CPU and memory for winndows 11

It’s my impression that RT doesn’t really benefit from a powerful GPU. Is there much to gain beyond a Skylake Intel I7-8700 and 16GB of memory?

RT doesn’t use the GPU at all.

If you’re processing really large images or have lots of modules enabled, maybe more ram would help. Watch a system monitor while you process to see if your system is starting to swap.

Newer CPUs are generally faster, so better. But is it worth the money? That is a call only you can make.


No swapping at all and I have several modules open while pushing RT’s Local Adjustments.

I believe, this is a Windows-thing. Windows is running a lot of services you dont need most of the time.

For example:
I am working on a I7-7700 with 40 GB memory. The bigger memory ( from 16 GB before) didnt really speed up with RT. After stopping unnecessary services the speed of RT already increased fine. Then by activating the ultimate mode (https://allthings.how/how-to-enable-ultimate-performance-plan-in-windows-11/) the usability of RT became very good.
Since then, activating the ultimate mode before starting RT and come back to standard energy-saving-mode after using RT, works fine for me.

The size of your images has a big impact on the memory usage. I’m pretty sure that there is some benefit to having 32GB of memory when editing very large images, I think I can recall occasionally using over 16GB when editing 50MP images

I have an older, but still quite powerful Threadripper 1920x. Lots of cores, but the individual cores are each quite slow.

Using a lot of tools, especially lots of local adjustments seems to push it up noticeably.

Some tools really feel like they are pushing the CPU quite hard, for me, using dynamic range compression makes my computer grind to a halt.

I’m really curious as to how well RT takes advantage of higher amounts of CPU cores, its benefits from hyperthreading, and if fewer, faster cores like your i7-8700 will be more effective than a large amount of slower cores like my threadripper, or if it even matters at all.

My I would strongly guess, although I would need to test this, that having faster memory would bring a noticeable benefit, so you might want to try overclocking your memory if you haven’t already (Most memory advertised for something like “3600 MHz” dosen’t actually run that fast out of the box, usually it will be around 2133 MHz, and you need to manually load the memory’s XMP profile in your system BIOS).

I’m also very interested to find out how much memory latency impacts performance if it does, tightening timings could help too, but from my understanding most “Workstation” workloads aren’t very sensitive to memory latency.

There also is probably some benefit to having more memory channels, but possibly a penalty if CPUs using multiple dies like my threadripper due to memory latency. Specifically if there is a benefit to using NUMA vs SMP memory access. My prediction is that SMP could be slightly faster.

I might run some benchmarks while tweaking things and then report back later. Also it would be great to have a developer’s input on some of the memory usage stuff

I’m using XMP which gives me 2666MHz. I can see where going to the Ultimate or Performance plan could be a benefit, but I wouldn’t want to run it all the time. So, the idea of switching plans really doesn’t appeal to me.

It would be interesting to know how to get the most out of RT with cost considerations taken into into account.

Also, it’s good to know that the GPU is not the main consideration. Especially with the outrages pricing today.

I understand your point, but by combining these steps (activate - run RT - deactivate) in one batch-file, there would not be more effort than before.

Do you have the syntax for the batch file?

yes, no problem:

after once installing the ultimate mode by typing

powercfg -duplicatescheme e9a42b02-d5df-448d-aa00-03f14749eb61

in console with admin rights, you can check the ID of this scheme by typing: powercfg /L

On my machine i get this:
GUID des Energieschemas: 381b4222-f694-41f0-9685-ff5bb260df2e (HP Empfehlung)
GUID des Energieschemas: 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c (Höchstleistung)
GUID des Energieschemas: a1841308-3541-4fab-bc81-f71556f20b4a (Energiesparmodus) *
GUID des Energieschemas: ff81f4e0-a6f5-43e5-adcb-c969aa94f8b0 (Ultimative Leistung)

the last one is the ID you need for the batch file as follows, (pls adapt path and ID to your machine):

REM Ultimativer Modus (schaltet nur Bildschirm nach 15 min ab)
powercfg -s ff81f4e0-a6f5-43e5-adcb-c969aa94f8b0

call “c:\Program Files\RawTherapee\RawTherapee_dev_5.8-3160-g4059ae5bc_win64_release\rawtherapee.exe”

REM zurück in den Energiesparmodus
powercfg -s a1841308-3541-4fab-bc81-f71556f20b4a


I keep all unnecessary background services disabled other than Microsoft services.

I’m on a win 10-21H2 desktop. Components are an I7-8700 3.2GHz (4.6 turbo boost) with 2666 memory-16GB ram and a Nvidia GTX 1050 GPU. I’m using a balanced power scheme.

RT 5.9-7 loads in 6 seconds from and extracted zip file from @gaaned92

Now I know that the Linux users can do better, but no complaints here, at all.

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