Ajax update panel and performance

Dear all

I am using asp.net 2.0 and ajax. in my ui i have multiple controls. some i need to update some other dont want to update. but the controls that i need to update is not in serial order in ui. so i need to place them in multiple update panels. is that a performance issue if i use multiple update panels(may be 6 or 7 update panels in 1 UI) ?

Thanks

Update panels makes client [browser] little heavy. performance is same, since it postback's the whole view state. It is just for user experience. But putting more update panels and showing too much data in update panels makes browser too heavy it might crash the browser