tech's explination of the following

Stacks are used by the computer operating system to store the progression of program calls and values used for the calls. When a program repeatedly calls the same sequence of instructions , the instructions are usually placed into a sub program to save alot of waisted space and coding. The parent process will make a call to this subprogram and usually send values to this subprogram. All this is placed onto the stack (common area to all processes). Obviously if the stack space and or # of stacks is too few the system won't be able to allocate resources to handle the program(s).

Buffers on the other hand are reserved area's of memory for doing input and output of data to disk and other i/o devices like tape drives. Too few buffers can prevent program opperation due to not having a spare buffer when one is required. Too many buffers can restrict smooth program opperation

hope this helps
rick