Additional information about Symantec Endpoint Protection scan tuning options.
Tuning the performance of scheduled scans can be accomplished on the Symantec Endpoint Protection Manager (SEPM) within the Antivirus/Antispyware policy via Scheduled Scan > Advanced Scanning Options > Tuning. Tuning the performance of on-demand scans can be done in the Antivirus/Antispyware policy, under Administrator Defined Scans > Administrator On-Demand Scan Settings > Advanced Scanning Options > Tuning.
The Scan Tuning feature in Symantec Endpoint Protection works by monitoring file Input and Output (IO). If Symantec Endpoint Protection is doing most of the file IO, the scan will continue unthrottled. If another process is performing a large amount of IO then Symantec Endpoint Protection will throttle the scan until the IO caused by other processes is reduced. If a scan is throttled, Symantec Endpoint Protection will continue to scan but at a much slower speed.
On Windows, the tuning options behave as follows:
Symantec Endpoint Protection scan tuning does not change the scan process priority; instead, it uses the more efficient method of monitoring file IO as described above.
On macOS, the tuning options behave differently: