500 GB for Windows gaming - will fit 8-10 decent games and I personally feel my SATA loads Fallout4 levels way too slow, I can't really imagine any gaming performance on USB3 platter drive.
Storing music on an external (even USB3 platter) disk is however absolutely OK. Small files, accessed every 4-6 minutes, that's not a problem. I have a backup of my library on an external disk I take with me traveling and the speed is not an issue.
It's splitting two disks exactly what I call "creating weak links". One wrong move on a partition table and your both partitions are gone.
Also, to run Monterey on this computer you will need to resort to OpenCore (unless you want to stick with Big Sur), so it makes the UEFI approach to Windows (even Windows 11) even more obvious.
My gaming uses will not be for massive games. I do play Brawlhalla, Minecraft , Team Fortress 2 , Sea of Thieves and league of legends and that’s it lol . My previous 27" 2011 iMac died from GPU heating issue so i am scare of doing triple A gaming no matter what , even if I have a 4gb r9 m295x.
About splitting drives… Since I’ve already bought my external HDD, I think you just have to say good luck to me haha
Also my 2014 iMac don’t have Monterey , the last available is big sur. But talking about UEFI , I have no idea of what it is , and what makes it different from Legacy.
Also thank you very much for all the previous explaining sir , you help me so much . I am no pro information or anything, but I’ve managed to gain so much confident with such clear explanation on macrumors