Product guide

Configuring on-demand scan file scan threads for
best performance
If you are running on-demand scans on a system with dual core processors, or very fast hard
drives, you can change some registry setting to improve on-demand scan performance.
CAUTION: This best practice contains information about opening or modifying the registry.
• The following information is intended for System Administrators. Registry modifications are
difficult to restore and could cause system failure if done incorrectly.
• Before proceeding, McAfee strongly recommends backing up your registry and understanding
the restore process. For more information, see: http://support.microsoft.com/kb/256986
• Do not run a .REG file that is not confirmed to be a genuine registry import file.
CAUTION: Where a specific set of files is identified by name for exclusion, exclude only those
files instead of the whole folder to minimize vulnerability. In some cases entire folders must be
excluded. Do not exclude any of these files based on the filename extension. For example, do
not exclude all files with the .dit extension.
Table 2: Scan thread setting
System user activitySystem utilizationScan thread
Above average — For example, workstations used for CPU intensive
activities such as computer aided design (CAD).
Low (single
threaded)
1
Typical — For example, individual workstations.Below normal1 per system core
Little — For example, servers.Normal3* per system core
* For example, dual core processors have 6 file scan threads configured by default.
See Configuring system utilization to match system use for additional information.
These default settings might not provide the best on-demand scan performance for system
with multi-core processors or very fast hard drives. McAfee encourages you to override the
default file scan thread configuration if your system:
• Is unresponsive during an on-demand scan or if the disk I/O is saturated. McAfee recommends
you lower the absolute number of file scan threads if your System utilization is set to Normal
and Below Normal.
• Has dual core processors, very fast hard drives (for example solid state drives [SSD]), or
your processors are underutilized. McAfee recommends you increase the absolute number
of file scan threads for all system utilization settings.
If your system displays any of these symptoms you should override the default file scan thread
configuration. Use the Registry Editor to modify the default file scan thread configuration using
the following:
1 From the VirusScan Console, right-click the Access Protection task and click Disable,
to temporarily disable Access Protection.
Configuring Performance Improvements
Configuring on-demand scan file scan threads for best performance
McAfee VirusScan Enterprise 8.830