JavaScript Performance Issues
Typically, up to 106 C instructions may be executed in a few milliseconds (the time it takes a person to notice anything!) as one instruction in 1 clock cycle (say 108/sec)
A Java interpreter is roughly 50 times slower than C
Java “Just-In-Time” compiler is roughly 2–8 times slower than C whereas a native Java Compiler (and perhaps future JIT’s) are about same speed as C
Perl is 500 times slower than C (an interpreter but analyses whole code before interpreting)
- Runtime (e.g. I/O) can be as fast as C as it is C!
Tcl, JavaScript (true interpreters) are up to 5000 times slower than C
- BUT If Java Script in browser invokes optimized C++ internal function, it can easily outperform Java
- Just as Java itself can of course invoke through JNI C++ code.
- Need C++ library to be built in as do not want to download