I’m currently working on a project which leverages many PerformancePoint reports. The dashboards I’ve built use a fair number of analytic chart report objects on a single dashboard page  (at least 4, sometimes more).  When I ran many of these pages, Internet Explorer 7 generally pegged my CPU at 97%, and it was taking at least a minute for the page to render. Often, more than half of the report objects failed to render at all (“an unexpected error occured”).

I’m working in a single integrated environment (IE/SQL/SSRS/SSAS/PPS/MOSS all on one box), and I could tell that IE hogging up CPU wasn’t even allowing SSAS, SSRS, PPS and MOSS to do their work. While IE was sitting @ 97%, msmdsrv.exe or reportingservicesservice.exe might hit 2% CPU for a moment then drop back down to %0 when they usually used more CPU cycles.

Clueless and confused, I appealed to those smarter than I for help. Josh Unger, a PPS SDET at Microsoft suggested I try IE 8 on the image. I dutifully installed it, and whammo, problem solved.  My slowly running dashboards now rendered in no more than 15 seconds (and these were pages which included PAS and SSRS reports – the analytic charts returned within moments when they had been the problem children earlier).

I circled back and asked Josh exactly why life was so good in IE8, and he explained that IE 7 ( adhering to standards) only allows two concurrent connections, and therefore 2 AJAX requests made to the server at the same time. Perhaps that didn’t do a lot of good when I had 4, 6, 8, or more  AJAX controls on a page all wanting to do stuff? In IE 8, we can have up to 6 connections. 

I guess in my case getting more reports “working” on the server at the same time allowed them to begin returning more quickly. And once a report had returned, I suspect that the particular AJAX-based control that hosted it didn’t need any/as much CPU vs. having it sit there waiting for a connection to become available.

Thanks to Josh and thanks to IE8!