Why Do I need Econo JIT?

Question

I studied that Econo JIT is not optimized for the environment compiling the IL, different than the Normal JIT. Also, it doesn't create machine code cache for the next execution, which means every time the PE runs, the JIT compiles the IL into machine instructions again.

I am confused why would One choose to compile in Econo Jit then. Also, is there a choice of JIT to be chosen in Visual Studio? or should I compile through prompt if I want to choose difference JIT mode?

Answer 1

The idea of Econo JIT is to spend less time compiling so that startup latency is lower for interactive applications. This is actually what you want once you notice the app takes seconds to start up. .NET startup time is increadibly slow already (so is Java's :) ).

In server-side apps you want the opposite: You want perfect code and are willing to wait because you probably warm-up your app anyway before connecting it to the load-balancer. You issue an automatic GET to the homepage and other important pages to get them loaded and compiled.

AFAIK Econo JIT is obsolete since .NET 2.0. There is no choice anymore (except for disabling all optimizations which is the nuclear bomb option).