I’m building up a new server on an ASRock X470 Taichi with a Ryzen 5 3600. When I check IOMMU it shows only 8 groups with both GPUs together in the same group. This doesn’t match several examples I’ve seen on this forum for the very same mobo (e.g. 20+ groups with GPUs in different ones).
I’ve read elsewhere that the BIOS and kernel can impact this, but after upgrading to the latest BIOS and moving to 5.3 I still see the same grouping.
Any ideas on why this may be? Is it the CPU limiting the groups?
For ref, below is what I see.
IOMMU Group 0 00:01.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
IOMMU Group 0 00:01.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge [1022:1483]
IOMMU Group 0 00:01.3 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge [1022:1483]
IOMMU Group 0 01:00.0 Non-Volatile memory controller [0108]: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983 [144d:a808]
IOMMU Group 0 02:00.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Device [1022:43d0] (rev 01)
IOMMU Group 0 02:00.1 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset SATA Controller [1022:43c8] (rev 01)
IOMMU Group 0 02:00.2 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Bridge [1022:43c6] (rev 01)
IOMMU Group 0 03:00.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port [1022:43c7] (rev 01)
IOMMU Group 0 03:02.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port [1022:43c7] (rev 01)
IOMMU Group 0 03:03.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port [1022:43c7] (rev 01)
IOMMU Group 0 03:04.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port [1022:43c7] (rev 01)
IOMMU Group 0 03:09.0 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] 400 Series Chipset PCIe Port [1022:43c7] (rev 01)
IOMMU Group 0 04:00.0 USB controller [0c03]: ASMedia Technology Inc. ASM2142 USB 3.1 Host Controller [1b21:2142]
IOMMU Group 0 05:00.0 SATA controller [0106]: ASMedia Technology Inc. ASM1062 Serial ATA Controller [1b21:0612] (rev 02)
IOMMU Group 0 06:00.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1184e PCIe Switch Port [1b21:1184]
IOMMU Group 0 07:01.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1184e PCIe Switch Port [1b21:1184]
IOMMU Group 0 07:03.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1184e PCIe Switch Port [1b21:1184]
IOMMU Group 0 07:05.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1184e PCIe Switch Port [1b21:1184]
IOMMU Group 0 07:07.0 PCI bridge [0604]: ASMedia Technology Inc. ASM1184e PCIe Switch Port [1b21:1184]
IOMMU Group 0 08:00.0 Network controller [0280]: Intel Corporation Dual Band Wireless-AC 3168NGW [Stone Peak] [8086:24fb] (rev 10)
IOMMU Group 0 0a:00.0 Ethernet controller [0200]: Intel Corporation I211 Gigabit Network Connection [8086:1539] (rev 03)
IOMMU Group 1 00:02.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
IOMMU Group 2 00:03.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
IOMMU Group 2 00:03.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge [1022:1483]
IOMMU Group 2 00:03.2 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge [1022:1483]
IOMMU Group 2 0e:00.0 VGA compatible controller [0300]: NVIDIA Corporation NV44 [GeForce 6200 LE] [10de:0163] (rev a1)
IOMMU Group 2 0f:00.0 VGA compatible controller [0300]: NVIDIA Corporation Device [10de:1e89] (rev a1)
IOMMU Group 2 0f:00.1 Audio device [0403]: NVIDIA Corporation Device [10de:10f8] (rev a1)
IOMMU Group 2 0f:00.2 USB controller [0c03]: NVIDIA Corporation Device [10de:1ad8] (rev a1)
IOMMU Group 2 0f:00.3 Serial bus controller [0c80]: NVIDIA Corporation Device [10de:1ad9] (rev a1)
IOMMU Group 3 00:04.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
IOMMU Group 4 00:05.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
IOMMU Group 5 00:07.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
IOMMU Group 5 00:07.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Internal PCIe GPP Bridge 0 to bus[E:B] [1022:1484]
IOMMU Group 5 10:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Function [1022:148a]
IOMMU Group 6 00:08.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
IOMMU Group 6 00:08.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Internal PCIe GPP Bridge 0 to bus[E:B] [1022:1484]
IOMMU Group 6 00:08.2 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Internal PCIe GPP Bridge 0 to bus[E:B] [1022:1484]
IOMMU Group 6 00:08.3 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Internal PCIe GPP Bridge 0 to bus[E:B] [1022:1484]
IOMMU Group 6 11:00.0 Non-Essential Instrumentation [1300]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Reserved SPP [1022:1485]
IOMMU Group 6 11:00.1 Encryption controller [1080]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse Cryptographic Coprocessor PSPCPP [1022:1486]
IOMMU Group 6 11:00.3 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] Matisse USB 3.0 Host Controller [1022:149c]
IOMMU Group 6 11:00.4 Audio device [0403]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse HD Audio Controller [1022:1487]
IOMMU Group 6 12:00.0 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] [1022:7901] (rev 51)
IOMMU Group 6 13:00.0 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] [1022:7901] (rev 51)
IOMMU Group 7 00:14.0 SMBus [0c05]: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller [1022:790b] (rev 61)
IOMMU Group 7 00:14.3 ISA bridge [0601]: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge [1022:790e] (rev 51)
IOMMU Group 8 00:18.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 0 [1022:1440]
IOMMU Group 8 00:18.1 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 1 [1022:1441]
IOMMU Group 8 00:18.2 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 2 [1022:1442]
IOMMU Group 8 00:18.3 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 3 [1022:1443]
IOMMU Group 8 00:18.4 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 4 [1022:1444]
IOMMU Group 8 00:18.5 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 5 [1022:1445]
IOMMU Group 8 00:18.6 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 6 [1022:1446]
IOMMU Group 8 00:18.7 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Matisse Device 24: Function 7 [1022:1447]