How does cpu usage effect antivirus scans?

[tpolcha]

I use Microsoft Security Essentials free.  The settings allow you to 'Limit CPU usage during the scan'. 

Please explain the hows and whys?  I googled it but.....

I guess scan times change and am not sure if a high or low setting alters the effectiveness of the scan.

Thanks,

[Allan]

Lower cpu usage results in more cycles available for other apps and slower scan speed.

[patio]

Personally i schedule my scans to run at 4 AM when i'm asleep...

[tpolcha]

So the only variable that changes with different settings is how long the routine scan takes?

[patio]

Correct.