Google recently rolled out Chrome 67 and one of the new features in that release was Site Isolation, a technique that limits each renderer process to documents from a single page. This mitigation technique makes it more difficult for attackers to perform Spectre-like speculative execution exploits.
Unfortunately, the extra protection comes at a cost. Google Chrome team member Charlie Reis reveals the new security features will increase RAM consumption by an extra 10 to 13 percent:
All this sounds good, but it comes at a cost. Reis highlighted that Site Isolation will chow down on an extra 10 to 13 per cent total memory overhead in "real workloads", basically making the Chrome browser an even bigger memory hog than it already is. But Reis did say Google is working on optimising Chrome to it keeps its security but runs fast.