12. How to get best performance on AMD platform

This document provides a detailed, step-by-step guide on configuring AMD EPYC System-on-Chip (SoC) for optimal performance in DPDK applications across different SoC families.

The overall performance is influenced by factors such as BIOS settings, NUMA per socket configuration, memory per NUMA allocation, and proximity to IO devices.

These are covered in various sections of tuning guides shared below.

12.1. Tuning Guides for AMD EPYC SoC

  1. MILAN

  2. GENOA

  3. BERGAMO|SIENNA

12.2. General Requirements

12.2.1. Memory

Refer to the Memory Configuration section for specific details related to the System-on-Chip (SoC).

Note

As a general guideline, it is recommended to populate at least one memory DIMM in each memory channel. The optimal memory size for each DIMM is at least 8, 16, or 32 GB, utilizing ECC modules.

12.3. BIOS

Refer to the BIOS Performance section in tuning guide for recommended settings.

12.4. Linux GRUB

Refer to the Linux OS & Kernel in tuning guide for recommended settings.

12.5. NIC and Accelerator

AMD EPYC supports PCIe Generation of 1|2|3|4|5 depending upon SoC families. For best performance ensure the right slots are used which provides adequate bandwidth.

Use lspci to check the speed of a PCI slot:

lspci -s 41:00.0 -vv | grep LnkSta

LnkSta: Speed 16GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- ...
LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete+ ...

12.6. Compiler

Refer to the Compiler Flags in tuning guide for recommended version and -march flags.

12.7. Max LCores

Refer to the Compilation in tuning guide for allowing more threads to run as DPDK lcores.

12.8. Power

12.8.1. Core

AMD EPYC SoC supports CPU power functions via rte_power API from 23.11 LTS onwards. These are tested and validated on MILAN, GENOA, BERGAMO and SIENA using Linux kernel 6.4 and above with amd_pstate power driver.

Note

  • Power libraries are supported on Linux only.

  • DPDK uncore support on Linux is work in progress.