Good evening,
Could somebody please elaborate for me…
Are there any other benefits for going to 64bit apart from support for more memory?
Does the software have more functionality with 64bit?
If the raw files being processed are not filling memory on a 32bit system, is there any point for 64bit?
Thank you, kind regards
Mike
In a few words: definitively go for 64bit!
The long story: although theoretically Rawtherapee should be able to work on a single image with only 2-3GiB of RAM (the maximum amount addressable on Linux with 32bit OS), in practice (at least on Linux) it seems it can’t, thus making Rawtherapee extremely unstable.
I’m not a developer of Rawtherapee, and I didn’t look at this issue too much, but based on my own experience I can only say that since I migrated to 64bit Linux, Rawtherapee has crashed only a few times, compared to at least a couple of times per photo. (And in both cases I tried both builds by external parties, and custom compiled builds.)
Hope it helps,
Ciprian.
Additionally to the memory Issues, 64bit x86 uses 16 SSE registers, whereas 32bit X86 uses only 8. 64bit x86 generic builds support SSE2 by default, whereas 32bit x86 generic builds don’t support SSE without adding compiler switches (meaning the generic 32bit x86 builds provided by linux package maintainers won’t use SSE at all).
Ingo
Thanks for all the advise but this has led to more questions:
What Os is best for running rawtherapee? Windows/linux/osx?
If linux which distro?
opensuse of course. but I might be biased. 
Linux is built from better stuff than Windows in many ways. Doesn’t matter which distro as long as the software versions it provides aren’t outdated. RT gets developed on both platforms so it doesn’t really matter. You could argue that the best OS is the one the developers are using ;]
Good point morgan!
So can you clarify what operating system the developers of rawtherapee are using?
I’m using Win7/64 and Sabayon
+1 to “same OS as developers”.
What I’m realizing as I maintain a few computers for family members (Surface for wife, repurposed business desktops w/Mint for grandkids, and mine w/Ubuntu) is that, if you’re not into compiling source code a clean and simple update channel is imperative. That’s why I’m keeping my choice of OS to Debian derivatives, where I can either just install from the OS repository or add the PPA for others, and count on the package manager to keep things up to date. That lets me concentrate on my wife’s Surface; Windows has no such equivalent for apps.
Given that, Mint is my current choice; Debian derivative, simple desktop, well-maintained.
Oh, I do run RT on an Ubuntu desktop and a Windows tablet; for me, the critical difference is the 23" screen on the desktop, which has nothing to do with the OS…
I recently discovered Manjaro Linux XFCE edition 64 bits, an ArchLinux-based distro, and I like it a lot. But time will tell. On a regular basis though, I use Windows 7 64 bits, but if I can make RT packages for Windows from Virtualbox (Linux host, Windows guest), then I may switch to Linux.
So as you see, almost everyone has its own favorite.