Thanks for all input on this topic!

https://www.macworld.com/article/670873/which-mac-processor-apple-processor-comparison-m1-vs-intel.html

Mac processor comparison: M1 & M2 vs Intel

MAY 17, 2023 3:18 AM PDT

Not exactly the same hardware, but you might want to look at the  RTX 3070TI. About 10 days ago, I did this test:

Today before my new nVidia RTX 3079TI card arrived, I did a carefully timed test on a 10,000 ISO image with lots of noise. The rig is a I7-8700K, 64GB ram and Win 10 pro. I had the noise reduction setting at 59. The first test was with the GTX1660S in the computer, the second is with the new RTX 3070TI:

1660S - Expected time 1 min, Actual time 1:10

3070TI - Expected time 10 sec, Actual time 11sec.

The exact same image was used for the comparison.

The 3070TI times are very similar to what I'm getting on the same image on my MBP 16" 64GB M1 Max that I principally use for travel.

The files are 46MP Z9 images.

I have seen some numbers of RTX 3060 performance with Adobe Denoise on 50 megapixel photos (< 1 minute), but have not found so many M2 / M2 Pro numbers.

By @Stein99

Even my base M1 Pro, a decidedly midrange previous generation Apple Silicon processor, can do AI Denoise in 20–40 seconds (on a 24 megapixel Sony image). Those other reports with the M2 and higher end M1 (Max/Ultra) seem to get AI Denoise time down below 15 seconds, even with the Apple Neural Engine not being enabled because of that bug.

With AI Denoise under 15 seconds possible on both Mac and Windows, the decision should probably be made more on which OS you feel more comfortable with, and what other software you need to run. For example, if you also do a lot of graphics or video editing a Mac is fine, if you also do a lot of 3D and gaming then the Nvidia GPU becomes a real advantage.

My current system: MBP Pro 16" 2022 32-Core GPU | 16-Core Neural Engine/64GB

24.2MP Canon (R6 MII) takes 12 seconds from start to finish. Part of that is saving the new DNG, but the most processing is GPU related. 

My understanding is M2 isn't going to be much of a factor and that this will all get even faster (M1 or otherwise) when Apple/Adobe fixes a bug that D Fosse mentioned. 

From what I've seen, numbers for RTX 3060 and M2 are pretty much the same.

For Apple, their "neural engine" is currently bypassed by Adobe because of bugs. Once that is sorted out, it should pick up speed.

For Nvidia, timings improve dramatically as you move up to the higher and more expensive model numbers. I have an RTX 3060, and I get 33 seconds for 60 MP files from an a7r v. I sent a file to a friend with an RTX 3090, and he reported back with 13 seconds, or 2.5x as fast.