You may prefer to search for Computers under Manage>Computers as they "type" or just after they hit "Enter".
ITMS 8.x
Prior to ITMS 8.5 RU3 release, you were able to modify this behavior on the SMP Console under Settings>Console>ITMS Management Views. You had the options for:
Post ITMS 8.5 RU3 Release, due to the changes done to move away from Silverlight dependencies and embrace HTML5 in our pages, a new CoreSetting called "ECV.SearchAsYouType" has been introduced. Previous limitations and slowness on this Search functionality were removed, so there was no need for customers to have these options available in a separate menu option as before.
You can access this new setting under Settings>Notification Server>Core Settings
Then search for "ECV.SearchAsYouType".
When this setting is set to "True", the Search behavior now allows you to search as you type but there is an automatic delay of few seconds before actually start searching.
When set to "False", it will search until to hit "Enter".