Updates to Add-on Performance Advisor

March 23rd, 2011

The Add-on Performance Advisor helps you stay in control of your browsing experience with add-ons. Since we introduced this feature in IE9 Beta, the positive and constructive feedback you provided enabled us to adjust the functionality while maintaining its original goals. You can experience these changes in action with the final release of IE9.

In this post, we review the issues users face today with add-on performance and the benefits offered with this feature. We describe the rationale behind the key changes we made and show how they improve the user experience and more accurately measure add-on performance. Along the way, we address some frequently asked questions on the feature’s functionality.

Recap: Add-ons and Performance

Add-ons can have a material impact on browsing performance, most notably in the following activities:

  • Opening a New Tab
    Every time you open a new tab or browsing window, IE initializes your add-ons. The time it takes each add-on to initialize is its load time.
  • Navigating to Web pages
    Every time you visit a Web page, your add-ons can perform operations on the page, such as adding icons next to search results or scanning links to identify phishing sites. The time it takes an add-on to perform these operations for each navigate is its navigation time.

Many users have multiple add-ons installed and running in their browsers. The cumulative performance impact of all these add-ons affects the overall experience of browsing and viewing a Web site.

While we work with add-on developers to improve add-on performance, it’s important for you to understand add-ons’ performance impact and how to manage them. The Add-on Performance Advisor monitors add-on performance and notifies you only when your add-ons are noticeably slowing down your browsing experience. You can choose to use only the add-ons you want while maintaining browsing performance.

Accurately Measuring Add-on Performance

We made two changes to our add-on performance measurement algorithms since IE9 Beta:

  • IE no longer records the first load time for all add-ons after upgrading to IE9
  • IE no longer records an add-on’s first load time after it is installed and enabled for use in IE9

Here’s a brief explanation of the change. While analyzing the load times for 15 of the most popular add-ons in IE8 we found that the average add-on load time in the above two scenarios were notably higher than the average load time during regular browsing:

Load Time Measurement Scenario Average Load Time (milliseconds)
Launch IE9 regularly 37
IE9 first run after upgrade 399
Add-on first run after it is enabled in IE9 300

This difference in load time exists because add-ons typically perform more operations when launched for the first time. Additionally, since IE takes longer to launch for the first time, it shares system resources with add-ons and will increase add-on load times.

It’s important that we measure an add-on’s load time accurately and consistently so that you can make the right decisions on your add-ons. We decided not to record load times in the above two scenarios with this goal in mind.

For example, in IE9 Beta you may prematurely disable an add-on that you like because its first load time is notably higher and triggers the Add-on Performance notification. With the current functionality, we will show the Add-on Performance notification only if we continue to measure high load times for that add-on.

Evolving Notifications

We received lots of good feedback regarding the design of the Add-on Performance notification since Beta. We’ve since refined the design for the final IE9 release.

We updated the notification message and added an option in the dropdown menu for the “Ask me later” button.

If you are satisfied with your add-on performance even though it is above your desired threshold, you can select the “Don’t disable” option to turn off the Add-on Performance notification for 30 days. If you prefer not to make a decision on your add-ons yet, you can select the “Ask me later” option which only turns off the notification for 1 day.

Once you install and enable a new add-on, IE will turn the Add-on Performance notification back on since the new add-on may impact browsing performance beyond your previously desired levels.

When multiple new add-ons are installed, we made it clearer to users that they can choose which ones to enable.

Choose Add-ons Dialog

You can launch the Choose Add-ons dialog via both the above notifications. When it’s launched from the Add-on Performance notification, we show the following variation of the dialog.

Some of you asked how IE decides which color is used to display the bars in the above dialog. Our intention is to use the colors to indicate the minimum number of add-ons that need to be disabled so that you can stay below the threshold. In the above dialog, disabling the Contoso and Litware toolbars, which have red bars, leaves you with 0.04 seconds of total load time.

You may decide to only use the Contoso Toolbar. If you disable all the other add-ons, we’ll display a grey bar for the Contoso Toolbar indicating that you’re now below the threshold. Similarly, you can change the default threshold to 0.50 seconds and all the above add-ons will have grey bars displayed.

Notice that we lengthened the default height of the above dialog to accommodate 6 add-ons before requiring you to scroll. This helps you make the most informed decision on which add-ons to use since you can view the performance impact of more add-ons at one glance. We also added a confirmation dialog when you press “Disable All” so that you don’t accidentally disable all your add-ons

Thanks for Your Feedback

The feedback you’ve given us on the Add-on Performance Advisor since IE9 Beta allowed us to improve the overall user experience and add-on performance measurement accuracy.

In a future post, we’ll blog more about add-on performance and how the ecosystem has evolved since we started the conversation around measuring and improving performance. We’ll continue to engage with add-on developers on improving add-on performance through blog posts and other efforts. The ideal experience is one where you can use as many add-ons as you want without compromising browsing performance (and reliability, security, and privacy).

—Herman Ng, Program Manager, Internet Explorer