You're missing the point. The current optimized-for-normal-javascript Chrome takes a 6x hit on asm.js code, compared to odinmonkey. That's kind-of crappy but it's not a killer, and it could get asmjs support (maybe, who knows). The fear I was talking about was browsers which are already much slower than Chrome , and have no chance in hell of ever getting asmjs support, hence the mention of IE6.
Who said Chrome gets a 6x perf hit?
You just have the numbers with asm.js.
If Chrome hasn't been optimized for asm.js style code, then those numbers would either be what Chrome already achieves with JS (e.g plain old V8 speed), or slightly faster than regular JS (because of the more streamlined, easy to JIT nicely asm code).