I've noticed in a test site of DNN 5.1.0 on localhost that IE8 has serious performance lag issues with DNN 5.1 that are not present when in compatibility mode.  Basically, the more modules you add to a page, the slower the response time becomes for mouse hovers over links and menus.  I've been working on a skin and containers, and have a single test page for the containers.  Currently, there is about 40 containers on the page which is definitely not a normal circumstance, but it does clearly show that the more modules on a page the slower IE is to respond.  In menus, there is almost 1 to 2 seconds lag time before a mouse hover gets a response for hovering a link or a menu item.  You can actually quickly move the mouse to a menu item and then have to wait for the menu highlight to catch up.  Also, the min/max buttons will minimize and maximize a module in super-ultra slow motion.

I have the IE8 memory thing set to off in the Advanced IE Options (more to do with "online attacks" or something like that?).  In compatibility mode none of this is a problem, response time never slows or lags at all.  This occured with a custom skin as well as the default Minimal Extropy skin.  I'm not sure if module content adds to this or not, the modules I have are HTML modules only with only two or three sentences in them.  With and without javascripts that are not native to DNN.  No use of widgets.  2GB memory on a 3Ghz machine with XP Pro SP3 and current updates to all MS software, using VWD 2005 express for localhost functioning.  DNN 5.1 was a fresh install using install package, no use of the starter kits.

I don't know if this is anything that can be addressed by DNN, or if it is something that Microsoft would have to address as a performance issue with IE8, and honestly I have no idea what is going on behind the scenes that might be causing this issue to know what is to blame.  I don't see anything that IE8 has actually fixed or improved over IE7 in terms of rendering html, and have really only noted additional bugs and quirks being introduced by IE8.  You'd think the goal would be to solve issues, not add to the list, but then again it is MS and IE we are talking about... 

Anyone else notice this, or is this something specific to my setup/computer?

JOHN GIESY
DotNetNuke Hosting Expert

DotNetNuke 7 Hosting $70 /year
DNN4Less.com Team DotNetNuke  

Rick,

I haven't noticed this behaviour yet, but I am not running DNN 5 on any of our production sites atm.

I assume, you tried the same site with different browsers and same or comparable sites in differeint DNN versions? Are you able to compare 5.1 over 5.0 or did you compare with 4.9 only? are you using same cache settings and modules? There have been a number of changes in DNN 5.0 and 5.1 which might affect performance in specific constellations. Please make sure, you test same situation with the different DNN versions and report the precise setup to provide the developers with necessary information to narrow down the cause of the issue. thank you.

Rick,

there might be an issue with latest version of web controls, which are included with DNN 5.1 AFAIK. they might unnecessarily render an action menu per module or sth like this, we need to investigate. please log the issue into the public tracker at support.dotnetnuke.com. thank you.