User Manual
Table Of Contents
- Mellanox WinOF VPI User Manual
- Table of Contents
- List of Tables
- Document Revision History
- About this Manual
- 1 Introduction
- 2 Driver Features
- 3 Deploying Windows Server 2012 with SMB Direct
- 4 Driver Configuration
- 5 Performance Tuning
- 6 OpenSM - Subnet Manager
- 7 InfiniBand Fabric
- 7.1 Network Direct Interface
- 7.2 part_man - Virtual IPoIB Port Creation Utility
- 7.3 InfiniBand Fabric Diagnostic Utilities
- 7.4 InfiniBand Fabric Performance Utilities
- 7.4.1 ib_read_bw
- 7.4.2 ib_read_lat
- 7.4.3 ib_send_bw
- 7.4.4 ib_send_lat
- 7.4.5 ib_write_bw
- 7.4.6 ib_write_lat
- 7.4.7 ibv_read_bw
- 7.4.8 ibv_read_lat
- 7.4.9 ibv_send_bw
- 7.4.10 ibv_send_lat
- 7.4.11 ibv_write_bw
- 7.4.12 ibv_write_lat
- 7.4.13 ibaddr
- 7.4.14 ibcacheedit
- 7.4.15 iblinkinfo
- 7.4.16 ibqueryerrors
- 7.4.17 ibsysstat
- 7.4.18 perfquery
- 7.4.19 saquery
- 7.4.20 smpdump
- 8 Software Development Kit
- 9 Troubleshooting
- 10 Documentation
Performance TuningRev 4.3
Mellanox Technologies
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The number of receive buffers (default 1024).
• Send Buffers
The number of sent buffers (default 2048).
• Performance Options
Configures parameters that can improve adapter performance.
• Interrupt Moderation
Moderates or delays the interrupts’ generation. Hence, optimizes network throughput and CPU uti-
lization (default Enabled).
• When the interrupt moderation is enabled, the system accumulates interrupts and sends a single interrupt
rather than a series of interrupts. An interrupt is generated after receiving 5 packets or after 10ms from
the first packet received. It improves performance and reduces CPU load however, it increases latency.
• When the interrupt moderation is disabled, the system generates an interrupt each time a packet is
received or sent. In this mode, the CPU utilization data rates increase, as the system handles a larger
number of interrupts. However, the latency decreases as the packet is handled faster.
• Receive Side Scaling (RSS Mode)
Improves incoming packet processing performance. RSS enables the adapter port to utilize the
multiple CPUs in a multi-core system for receiving incoming packets and steering them to the des-
ignated destination. RSS can significantly improve the number of transactions, the number of con-
nections per second, and the network throughput.
This parameter can be set to one of the following values:
• Enabled (default): Set RSS Mode
• Disabled: The hardware is configured once to use the Toeplitz hash function, and the indirection table is
never changed.
• Receive Completion Method
Sets the completion methods of the received packets, and can affect network throughput and CPU
utilization.
• Polling Method
Increases the CPU utilization as the system polls the received rings for the incoming packets. How-
ever, it may increase the network performance as the incoming packet is handled faster.
• Interrupt Method
Optimizes the CPU as it uses interrupts for handling incoming messages. However, in certain scenar-
ios it can decrease the network throughput.
• Adaptive (Default Settings)
A combination of the interrupt and polling methods dynamically, depending on traffic type and net-
work usage. Choosing a different setting may improve network and/or system performance in certain
configurations.
• Interrupt Moderation RX Packet Count
Number of packets that need to be received before an interrupt is generated on the receive side
(default 5).
IOAT is not used while in RSS mode.