My groupings (with ACP overide) running a 1700 and GA-AX370 Gaming K5 motherboard:
IOMMU group 0
[1022:1452] 00:01.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1452
IOMMU group 1
[1022:1453] 00:01.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 1453
IOMMU group 2
[1022:1452] 00:02.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1452
IOMMU group 3
[1022:1452] 00:03.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1452
IOMMU group 4
[1022:1453] 00:03.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 1453
IOMMU group 5
[1022:1452] 00:04.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1452
IOMMU group 6
[1022:1452] 00:07.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1452
IOMMU group 7
[1022:1454] 00:07.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 1454
IOMMU group 8
[1022:1452] 00:08.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1452
IOMMU group 9
[1022:1454] 00:08.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 1454
IOMMU group 10
[1022:790b] 00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 59)
[1022:790e] 00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 51)
IOMMU group 11
[1022:1460] 00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1460
[1022:1461] 00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1461
[1022:1462] 00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1462
[1022:1463] 00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1463
[1022:1464] 00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1464
[1022:1465] 00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1465
[1022:1466] 00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1466
[1022:1467] 00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Device 1467
IOMMU group 12
[1022:43b9] 03:00.0 USB controller: Advanced Micro Devices, Inc. [AMD] Device 43b9 (rev 02)
[1022:43b5] 03:00.1 SATA controller: Advanced Micro Devices, Inc. [AMD] Device 43b5 (rev 02)
[1022:43b0] 03:00.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43b0 (rev 02)
[1022:43b4] 04:00.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43b4 (rev 02)
[1022:43b4] 04:02.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43b4 (rev 02)
[1022:43b4] 04:03.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43b4 (rev 02)
[1022:43b4] 04:04.0 PCI bridge: Advanced Micro Devices, Inc. [AMD] Device 43b4 (rev 02)
[1b21:1343] 05:00.0 USB controller: ASMedia Technology Inc. Device 1343
[8086:1539] 06:00.0 Ethernet controller: Intel Corporation I211 Gigabit Network Connection (rev 03)
IOMMU group 13
[10de:128b] 09:00.0 VGA compatible controller: NVIDIA Corporation GK208 [GeForce GT 710B] (rev a1)
[10de:0e0f] 09:00.1 Audio device: NVIDIA Corporation GK208 HDMI/DP Audio Controller (rev a1)
IOMMU group 14
[1022:145a] 11:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Device 145a
[1022:1456] 11:00.2 Encryption controller: Advanced Micro Devices, Inc. [AMD] Device 1456
[1022:145c] 11:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Device 145c
IOMMU group 15
[1022:1455] 12:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Device 1455
[1022:7901] 12:00.2 SATA controller: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] (rev 51)
[1022:1457] 12:00.3 Audio device: Advanced Micro Devices, Inc. [AMD] Device 1457