With iGPU disabled in BIOS and a dedicated GPU in the one and only PCI slot:
>lsiommu 0|16:55:43
IOMMU Group 0:
00:00.0 Host bridge [0600]: Intel Corporation Device [8086:4650] (rev 02)
IOMMU Group 1:
00:01.0 PCI bridge [0604]: Intel Corporation 12th Gen Core Processor PCI Express x16 Controller #1 [8086:460d] (rev 02)
IOMMU Group 2:
00:06.0 PCI bridge [0604]: Intel Corporation 12th Gen Core Processor PCI Express x4 Controller #0 [8086:464d] (rev 02)