> A bad memory layout can have a huge impact on perf. A simple example is iteration order of a 2d array, where not doing sequential access can result in a ~5x slow down.
I know all that stuff, but the presenter doesn’t talk about RAM layout of data structures. They talk about a few [kilo]bytes offset caused by differently sized environment variables, and layout differences caused by linking order.
> Only if you forgot to apply thermal paste.
Try benchmarking a single-threaded code in 2 cases, in cold state, and when the rest of the CPU cores are running something like CPU stress test (but not accessing IO or L3 cache, i.e. not directly consuming any shared resources). You will easily get above 40% difference, despite the thermal paste.
I know all that stuff, but the presenter doesn’t talk about RAM layout of data structures. They talk about a few [kilo]bytes offset caused by differently sized environment variables, and layout differences caused by linking order.
> Only if you forgot to apply thermal paste.
Try benchmarking a single-threaded code in 2 cases, in cold state, and when the rest of the CPU cores are running something like CPU stress test (but not accessing IO or L3 cache, i.e. not directly consuming any shared resources). You will easily get above 40% difference, despite the thermal paste.