Real world sample of why sanity testing is important 28. August 2014 Marius-Gheorghe development (0) Here's a very interesting real world sample of why simple sanity tests before a release are important. Metro 2033 Redux and Metro Last Light Redux have just been released with a giant bug (both games crash right at startup). Apparently they only crash on CPUs who do not support SSE 4.1 (most likely the "bug" is because they compiled with very aggressive optimizations and a +SSE4.1 instruction is generated). Obviously they would have found this big problem just by running the game on multiple machines with different configurations.