The primary advantage or objective of Virtual Memory systems is the ability to load and execute a process that requires a larger amount of memory than what is available by loading the process in parts and then executing them.  The disadvantage is that Virtual Memory systems tend to be slow and require additional support from the system's hardware for address translations.  It can be said that the execution speed of a process in a Virtual Memory system can equal, but never exceed, the execution speed of the same process with Virtual Memory turned off.  Hence, we do not have an advantage with respect to the execution speed of the process.  The advantage lies in the ability of the system to eliminate external fragmentation.  The other disadvantage of Virtual Memory systems is the possibility of Thrashing due to excessive Paging and Page faults.  In may be noted that Trash Point is a point after which the execution of a process comes to a halt; the system is busier paging pages in and out of the memory than executing them.