Hello, I am new here, sorry if this was discussed before but I didn’t find any relevant results using search.
RawTherapee is very sluggish for me - switching from one CR2 file to another in the library mode takes around 2-3 seconds, with all CPU cores running at 100% for that time (around 4,8 GHz). The folder has 10 files in it.
I am running an i9 9900K and 1080Ti in 4K display resolution.
Switching to HD makes no difference.
Running SSDs only, OS and files are on a WD Black SN750 1TB M.2 NVMe.
Is this normal or am I missing some setting?
I have been using Adobe LR in the past which was much quicker, but they just completely changed CC for much worse and I decided to try something else
Thanks!
Is this on Windows?
Yup Win10
The 1080ti is of no use at this time, as RawTherapee can not make use of the GPU.
Usually this problem is just that a 4k screen is a ton of pixels to render to the screen, but you say that 1080p isn’t any different…
Can you make sure your antivirus and/or windows defender isn’t interfering?
Yes resolution does not seem to make any difference.
I tried disabling Win defender, no change either. Don’t have any separate antivirus installed.
This is on a clean Win10 install after completing all updates, nothing should be interfering I would think.
Weird :/. I will keep using LR for now and try some open source later :).
You didn’t even tell us which version of RawTherapee you are using … weird.
The newest stable 5.5.
I will try some older build just in case.
That’s almost impossible. Decoding of high MP Canon CR2 files takes more than one second on my machine and uses only 2 cores. After decoding all cores should be used, that’s perfectly fine. But during the first second you should see only 2 cores being used.
Same with 5.4, probably no point in trying even older ones.
Yes very strange, this is what all 16 threads look like when I double-click between 10 files…
Everything is snippy in Adobe LR, so I assume my CPU itself is fine. Should I try submitting a bug report with some logs?
Not yet. Let’s first try to see what’s going on. What Canon are the CR2 files from?
Also, can you make sure you use the rawtherapee.exe file and not the rawtherapee-debug.exe file which is much, much slower.
Canon EOS 7D, a few files here:
https://drive.google.com/open?id=1ffAgGJHqhfrphaDzNLMV2VW1nRWhmT8e
I can confirm the rawtherapee.exe is being used ;).
@karolans Though the file extension of the files on the google drive are .CR2, the files are jpg files…
Ah ok Drive does compression on upload to save space.
Maybe Filebin works better?
https://filebin.net/5o8369f1fqu5knu0
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Filebin worked fine 
So we come closer to what happens:
When opening one of this CR2 files the first time in RawTherapee, RT decodes the file 3 times, one time to generate the thumbnail, one time for the preview in editor and another time for the auto-matched tone curve.
That’s something I should definitely improve. Thanks for bringing that to attention 
That’s not an issue special to CR2 files, but these files are among the slowest to decode (for example your files need about 0.5 seconds to decode on my quite fast machine while Sony ARW files of same size only need about 0.1 second). 3 times 0.5 seconds meens 1.5 seconds for opening the files the first time.
Switching between the files again should be much faster as the thumb is already built and the result of the tonecurve match is cached, so the cr2 just has to be decoded only once for the editor.
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Another thing which has some impact on processing time in preview mode is, that the default profile includes lens correction, whichs processing time is proportional to preview area (more pixels in preview => slower) and you’re using a 4K display.
On HD displays that’s not a real issue, but I will try to make a speedup nevertheless, as 4K displays will be more common…
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Ok awesome, good to hear you are working on it. Thanks and good luck!
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