With SIMD, you always have to check what the compiler generates, you can't just write something and expect it to be vectorised. You are right about this but ev

With SIMD, you always have to check what the compiler generates, you can't just write something and expect it to be vectorised. You are right about this but everything else is far off. Modern software that runs slow on modern hardware has to be wildly inefficient to make a visible slow down. Even 'OO' programs that are doing lots of small allocations and skipping around in memory are lightning fast on 20 year old computers. Modern hardware is incredible. It's a testament to just how bad some software is that it runs slow. Most software can be sped up by 10x-100x by going from a scripting language to C++. Most software can be sped up 7x-100x after it is in C++ by weeding out excessive allocations and paying attention to memory access patterns. That's all before SIMD and multi-threading.