Got myself a few months ago into the optimization rabbit hole as I had a slow quant finance library to take care of, and for now my most successful optimizations are using local memory allocators (see my C++ post, I also played with mimalloc which helped but custom local memory allocators are even better) and rethinking class layouts in a more “data-oriented” way (mostly going from array-of-structs to struct-of-arrays layouts whenever it’s more advantageous to do so, see for example this talk).

What are some of your preferred optimizations that yielded sizeable gains in speed and/or memory usage? I realize that many optimizations aren’t necessarily specific to any given language so I’m asking in !programming@programming.dev.

  • Mikina@programming.dev
    17·
    1 year ago

    I was working on a pretty well known game, porting it to consoles.

    On PS4 we started getting OOM crashes after you’ve played a few levels, because PS4 doesn’t have that much memory. I was mostly new on the project and didn’t know it very well, so I started profiling.

    It turned out that all the levels are saved in a pretty descriptive JSON files. And all of them are in Unity’s Scriptable Objects, so even if you are not playing that level, they all get loaded into memory, since once something references a SO, it gets loaded immediately. It was 1.7Gb of JSON strings loaded into memory once the game started, that stays there for the whole gameplay.

    I wrote a build script that compresses the JSON strings using gzip, and then uncompresses it when loading the actual level.

    It reduced the memory of all the levels to 46Mb down from 1.7Gb, while also reduced the game load by around 5 seconds.