X3 Migration Quickstart

Alveo X3522 User Guide (UG1523)

Document ID
UG1523
Release Date
2023-08-25
Revision
1.4 English

Read this Quickstart if you are migrating to the X3522 adapter from its predecessors that were designed by Solarflare, such as the 7000-series, 8000-series and XtremeScale X2-series. It outlines the major differences between the X3522 and its predecessors, and where to find out more:

Reduced Latency

  • ½ RTT latency for an X3522 is about 230 ns lower than for an X2522, measured using eflatency with a 200 byte packet over PCIe® Gen4 and 10 GbE.
  • The X3522 has been optimized for PCIe Gen4. Using PCIe Gen3 instead of Gen4 incurs a ½ RTT penalty of >80 ns.

See the Onload User Guide (UG1586) for full details of test setup, and for comprehensive latency values and graphs.

New RX and TX Data Path Designs

  • RX queues are managed by the driver and are shared between applications. Applications that share a queue should run on cores that share their L3 cache. Explicit huge pages are required.
  • TX always uses CTPIO, with 16 apertures per port instead of the single aperture used by the X2-series, allowing senders to have a dedicated aperture. This and other design improvements have made CTPIO more robust.

See Queue Handling, Receive and Transmit.

New Drivers and Software Packages

  • The X3522 uses a new Linux net driver named xilinx_efct, supplied separately from Onload.
  • The X3522 also uses the auxiliary bus driver. This is provided by some recent Linux distributions, or can be downloaded from AMD.
  • If you are using Onload you must build these new drivers first, before you build Onload. Likewise, you must load these drivers before you load Onload.
  • TCPDirect is now supplied in its own package, separately from Onload.

See the Alveo X3522 Installation Guide (UG1522), the Onload User Guide (UG1586) and the TCPDirect User Guide (SF-116303-CD).

Low Background Traffic Recommended

  • The kernel stack is not performant, and is only intended for light background traffic.
  • If any applications generate high traffic, consider accelerating them with Onload.
  • IGMP snooping is strongly recommended.

See the Onload User Guide (UG1586) to accelerate applications.

Focused Feature Set

  • Some features not normally used in low latency deployments because of their adverse impact have been removed.
  • The maximum MTU is 1500 bytes.

See Features.

Standardized Tools for Firmware Management

  • The sfupdate and sfboot utilities are no longer used.
  • The devlink or ethtool Linux utilities are instead used for update, configuration and information.

See Programming the X3522.

Higher Power Requirement

  • Power draw varies more with traffic load.
  • The X3522 uses more power than the X2-series.
  • Its airflow requirements are consequently higher.

See the Alveo X3522 Data Sheet (DS1002).

DSFP28 Cages

  • The X3522 has two DSFP28 cages, each of which supports two ports.
  • If you connect a DSFP28 cable, or a DSFP28 to SFP splitter, both ports for the cage are exposed.
  • If you connect an SFP cable, only the first port for the cage is exposed.
  • Ports are currently 10 GbE only.

See Ports and the Alveo X3522 Installation Guide (UG1522).