> I wonder why startup speed in V8 is slow though, AFAIK it doesn't do AOT compilation, or is this now the case with the new Turbofan module? Correct, Turbofan

> I wonder why startup speed in V8 is slow though, AFAIK it doesn't do AOT compilation, or is this now the case with the new Turbofan module? Correct, Turbofan does a lot more up-front compilation for asm.js. There is also work in v8 to do full asm.js validation and AOT using that info, https://bugs.chromium.org/p/v8/issues/detail?id=4203 https://bugs.chromium.org/p/v8/issues/detail?id=4203 > I wonder if pre-allocating a large chunk of memory is still as much an issue in 64-bit browsers as with 32-bit. On 64-bit it's mostly a non-issue, yeah, you can allocate a single 1GB+ chunk fairly easily. There have also been big improvements on 32-bit Chrome over the last year, https://code.google.com/p/chromium/issues/detail?id=394591 https://code.google.com/p/chromium/issues/detail?id=394591 https://code.google.com/p/chromium/issues/detail?id=533580 https://code.google.com/p/chromium/issues/detail?id=533580 But again, this is mostly a non-issue on 64-bit, and 64-bit is rapidly becoming the norm anyhow.