I do entirely expect SBCL to come within factor of 2 to C (if you instrument your Lisp code with type declarations properly), and definitely to get JVM performance. And even unoptimized CL code I expect to run faster than Ruby, Python or JS.
Modern CL implementations are good, and the language itself gives you plenty of ways to help the program compile down to efficient native code.
I do entirely expect SBCL to come within factor of 2 to C (if you instrument your Lisp code with type declarations properly), and definitely to get JVM performance. And even unoptimized CL code I expect to run faster than Ruby, Python or JS.
Modern CL implementations are good, and the language itself gives you plenty of ways to help the program compile down to efficient native code.