Does each update consumed by lightstreamer run in a seperate JS-worker?
no it doesn't.

I haven't heard of anything similar to your issue before so that I haven't specific suggestions for you. Usually the heavy part is the DOM manipulation; try to remove any update on the screen to see if the browser still have the issue.

If the issue is still there you may use IE8's developer tools profiler and try to understand where time is spent.

Also note that the client will switch to a polling session if the slowing-algorithm is enabled and the client is slow handling the updates; see http://www.lightstreamer.com/docs/cl...SlowingEnabled. Is the algorithm enabled on your application? Do you notice the client switching to polling in your onStatusChange callback?

HTH.