What is the Cost?

Examples 2 and 3 in the examples directory demonstrate the two alternative methods. Both perform the same function: reading a data file and filling one histogram. Example 2 is a SNOMAN application, whereas example 3 is a SNOlib application that does not use SU control. The following table shows the costs of building the applications and running them on a file of 100 events using an ALPHA 3000/OpenVMS:-

Operation          Example 2  Example 3 




Link time CPU (sec) 		  7.9 		  2.5      


Link time elapse (sec) 		  65 		  26       




Execution file size (Mbytes) 		  3.4 		  0.9      




Run time CPU (sec) 		  33.3 		  30.0     


Run time elapse (sec) 		  80 		  79       


Run time virtual mem (Mbytes) 		  26.7 		  23.3     

So the cost is a longer linking time, some wasted virtual address space and a slight drop in performance. However the benefit is the ability to treat SUs in a very simple manner, not needing to know the details of initialisation, reinitialisation after titles update, termination or their interdependencies.