Benefits of 'Optimize code' option in Visual Studio build

Question

Much of our C# release code is built with the \'Optimize code\' option turned off. I believe this is to allow code built in Release mode to be debugged more easily.

Answer 1

I find that with complex, CPU intensive code (the code i'm using is a Monte Carlo simulation that can spawn enough threads to 100% utilize a computer. This was tested in a 36 core environment) the performance hit can be up to 4 times higher! A simulation that takes 2 hours will take about 9 hours without the optimization flag. (the paths are about 500,000 and for each paths there are 500 steps for around 2000 different objects with highly complex calculation on each objects).