Maybee its nothing special to ryzen or threadripper. I'm suffering from this at least two years. Migrated from esxi to xcpng. On VMWare i had 93+ % with iperf to the hypervisor an into an vm.
With xcp-ng i get strange results on a 10 GB Network
VM > PC - 2.86 Gbits/sec
PC > VM - 1.98 Gbits/se
DOM > VM - 2.00 Gbits/sec
DOM > PC - 9.32 Gbits/sec
After reboot
PC > VM - 6.39 Gbits/sec
Maybee its a OS powermanagement issue?
The higher results after restart are suspicious. I already checked my bios to be sure dell power management is deactivated. Installed sysbench and tortured all cores for 90 seconds while watching the CPU P-States and they do not make sense. HTOP shows 100% load on all cores while xenpm get-cpufreq-states shows some core are far below their possible max. Base Clock is 2.5 GHz. The CPU can power up to 2.8 GHz at all cores and up to 3.4 GHz at 8 Cores. But half of the cores idle at 1.4 GHz in the test.
sysbench cpu --cpu-max-prime=2000000 --threads=32 --time=130 run
[20:36 localhost ~]# xenpm get-cpufreq-states
cpu id : 0
total P-states : 5
usable P-states : 5
current frequency : 1400 MHz
P0 [2500 MHz]: transition [ 1634]
residency [ 219694 ms]
P1 [2300 MHz]: transition [ 101]
residency [ 1623 ms]
P2 [2000 MHz]: transition [ 132]
residency [ 3774 ms]
P3 [1700 MHz]: transition [ 130]
residency [ 1433 ms]
*P4 [1400 MHz]: transition [ 1587]
residency [ 224679 ms]
cpu id : 1
total P-states : 5
usable P-states : 5
current frequency : 2500 MHz
*P0 [2500 MHz]: transition [ 2614]
residency [ 200126 ms]
P1 [2300 MHz]: transition [ 115]
residency [ 1469 ms]
P2 [2000 MHz]: transition [ 138]
residency [ 2631 ms]
P3 [1700 MHz]: transition [ 145]
residency [ 1288 ms]
P4 [1400 MHz]: transition [ 2556]
residency [ 227882 ms]
dmidecode CPU Info
Processor Information
Socket Designation: CPU1
Type: Central Processor
Family: Opteron 6300
Manufacturer: AMD
ID: 20 0F 60 00 FF FB 8B 17
Signature: Family 21, Model 2, Stepping 0
Flags:
FPU (Floating-point unit on-chip)
VME (Virtual mode extension)
DE (Debugging extension)
..............
Version: AMD Opteron(tm) Processor 6380
Voltage: 1.1 V
External Clock: 3200 MHz
Max Speed: 3600 MHz
Current Speed: 2500 MHz
Status: Populated, Enabled
Upgrade: Socket AM3
L1 Cache Handle: 0x0700
L2 Cache Handle: 0x0701
L3 Cache Handle: 0x0702
Serial Number: Not Specified
Asset Tag: Not Specified
Part Number: Not Specified
Core Count: 16
Core Enabled: 16
Thread Count: 16
Characteristics:
XCPNG:
XEN v8.2.1
Dell R714 AMD
Opteron(tm) Processor 6380 - 32 Core 2 Sockets
VM:
Debian 12 (4Cores)