn't support yet, or that they don't actually contain any embedded thumbnails to display. If it's the former then feel free to upload an example file somewhere and I'll try to add support for the camera when I next do some work on the plugin. (I'm very much reliant on what the underlying code by Dave Coffin supports, but it's been a while since I updated it. I have some plans to combat that whole problem.)