[cpp.speed] Speed

Since Java is run from bytecode that will execute on any machine, it is slower.  

However unless an application needs to do a large amount of number crunching, it will spend most of its time waiting for I/O, waiting for a database query to return, waiting for data over the network, waiting for the disk to respond, even waiting for memory.

Optimizations in the Java Virtual Machine and the Java compilers mean execution speeds are very fast, more than adequate for most purposes.