m2 slot

I have a MSI Z790 tomahawk DDR5 mobo. I installed 2 identical KC3000 NVME, one in M2 slot 1 and the other in M2 slot 4. I didn't pay attention when I installed OS and now I have no clue whether the boot drive is the one from M2_1 (from CPU) or the M2_4 (from chipset). I looked into disk...