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BusyIndicator pegs CPU @ 100% on XP / IE 7 Platforms


We are seeing behavior where CPU utilization pegs near 100% on clients running Windows XP SP3 and IE 7. Same Silverlight 3 application running on a Win 7 / IE 8 environment doesn't have the issue. CPU utilization is not released after isBusy set to false either.
Using November 2009 SL Toolkit for SL 3. Apparently others have seen this as well.


mellorn wrote Oct 14, 2010 at 9:05 PM

I have case where SL 4 takes 100% of CPU of a core on several XP machines - IE 7 and IE 8. No problem with Win 7/IE9. April 2010 toolkit for SL 4. Response back to user window taking up to one minute.

pauljs wrote Oct 25, 2010 at 6:20 PM

I have exactly the same problem with the CPU utilization. It starts with busyInd.IsBusy = true, but it continues after busyInd.IsBusy = false (??????). I'm using Silverlight 3.0 and my clients are windows xp with ie 6.0, 7.0 and 8.0. Please, we need a fix on this soon as this tool is a basic-use tool! All the clients don't have PCs with intel i7 processors!

wrote Nov 9, 2010 at 8:11 PM

ikhwanhayat wrote Nov 10, 2010 at 11:43 AM

I got the same problem. I'm on a Windows 7, IE 8, Silverlight 4.

Does this have anything to do with themes? I'm using the JetPack theme.

Is there any known workaround?

wrote Nov 10, 2010 at 11:43 AM

flashfearless wrote Nov 10, 2010 at 3:07 PM

When I was at dev connections last week, someone suggested that the placement of the control within the xaml could cause this. Like if you move it to a different place in the content of the xaml, you might alleviate the problem. Don't know what guidance to give you on exactly where it makes a difference however. We wound up getting around it by skinning our own control.

pauljs wrote Nov 10, 2010 at 3:44 PM

In my case, I was using the control around a DataGrid, so when I placed it around a higher container (a Grid control) My problem gets solved. Another thing related on performance is that in the side server, you have to set busyInd.IsBusy=true just after YourCollection.Clear() method and before YourAsyncBusinessMethodCall, that way the DataGrid refresh time is faster.

wrote Nov 10, 2010 at 4:00 PM

wrote Dec 10, 2010 at 4:15 PM

RobARichardson wrote Dec 10, 2010 at 4:16 PM

Yup, I'm having this same problem as well. Removing the ProgressBar from the Template fixes the issue for me.

wrote Dec 15, 2010 at 9:21 PM

wrote Jan 11, 2011 at 8:06 PM

gius wrote Jan 11, 2011 at 10:15 PM

It seems that the excessive CPU consumption is caused by ProgressBar in BusyIndicator. See the last post here: . So if you remove any effects under the ProgressBar, you should be fine. Works for me!

gius wrote Jan 15, 2011 at 12:11 PM

Update: the excessive CPU consumption is caused by the ProgressBar in BusyIndicator interfering with DropShadow effect. See this: (the last demo).

wrote Apr 21, 2011 at 5:01 PM

wrote Aug 8, 2011 at 10:50 AM

wrote Apr 4, 2012 at 6:30 AM

wrote Feb 22, 2013 at 1:51 AM