Spectre Mitigation Performance Impact For Intel's Rocket Lake

One of the main real-world areas most significantly still impacted by these mitigations are the web browsers. Here is a look at that difference with Firefox and Google Chrome:

The browser benchmarks for JavaScript-heavy tests tend to still show a sizable performance difference when these Spectre mitigtions are in place. Granted, with Rocket Lake having just been launched, the "default" performance is the out-of-the-box / expected state and not a performance hit introduced post-launch like with the older Intel CPUs when Spectre (and Meltdown, etc) first came to light. The results show though there still is a sizable difference if disabling these mitigations. Some users have run mitigtions=off in production in the name of performance and believing the JavaScript-based exploits were hypothetical, but Google recently did show a Spectre browser-based exploit in action.