In our case, the /DEBUG binary is 50% larger, the binary built with /DEBUG /OPT:REF is still 40% larger. From the answers in Visual Studio: debug information in release build I expected a release build with debug information shouldn't be that much larger. What are we missing?
This is one major reason why we're currently shipping the stripped binary, instead of one that's easy to debug. I'm not the build master, so please bear with me.
Sizes:
22MB with /O2
35MB with /O2 /DEBUG
32MB with /O2 /DEBUG /OPT:REF