Updates to Add-on Performance Advisor

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

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:

Screen shot of notification bar asking to speed up browsing by disabling add-ons

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

Screen shot of "Ask me later" options in notification bar asking to speed up browsing by disabling add-ons

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:

Screen shot of notification bar indicating there are new add-ons ready for use

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:

Screen shot of the Choose Add-ons to disable dialog box

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:

Screen shot of confirmation alert shown when disabling all 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