# Day 15 Casey decides to restrict File IO to 32 bit limits for file size (under 4 gigs). This is due to a limitation do the win32 API in how much it can read into a provided buffer to `ReadFile` by the size of DWORD (4-bytes). For the purposes of this engine and problably almost all applications this is alright. IF somehow more is needed, just reading in chunks of 4 gigs at a time is fine. I ended up watching a vod earlier recommended: Mysteries of Memory Management Revealed,with Mark Russinovich [Part 1](https://www.youtube.com/watch?v=TrFEgHr72Yg&t) [Part 2](https://www.youtube.com/watch?v=RsQyc4xiJeo) Was really nice, I got some of the equivalent info for linux.