Memory Efficiency Benchmarks
We use the Internet's Top 40 Web sites (according to Quantcast) for our memory and page load reliability testing. Unlike our startup and page load times, this test uses live sites; the test sites are not hosted on our local Web server.
Chrome's memory usage is measured through its about:memory flag, while the other browsers are measured with the Windows Task Manager/Ubuntu System Monitor. Each browser is opened with the Google homepage as the only tab. Memory usage is recorded, and then the additional 39 tabs are loaded. Once all tabs report as loaded, we inspect each page for broken elements and reload any pages that have not opened properly before recording the 40-tab memory usage.
Next we close all tabs except the original one containing Google's homepage and re-record the memory totals. Finally, we wait two minutes and record the final memory usage figure.
IE9 is the least memory-hungry browser when only displaying one tab, consuming less than 30 MB. Firefox rolls into second place at roughly 63 MB. Safari is close behind in third place, using 65 MB. Opera falls to fourth, while Chrome takes last place.
In Ubuntu, Chrome uses the least amount of memory to display a single tab. Firefox places second, and Opera uses the most memory.
Safari moves into the top position after getting hit with 40 loaded tabs. Firefox is close behind in second place, while Opera places third. Chrome uses nearly 1.2 GB of memory, and Internet Explorer uses more than a gig and a half.
In Ubuntu, Firefox 10 takes the lead, using 662 MB (nearly 75 MB less than Safari's winning total in Windows 7). Opera places second, and Chrome comes in last place, using just under 1.5 GB.
After closing 39 of the 40 tabs, IE9 immediately approaches its pre-40-tab memory total of just 40 MB. Chrome drops down to 140 MB, taking second. Firefox is close behind in third place, while Safari trails behind in fourth. Opera places dead last at just over 450 MB.
In Ubuntu, Chrome takes the win at only 109 MB, beating its Windows 7 total. Firefox uses 666 MB in Linux, while Opera still hangs on to nearly 800 MB, both significantly higher than their Windows-based builds.
-39 Tabs + Two Minutes
After an additional two minutes, all five Windows-based browsers maintain the totals we've already seen.
In Ubuntu, Firefox drops down to only 155 MB, which still earns it second place. That's much better than Opera's 800 MB finish, though.
Overall, Internet Explorer and Chrome are the winners during periods of light usage. They also seem to manage memory best. Safari and Firefox shine more prominently during heavy loads. Chrome and IE9, however, are hogs when it comes to heavy use, and Opera for Linux demonstrates poor management.