How does Reshade affect performance?

1. How much does Reshade affect FPS in general?
2. Are there any minimum recommended system requirements for AAA Open world games like The Witcher 3, Skyrim, etc...
3. In general, are there any particular types of pc components that will be more conducive to Reshade performance?
   • Like DDR4 4000mhz vs 3200mhz?
   • AMD vs Nvidia GPU?
   • Intel vs AMD CPU?
   • SATA vs PCI NVME SSD?

Some of the above questions may seem dumb, but I honestly have know idea what Reshade relies on the most for it's post processing. It may rely more heavily on the gpu, cpu, ram, or storage more than other comparable effects like Water, Shadows, Light Rays, etc.. . I just don't know.

1) Depends on the system. Can make no difference in best case and hurt a lot in worst case.
2) No. I don't have the resources to do the tests necessary to come up with such data.
3) ReShade is mostly GPU bound. The better the GPU, the faster ReShade will run. All other components don't make much of a difference at runtime. And especially in OpenGL ReShade runs better on NVIDIA GPUs.
The only exception is loading time. That part is CPU bound and not multi-threaded, so the better your CPU clock speed, the faster ReShade will load up (doesn't matter how many cores it have).

Really appreciate the reply man! Totally understand there's not clear answers to any of my questions except the last. I kind of knew it mostly comes down to the GPU. Best of luck on your current roadmap for Reshade!

Quick note that different effects also have a big performance variance if your gpu is older/weaker.
On my 560 ti, color effects like the SweetFX packages (LiftGammaGain, Vibrance, Levels, etc.) would have basically no performance drop, while Bloom would reduce fps by ~20% and MXAO would reduce it by over 50%.

In my experience, it dependent on what shaders you use. The cool thing is that often you got options as we have diffrent versions of shaders that does the similar things.

Colorfullness < Viberance
Adaptive sharpen < Lumasharp
SMAA < FXAA

Just example, it worth taking time and try them out. What performance is probably highly dependent on your GPU. Also some shaders will have very diffrent performance depending on settings.

Also Reshade has performance metering built in. There is performance tab, where you can see how much a individual shader uses. That should get indication how demand different shaders are.

As mentioned before, it really depends on shader type.
- Simple color/brightness/gamma/contrast correction shaders are usually quite cheap, costing maybe 1% or 2%.
- Post processing AA filters like SMAA, FXAA are also not too bad, maybe 2%-5%.
- Sharpening/softening is similar to the AA filters, 2%-5%
- More expensive filters are usually 'depth of field' or 'bloom', with up to 20% (depends also lot on GPU and scene)
- Most expensive, as mentioned before, are probably ambient occlusion shaders like MXAO with up to 30% performance hit (50% as mentioned before I haven't seen but that again depends on GPU model)

And lastly don't forget, some shaders operate based on the resolution of the game, meaning the higher the res you run the game the more processing time shaders require. Some shaders at 4K are substantially more demanding than at 1008p.

Some? ReShade applies pixel shaders, every single shader scales performance wise somewhat proportionally with pixel count. The only reason shaders seem to take less fps away on high resolutions comparably is because the base fps are lower. 1ms additional frame time on 100 fps base makes about 91 fps, 1ms on 10 fps base results in 9.9.

Worth noting, it can be big difference how much work different resolutions impact on performance. I can afford to use DSR in some games.

1080p= Baseline
1440p= 1.78x times the pixels
2160p(4k)= 4x times pixels

So roughly you can expect how much more work everything takes.

What about making certain individual shade effects rendered by either CPU or GPU on a case by case basis? Modern CPU's have a ton of excess cores available. It would be terrible for AA I imagine, but like a sharpen/blurr effect perhaps it would be fine to run on a otherwise idle CPU core.

That's not how computers works. CPU/GPU architecture is very different.

crosire wrote: That's not how computers works. CPU/GPU architecture is very different.

and Reshade can use iGPU of intel processors for shaders or impossible ?