RT 5.4 Performance optimizations?

(Marcos) #1

Hello everyone!

First off, congrats to the devs as this piece of software has been saving my behind lately. Since I moved back to Paraguay from Canada it’s been difficult to continue spending as much as I was on software, and I don’t want to pirate it, either.

Out of all the free and affordable RAW editors out there, RawTherapee has THE best converters for my particular camera (GX85). The only thing that comes close is Capture One 11, which costs $200.

Sadly, I do miss the performance I used to get with paid software. Obviously not all of it ran great, but most was quite speedy and snappy, specially during the interface and previewing changes.

I’m installing 5.4 now after using 5.3 for a couple of months, and I’d like to know if there are settings I can apply in order to optimize the feeling around the UI and when previewing changes. I think my hardware is a good platform and should perhaps be performing better than it is.

Here’s my specs:

Win 10 x64
Intel i7 2670QM (4-core, 8-thread)
128GB SSD for OS and main apps (inc. RT) (though my pictures are located on a USB drive, nothing I can do about that as my collection won’t fit on my SSD)
Radeon HD 7770 1GHz, 1GB of VRAM dedicated GPU.

What can I do, my friends, to optimize RT so that it runs faster? Obviously I don’t want to lose too much quality at render (if at all), but I need to seed up my experience around the UI during editing.

Thank you guys! <3


It has been noted by several users that the gtk3 versions have some GUI slow downs on Windows but it hasn’t been reported consistently, and there has been some improvement since. E.g., on my system, making the RT window active from inactive had a long delay, and similarly within the app.

(Ingo Weyrich) #3

I worked really hard during the last years to speed up the image processing algorithms in RT and I think they are quite fast now on decent hardware when processing raw files in queue and even when changing settings in editor. Though I a gree with @afre about the gtk3 related issues, which slow down (as he mentioned) for example switching between RT and other apps.

(Marcos) #4

Thank you for the quick reply!

Is there a way to use previous versions of GTK? As long as the RAW conversion is equally as good, there are some features that I may not need from more recent releases?

(Marcos) #5

Yeah, the processing is fantastic! I’m mostly experiencing slow downs during UI navigation.

Is there a way to use previous versions of GTK? or which version of RT uses a previous version of GTK, so that it doesn’t slow my UI down?

I’m also experiencing slowdowns switching from one picture to another.

(Alberto) #6

if you are not doing that already, compiling from source to target your specific CPU is likely to give you some more performance. how much that is noticeable depends on the specific system I guess, but it’s worth trying.

(Marcos) #7

Sadly, I am not knowledgeable enough to do that without some help, though I’m more than willing to give it a shot if anyone can give me a hand!

Specially a 5.4-ish version with GTK2 underpinnings? Is that even possible or am I talking nonsense?

(downloading 5.0 R1 based on GTK2, but as it’s 32-bit I’m afraid a lot of my horsepower will go to waste, will report).

(Ingo Weyrich) #8

At least one gtk related slowdown is related to lensfun gui (the massive amount of lenses and cameras slows down the gui). You can try to work around that by deleting the lensfun stuff you don’t need.


I am not a programmer or hardware expert. I am using RT on Windows 10 and I can confirm that it is slower than e.g. Lightroom. However, the more I use RT and compare it to LR the more I realize that RT is slower, but it delivers better image quality than LR. I guess quality needs time. RT can be comparatively quick if you do not do much editing, e.g. only adjust white balance and maybe apply a tone curve or so. From my experience, especially sharpening and/or noise reduction is time consuming in RT. From my point of view it makes sense. In LR noise reduction / sharpening are not far as advanced or complex as in RT, you cannot adjust so many settings.
RT might not be the best program for you if speed is very important to you.
On the other hand, LR is also fairly complex, in the background it does work with multiple layers and masks. Though I must admit that I did not perform extremely complex editing with LR so far.
I do not think that RT is extremely slow.
I also have an older version of C1 but I do not use it any more. In terms of image quality it might indeed be better than LR. I used to like C1.

(Morgan Hardwood) #10

Delete your old options file to use the new defaults, to make sure we’re on the same page.


Not possible.

How bad are these Windows slow-downs you’re referring to?

You can always use or dual-boot Linux where GTK3 is snappy.

(Marcos) #11

I will try that as soon as I delete my options file for the 5.4 install.

(Ingo Weyrich) #12

I would try that a priori :wink:

(Marcos) #13

They are not critical but they are noticeable enough that they make the workflow less than ideal.

Dual boot is a no-go as I use this for work, which includes graphic design and other applications that I need Windows for.

(Morgan Hardwood) #14

That’s a non-argument. The whole point of dual-boot is to leave your Windows software intact.

Regardless, a video showing what it is you’re specifically referring to would help.


@Morgan_Hardwood At one point it took my system a minimum of 12s to make the gtk3 RT window active. I haven’t checked, or rather timed, the current release. That is a non-starter, but I do fire up RT when I need it.

(Marcos) #16

Not a non-argument as I need to use the files back and forth between applications. It would be simpler to use RT with slowdowns than use dual boot just to run RT under Linux, export the images and then boot Win to be able to use them.

I get the benefits of dual boot and once upon a time I was a huge fan. Right now I just need to do my work as quick as I can, sadly.

(Morgan Hardwood) #17

A non-argument of a non-argument surely flips over to become a valid argument? :wink:

(Alberto) #18

in my experience (Linux only) gtk3 is indeed slower than gtk2, but not dramatically so. I have no idea on windows though – as @morgan_hardwood wrote, a screencast showing the problem would be helpful

(Marcos) #19

I simply cannot refute an argument from a non-argument into a non-argument when it comes from a person whose profile image contains such a magestic cat.


@idillicah Or maybe use a virtual machine. It might be faster…