Significant GC performance penalty

[Peter Alexander]

Allocating memory is simply slow. The same is true in C++ where 
you will see performance hits if you allocate memory too often. 
The GC makes things worse, but if you really care about 
performance then you'll avoid allocating memory so often.

Try to pre-allocate as much as possible, and use the stack 
instead of the heap where possible. Fixed size arrays and structs 
are your friend.

I avoid using the GC when using D and I feel like I still have a 
lot of freedom of expression, but maybe I'm just used to it.