User Manual

Table Of Contents
Rev 4.60
Mellanox Technologies
45
6 Performance Tuning
This section describes how to modify Windows registry parameters in order to improve performance.
6.1 General Performance Optimization and Tuning
To achieve the best performance for Windows, you may need to modify some of the Windows
registries.
6.1.1 Registry Tuning
The registry entries that may be added/changed by this “General Tuning” procedure are:
Under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters:
Disable TCP selective acks option for better cpu utilization:
Under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AFD\Parameters:
Enable fast datagram sending for UDP traffic:
Under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Ndis\Parameters:
Set RSS parameters:
6.1.2 Enable RSS
Enabling Receive Side Scaling (RSS) is performed by means of the following command:
6.1.3 Tuning the IPoIB Network Adapter
The IPoIB Network Adapter tuning can be performed either during installation by modifying
some of Windows registries as explained in Section 6.1.1, “Registry Tuning”, on page 45. or can
be set post-installation manually.
To improve the network adapter performance, activate the performance tuning tool as fol-
lows:
Step 1. Start the "Device Manager" (open a command line window and enter: devmgmt.msc).
Step 2. Open "Network Adapters".
Step 3. Select Mellanox IPoIB adapter, right click and select Properties.
Step 4. Select the “Performance tab”.
Step 5. Choose one of the tuning scenarios:
Please note that modifying the registry incorrectly might lead to serious problems,
including the loss of data, system hang, and you may need to reinstall Windows. As
such it is recommended to back up the registry on your system before implementing
recommendations included in this section. If the modifications you apply lead to serious
problems, you will be able to restore the original registry state. For more details about
backing up and restoring the registry, please visit www.microsoft.com.
SackOpts, type REG_DWORD, value set to 0.
FastSendDatagramThreshold, type REG_DWORD, value set to 64K.
RssBaseCpu, type REG_DWORD, value set to 1.
“netsh int tcp set global rss = enabled”