X3 Migration Quickstart

Alveo X3522 User Guide (UG1523)

Document ID
Release Date
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).