RT5 and speed query

(Ingo Weyrich) #21

@floessie we should review this. Seems it does not work…

(Alberto) #22

I’m aware of the dangers in general, but do you have any specific example for RawTherapee? I would especially be interested if the flag results in some sub-optimal output (e.g. causes some artifacts).

Also, I should clarify that I’m not recommending to build with -ffast-math by default, I’m only suggesting it as something worth trying to get some extra speed. Personally, I haven’t experienced any issues with RT since I moved to 64 bit, and I’m using -ffast-math on both my machines. But maybe I’m just lucky :slight_smile:

(Alberto) #23

I noticed that, and that’s why I set -ffast-math only in RTENGINE_CXX_FLAGS.
I did it out of curiosity at the beginning, but since I didn’t notice anything strange, I left it on…

(Ingo Weyrich) #24

@agriggio you should not use Colour toning then

(Alberto) #25

noted, thanks for the pointer!

(Flössie) #26

@agriggio If you want more speed for free, try building with LTO enabled. Last time I tried it (a year ago or so) it made a difference.

(Alberto) #27

Thanks for the tip. I just tried, but I get a bunch of undefined references when linking :frowning: (I simply set WITH_LTO=ON, is there anything else needed?)

(Flössie) #28

Yes: In addition to -DWITH_LTO=ON add -DCMAKE_AR=/usr/bin/gcc-ar and -DCMAKE_RANLIB=/usr/bin/gcc-ranlib to the cmake line.


(Alberto) #29

Thanks, works now!

(Stefan Chirila) #30

Don’t know about Ubuntu, but using Debian 8 or the Debian 9RC any version built on GTK3 is slow. The Gtk2 builds that allow using the system’s own theme in settings, work nice and snappy; no real speed difference between my 2GB RAM laptop and my 16GB RAM tower (obviously exports will be faster on the tower through).

I assume it must be because my debian hasn’t yet propperly adopted gtk3 yet?

(Andrew) #31

I’d be interested in what goes faster, and how much faster it goes please.

(Alberto) #32

goes about half a second faster (with your pp3). Nice considering that it is “for free”, but it won’t change your day…

(Andrew) #33

thanks, & agreed!

(Mica) #34

Debian stable has a pretty dated version of GTK3, like 3.14 or something. But a new release is just around the corner!

(Flössie) #35

That’s because Ingo has done such a tremendous job optimizing RT! There’s not much room left for LTO but to inline things a bit better. :smile:

(Flössie) #36

Sure (and Stefan already mentioned Debian 9RC), but the core processing doesn’t depend on the GUI toolkit, so that’s indeed interesting.

(Ingo Weyrich) #37

There’s some potential to optimize Only edges sharpening which currently is quite slow.
I already checked for the bottlenecks and found some.
@floessie Are you interested in another fun optimization session? I would open an Issue then and share my first results.


(Ingo Weyrich) #38

Can you post content of AboutThisBuild.txt please?

(Alberto) #39

well, let me take this opportunity to thank all the RT developers for their amazing work!

(Dariusz Duma) #40

I’ve removed 03 for the final release… I don’t know why - maybe because to keep recommendations from final readme file. My ‘unstable’ branch is compiled with 03. Well, I will add this again to stable branch - expect new compilation in few hours.