Memory Efficiency Benchmarks
Internet Explorer 8 uses the least memory, overall, in our single-tab measurement (49 MB) and a full 40-tab load (420 MB). Chrome, Firefox, and Opera end up in a three-way tie for second place in single-tab usage, all three eating up roughly 60 MB. Safari uses the most RAM to display one tab (93 MB). Chrome holds onto second place with 40 tabs up, consuming just under 460 MB. Firefox places third, while Safari takes fourth place. Opera soars to 620 MB with 40 tabs loaded, falling to last place.
Chrome takes the lead for memory management, dropping to just 92 MB after two minutes with 39 of the 40 tabs closed. Firefox places second at 150 MB, but takes considerably longer to release memory back to Windows than Chrome, IE8, or Safari. Third-place IE8 uses 227 MB after closing 39 of the 40-tab load, while Apple Safari holds onto 268 MB. Opera takes last place, monopolizing a lot of system memory even after we close 39 tabs and wait two minutes.
Chrome is the clear winner for memory efficiency on the older test system, and Firefox also keeps its consumption under control. While IE8 may not use the most memory under a load, its total doesn't drop substantially after closing 39 tabs. The same goes for Safari and Opera.
What raw memory measurements don't tell us is how the browsers perform with 40 tabs open.
Both IE8 and Safari froze for about 15 minutes after loading the full array of 40 tabs. Meanwhile, Firefox and especially Chrome and Opera remained fluid and responsive under the torture test. Although we don't have a benchmark for this, we definitely have to keep responsiveness in mind when it comes to our final analysis. Even though IE8 demonstrates low memory usage and respectable memory management traits, locking up for 15 minutes is an unforgivable artifact. The same goes for Safari.
Alternatively, even though Opera uses the most and releases the least memory, it gives us the most fluid heavy load experience out of the five browsers.