Unresponsive drawing thumbnails in large photo directories

Long time Opus user here and someone that has real heartache working on any PC that doesn’t have it! I have an issue I hope someone can assist me with - forgive a bit of a ramble but I thought it best to put in as much information as I could, in case someone has a thought.

I have c.300k of photographs in 1,250+ directories (about 4TB) and have always found DO excellent as a thumbnail viewer to quickly navigate the directories and spot the photos I wish to view or edit. However, as my collection has grown and my cameras have advanced (current files are either 20MB JPGs or 50MB NEFS) I find myself really thinking twice before I click on the Thumbnail button as it can bring the PC to its knees. Not only does DO become pretty unresponsive until it finishes drawing the thumbnails in the directory I click on but it’s sometimes hard to get the PC itself to respond in terms of alt-tabbing to another program in the meantime. As soon as the thumbnails have been drawn, everything reverts to its normal snappy self.

It’s a reasonable spec machine (i7-6800K @3.6GHz, Rampage V Edition 10, 24GB DDR4 1066 RAM, GEForce GTX 1080, Win7 Pro 64). I also have a triple monitor setup (running through DisplayFusion) - Dell U3415W (3440x1440) Asus PB287Q (2160x3840) and BenQ PD3200U (2160x3840) – all at 60Hz. The DO thumbnail cache is on the C:\ drive (an 970EVO 1TB NVMe) and I’ve tried refreshing the thumbnails a couple of times as well. The photos themselves reside on a normal 7200 8TB HDD.

Q/. A while ago, I changed the Thumbnail threads in Preferences to 32. Would this have made any difference (i.e. in grabbing all the power in the system to do the thumbnails, making the PC unresponsive while it did the task)?

Any other suggestions as to how I might be able to make things quicker and/or stop the ‘unresponsiveness’?

Oddly enough, Windows Explorer is quite lot faster drawing the thumbnails, although it doesn’t do 1% of what DO does for me, so I’d really like to fix the problem if I can at all.

Many thanks for any suggestions! All the best!

The i7-6800K only has 6 cores (and so can run a maximum of 12 threads simultaneously), so telling Opus to use 32 threads for thumbnails will probably be counter-productive, as image decoding is mostly CPU-bound. I would try reducing the number to 10-12 and see if that improves things.

JPEGs should not take long to decode no matter how big they are (within reason), but I don't know about NEF files - possibly they are particularly CPU-intensive to decode.

Turning off Preferences / File Display Modes / Thumbnails / Load all thumbnails in a folder automatically can help reduce memory pressure in folders with huge numbers of images.

Many thanks Jon. I'll give both of those a whirl!

It's actually very interesting Jon as - to report back - I changed the threads to 10 and this definitely seems to have made a marked difference for the better.

Previously, once DO started to draw the thumbnails, just trying to click on the Details button to stop it was unresponsive and there was almost nothing you could do in the program until it had finished the task. With the reduced thread entry, not only does it seem to read the thumbnails more quickly but you can actually page down into the as-yet-undrawn thumbnails with the mouse (wheras before you couldn't even do this).

Quick additional question, if I may - can I assume that DO is a multi-threaded program that can utilise higher core number processors? Also, does changing the 'thumbnail threads' option in Preferences just relate to thumbnails (I assume so, thus the name!)? Is there anywhere else to direct the program as a whole to use more cores/threads or does it do this automatically?

Reason for asking is that I'm changing to a new PC soon based on a Ryzen 3960x processor (24 cores, 48 threads) - a move prompted mainly due to my issues with DO in this particular area.

Thanks again!

Opus is multithreaded but there aren't many places outside of thumbnail generation where it would typically use more than a few active threads. You'll also run into the SSD or HDD or network being the bottleneck at some point as the thumbnail threads increase.

Thanks Leo. Out of interest, can DOpus employ multiple cores?

Multiple threads will take advantage of multiple cores, yes.

Thanks!