Minimizing the amount of malloc() calls improves performance?

Question

Consider two applications: one (num. 1) that invokes malloc() many times, and the other (num. 2) that invokes malloc() few times. Both applications allocate the same

Answer 1

You can always do a better job using malloc() to allocate a large chunk of memory and sub-dividing it yourself. Malloc() was optimized to work well in the general case and makes no assumptions whether or not you use threads or what the size of the program's allocations might be.

Whether it is a good idea to implement your own sub-allocator is a secondary question. It rarely is, explicit memory management is already hard enough. You rarely need another layer of code that can screw up and crash your program without any good way to debug it. Unless you are writing a debug allocator.