title: Optimisation , Compilers and Its Effects
body: <p>(i) If a Program is <strong>optimised</strong> for one CPU class (e.g. Multi-Core Core i7)
         by  <strong>compiling</strong> the Code on the same ,  then will its performance 
         be at sub-optimal level on other CPUs from older generations (e.g. Pentium 4)
         ... Optimizing may prove harmful for performance on other CPUs..? </p>
  
  <p>(ii)For optimization, compilers may  use x86 extensions (like SSE 4) which are
         not available in older CPUs.... so ,Is there a fall-back to some non-extensions
         based routine on older CPUs..? </p>
  
  <p>(iii)Is Intel C++ Compiler is more optimizing than Visual C++ Compiler or GCC..</p>
  
  <p>(iv) Will a truly Multi-Core Threaded application will perform effeciently on a 
         older CPUs (like Pentium III or 4)..?</p>