The content on my blog is pretty static, in particular the images do not change that often...if at all. So why does IE need to check to see if an image has changed every time a new page is loaded?
My blog site had slowed down considerably since I added the images for the different flags...all because IE was checking every image to see if it had changed before displaying it.
A quick change to the IIS Application improved the performance of the blog no end. I simply added a cache-control directive to the response headers...
cache-control: max-age=3600, no-check
This increases the max to 1h (3600 seconds) from the 0 that is the default and instructs IE not to bother checking again (no-check). Other values include post-check & pre-check and are shown below...
More information abut this directive can be found on the Microsoft website.
You can modify the headers directly from the IIS administration console by selecting the properties of the application and choosing the HTTP Headers tab...
Here you can add your own custom headers...as shown above with the changes I made to my blog IIS site
If your site content is pretty static maybe your visitors could benefit from adding this header, which should improve the user experience and reduce the server load.