I process 50k aerial 20MP images regularly and have the following setup with two computers which I always use individually (when one is processing I am working on the other one for other projects)
RTX4090 or RTX3090 (two machines, works good on both)
i9-14900K or i9-13900K (two machines, works very good but they tend to overheat! So I am maxing the Watt usage to 215W to not get 100C or crashes or thermal throttling which is extreme!)
360 aio for the 14900k and 240 aio for 13900k cooler (please get the biggest cooler you can get and some good thermal paste)
192GB DDR5 RAM (Corsair Vengeance) or 128GB DDR5 RAM (Kingston Fury Beast) on the second machine (I have a lot of RAM because I generate 500 - 8K Textures for those types of projects)
Fractal North XL and Fractal North Case (Glass and mesh, don't see a difference, glass looks cooler)
ASUS ProArt Z790 Creator and gigabyte z790 aorus elite ax motherboard on second PC (Mainly use them for the plenty M2 SSD slots)
Lots of Samsung 990PRO M2 SSDs with 2TB or 4TB since a project can easily become up to 1000GB large in my case (without photos, just the metashape folder!)
You could also go with other similar SSDs but I usually only use the samsung ones.
Alignment on Highest takes max 2 days and Building 3d model on ultra takes around 4 days. For a 50k photo RTK-corrected drone set with 20MP each photo and complex geometry. Fair time for me.
By the way, the difference between computer 1 (with the better stuff) is substantial, but not worth the bigger price. I only use it for generation if I need something as quickly as possible. If there are 1-2 extra days I use the "worse" one for processing 24/7 and the better one for regular work.

Let me know if you have further questions. Please also let me know if you need help on processing such dataset because I do it all the time.