<story><title>Actual JavaScript Engine Performance</title><url>http://crockford.com/javascript/performance.html</url></story><parent_chain></parent_chain><comment><author>daleharvey</author><text>If I was trying to think of something less representative of large well written javascript application I would have a hard time thinking of something better than JSLint.&lt;p&gt;It doesnt touch the dom, is not event driven, doesnt involve loading lots of files and does not render anything</text></comment>
<story><title>Actual JavaScript Engine Performance</title><url>http://crockford.com/javascript/performance.html</url></story><parent_chain></parent_chain><comment><author>hoppipolla</author><text>It is worth taking this with a liberal sprinkling of salt.&lt;p&gt;The first problem is that there is no documentation of method. It appears that the results were obtained by simply running JSLint on itself once. Without some indication of how the results are obtained and how stable they are it is essentially meaningless. Of course this is quite fixable but until it is fixed the data presented is basically worthless.&lt;p&gt;The second, and arguably larger, problem is that the page makes grandiose claims about the applicability of the benchmark that it doesn&apos;t even attempt to back up. In particular the claim that the performance on JSLint will be a better proxy for &quot;other large, well-written JavaScript applications&quot; than existing benchmarks. If we examine the Microsoft paper linked, it says:&lt;p&gt;&quot;Specific common behaviors of real web sites that are underemphasized in the benchmarks include event-driven execution, instruction mix similarity, cold-code dominance, and the prevalence of short functions&quot;&lt;p&gt;It is not demonstrated, nor is it obviously apparent, that JSLint will be any more typical in these respects than other benchmarks. I haven&apos;t examined the JSLint source code but I assume it isn&apos;t event-driven, deals mainly with string manipulation and makes many calls to the same few functions during parsing. If my guesses are correct it sounds like it will not, on its own, be a significantly better proxy for real-world performance than existing benchmarks. Of course it may be that it exercises a different subset of the ECMAScript engine than existing benchmarks; in this case a test like this would be a good addition to, rather than replacement for, an existing benchmark suite.</text></comment>