If you have a well-equipped computer, running Google Maps in all its glory will have little to no impact on your browser. However, try using Maps on a computer with limited resources and the performance of the website really suffers.
At this point, Google should take over and automatically switch you to Lite mode -- a slimmed down version of Maps that skips on features like 3D imagery and draggable routes in favor of a performance boost. But if the switch doesn't happen on its own, or you just want Maps to run a bit faster, you can enable it yourself. Here's how.
- Open Google Maps in your desktop Web browser.
- Click the lightning bolt in the bottom right-hand corner.
- Click Switch to Lite mode.
Note: If you don't see the lightning bolt, try clicking this link to activate it.
If you change your mind, you can click the lightning bolt again to switch back to the full mode of Google Maps.
You can find the complete list of features that were skipped in Lite mode on the Google Maps Help page.
(Via HowToGeek)