After several months of intense research, helped along by literally hundreds of reader suggestions, Betanews has revised and updated its testing suite for Windows-based Web browser performance. The result is the Comprehensive Relative Performance Index (CRPI). If it’s “creepy” to you, that’s fine.
We’ve kept one very important element of our testing from the very beginning: We take a slow Web browser that you might not be using much anymore, and we pick on its sorry self as our test subject. We base our index on the assessed speed of Microsoft Internet Explorer 7 on Windows Vista SP2 — the slowest browser still in common use. For every test in the suite, we give IE7 a 1.0 score. Then we combine the test scores to derive a CRPI index number that, in our estimate, best represents the relative performance of each browser compared to IE7. So for example, if a browser gets a score of 6.5, we believe that once you take every important factor into account, that browser provides 650% the performance of IE7.
As you’ll see, we believe that “performance” means doing the complete job of providing rendering and functionality the way you expect, and the way Web developers expect. So we combine speed, computational efficiency, and standards compliance tests. This way, a browser with a 6.5 score can be thought of as doing the job more than five times faster and better.
Here now are the eight batteries we use for our suite, and how we’ve modified them where necessary to suit our purposes:
Here’s how we developed our new score for this test: There are three loading events: one for Document Object Model (DOM) availability, one for first element access, and the third being the conventional onLoad event. We counted DOM load as one sixth, first access as two sixths, and onLoad as three sixths of the rendering score. Then we adjusted the re-rendering part of the test so that it iterates 50 times instead of just five. This is because some browsers do not count milliseconds properly in some platforms — this is the reason why Opera mysteriously mis-reported its own speed in Windows XP as slower than it was. (Opera users everywhere…you were right, and we thank you for your persistence.) By running the test for 10 iterations for five loops, we can get a more accurate estimate of the average time for each iteration because the millisecond timer will have updated correctly. The element loading and re-rendering scores are averaged together for a new and revised cumulative score — one which readers will discover is much fairer to both Opera and Safari than our previous version.
Next: The additions and changes we’ve made…
The additions and changes we’ve made to our performance index
Each heat produces a set of five results: total elapsed time, the amount of that time spent actually rendering the cube, the average time each loop takes during rendering, and the elapsed time in milliseconds of the fastest and slowest loop. We add those last two together to obtain a single average, which is compared with the other three times against scores in IE7 to yield a comparative index score.
- Nontroppo table rendering test. As has already been proven in the field, CSS is the better platform for rendering complex pages using magazine-style layout. Still, a great many of the world’s Web pages continue to use HTML’s old <TABLE> element (created to render data in formal tables) for dividing pages into grids. We heard from you that if IE7 is still important (it is our index browser after all), old-style table rendering should still be tested. And we’ve decided to concur.
The creator of our CSS rendering test has created a similar platform for testing not only how long it takes a browser to render a huge table, but how soon the individual cells (<TD> elements) of that table are available for manipulation. When the test starts, it times the duration until the browser starts rendering the table and then ends that rendering, from the same mark, for two index scores. It also times the loading of the page, for a third index score. Then we have it re-render the contents of the table five times, and average the time elapsed for each one, for a fourth score. The four items are then averaged together for a cumulative score.
- Nontroppo standard browser load test. (That Nontroppo gets around, eh?) This may very well be the most generally boring test of the suite: It’s an extremely ordinary page with ordinary illustrations, followed by a block full of nested <DIV> elements. But it allows us to take away all the variable elements and concentrate on straight rendering and relative load times, especially when we launch the page locally. It produces document load time, document plus image load times, DOM load times, and first access times, all of which are compared to IE7 and averaged.
- Acid3 standards compliance test. The function of the Acid3 test has changed dramatically, especially as most of our browsers become fully compliant. IE7 only scored a 12% on the Acid3; but today, most of the alternative browsers are at 100% compliance, with Firefox at 93% and flirting with 94%. So it means less now than it did in earlier months to have Acid3 yield an index score of 8.33, which is the score for any browser that scores 100% thanks to IE7. Now that cumulative index scores are closer to 20, having an eight-and-a-third in the mix has become a deadweight rather than a reward.
The physical test platform we’ve chosen for our tests is a triple-boot system, which enables us to boot different Windows versions from the same large hard drive. Our platforms are Windows XP Professional SP3, Windows Vista Ultimate SP2, and Windows 7 Release Candidate.
All platforms are always brought up to date using the latest Windows updates from Microsoft, prior to testing. We realize, as some have told us, that this could alter the speed of the underlying platform. However, we expect real-world users to be making the same changes, rather than continuing to use unpatched and outdated software. Certainly the whole point of testing Web browsers on a continual basis is because folks want to know how Web browsers are evolving, and to what degree, on as close to real-time a scale as possible. When we update Vista, we re-test IE7 on that platform to ensure that all index scores are relative to the most recent available performance, even of that aging browser on that old platform.
The physical test unit is an Intel Core 2 Quad Q6600-based computer using a Gigabyte GA-965P-DS3 motherboard, an Nvidia 8600 GTS-series video card, 3 GB of DDR2 DRAM, and a 640 GB Seagate Barracuda 7200.11 hard drive (among others). Three Windows XP SP3, Vista SP2, and Windows 7 RC partitions are all on this drive. Since May 2009, we’ve been using a physical platform for browser testing, replacing the virtual test platforms we had been using up to that time. Although there are a few more steps required to manage testing on a physical platform, you’ve told us you believe the results of physical tests will be more reliable and accurate.