Most programmers write code for an abstract computer. The thing is- code runs on a real computer that works in a specific way. Even if your game is going to run on a wide range of devices, knowing some of the common features can speed up your code 10x or more. Today’s article shows you how!

Broadly, all modern computers have the same configuration. They have a CPU, a GPU, and RAM. The CPU also has two or three levels of cache: L1, L2, and L3. Those caches are used to speed up RAM access because it is so slow. Exact numbers will vary by device, but according to this site here are the rough speeds:

L1 cache access: 1 nanosecond
L2 cache access: 4 nanoseconds
RAM access: 100 nanoseconds
This means that there’s a 25-100x advantage to using the memory that’s in the CPU’s cache compared to memory that’s in RAM.