Since you say it freezes when you play the sequence, I assume you have a 3rd party video card / device.
Can you tell us which version of CS you're using and the model of the video device.
Generally, you should be able to play the sequence in "near" real time.
http://tv.adobe.com/watch/cs6-creative-cloud-feature-tour-for-video/ge t-bet...
Even this Adobe video shows a slight delay between desktop and video monitor.