Chapter 2: X3 Migration Quickstart - Xilinx Alveo X3522 User Manual

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Installation manual (38 pages)

Table Of Contents

Table of Contents

X3 Migration Quickstart

Read this Quickstart if you are migrating to the X3522 adapter from its predecessors that were

outlines the major differences between the X3522 and its predecessors, and where to find out

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

• 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,

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 Xilinx.

• 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).

UG1523 (v1.0) October 18, 2022

Alveo X3522 User Guide

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