After spectre mitigations performance.now() not longer a hight resolution timer. This causes that the default settings of motionmark to give wrong results. Motion mark supports 3 methods to measure performance as you can see here at the bottom right http://browserbench.org/MotionMark/developer.html The default should be changed from performance.now() to one of the other methods.
perf.now() and rAF timestamp should be quantized the same way, and I think Date.now() will also be.
(In reply to Simon Fraser (smfr) from comment #1) > perf.now() and rAF timestamp should be quantized the same way, and I think > Date.now() will also be. That makes sense, actually. I have been testing motionmark with WPE trunk and I have been getting sometimes some weird results with the default settings (like 1 points on some tests with a +-3000% percent of variance). So, at first I thought it could be related to the spectre mitigations of performance.now() because I couldn't reproduce with the other methods of the benchmark like rAF. But I'm not able to reproduce this with a webkit build of last trunk on Mac. So it should be something else... I'm closing this as invalid, then. Thanks for the comments.