Featured Articles

Analysts expect ARM to do well next year

Analysts expect ARM to do well next year

British chip designer ARM could cash in on the mobile industry's rush to transition to 64-bit operating systems and hardware.

More...
Huawei and Xiaomi outpace Lenovo, LG in smartphone market

Huawei and Xiaomi outpace Lenovo, LG in smartphone market

Samsung has lost smartphone market share, ending the quarter on a low note and Xiaomi appears to be the big winner.

More...
Intel Broadwell 15W coming to CES

Intel Broadwell 15W coming to CES

It looks like Intel will be showing off its 14nm processors, codenames Broadwell, in a couple of weeks at CES 2015.

More...
Gainward GTX 980 Phantom reviewed

Gainward GTX 980 Phantom reviewed

Today we’ll be taking a closer look at the recently introduced Gainward GTX 980 4GB with the company’s trademark Phantom cooler.

More...
Zotac ZBOX Sphere OI520 barebones vs Sphere Plus review

Zotac ZBOX Sphere OI520 barebones vs Sphere Plus review

Zotac has been in the nettop and mini-PC space for more than four years now and it has managed to carve…

More...
Frontpage Slideshow | Copyright © 2006-2010 orks, a business unit of Nuevvo Webware Ltd.
Friday, 19 November 2010 10:25

Microsoft “cheats” at benchmark test

Written by Nick Farell
ie

Feature in IE allows superspeeds to be recorded
A bug in Microsoft's Internet Exploder 9 appears to have the advantage that it allows the browser to sale through the SunSpider JavaScript performance benchmark. The benchmark was devised by the developers of the WebKit browser engine, is used and quoted widely as a measure of browser scripting performance.

IE 9 did extremely well in the test and this had people scratching their heads a bit. One of them Mozilla developer, Rob Sayre, made some minor changes to the test and saw Internet Explorer 9 slow down considerably. He filed a bug against Internet Explorer.

Sayre suggested that an optimization that Internet Explorer 9's Chakra JavaScript engine was performing was fragile. It was easily disabled by minor alterations to the code that it should ignore.

Some more cynical hacks claimed that Redmond must have done it all deliberately and that Internet Explorer 9 had been designed to cheat in the test. The allegation is that Microsoft has built a specific optimisation into Chakra that detects, and bypasses, the specific code in SunSpider, but which has no other purpose.

Such things have been done before, but Ars Technica thinks that was what happened here. It thinks that the benchmark has dead code under the bonnet. This is the kind of code that can be reached and executed, but whose results are never used. Sometimes this code is ignored by a compiler.

SunSpider has a test which computes the sine and cosine of a number using a CORDIC algorithm. JavaScript contains built-in sine and cosine functionality, functionality that will be much faster than performing the computation in this way, so it is not something real programs would ever do. The test does not bother using the results that it has computed and as a result the entire test susceptible to dead code elimination.

Internet Explorer 9 accurately treats the entire test as dead code, and so removes the whole lot. This makes for a very fast benchmark result. Actually this is a good thing, as it means that IE 9 is capable of ignoring a lot of dead code. However it does boost the performance figures a bit too much.

Nick Farell

E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
blog comments powered by Disqus

 

Facebook activity

Latest Commented Articles

Recent Comments