Full marks6/6
The computers need RAM because of the von Neumann stored program concept, in which the instructions of a program and the data it uses are both held in main memory. When a student opens a program on one of the new computers, the operating system copies it from the hard drive into RAM. The CPU then fetches each instruction from RAM in the fetch-decode-execute cycle, so the program must be in RAM before it can be run. The CPU cannot execute a program directly from secondary storage because a hard disk drive is much slower than RAM. It has moving parts and a much lower transfer rate, so the CPU would often have nothing to do while it waited for the next instruction. RAM is fast electronic memory that the CPU can read directly, which is why 16 GB of RAM lets the school run several programs at once and still keep the CPU working at full speed.
Why: Comprehensive understanding: the stored program concept is explained (instructions and data held in main memory), the program being opened is linked to it, and the speed difference is developed with the reason that the CPU would wait for instructions, all applied to the school's computers. Level 3.
Some marks2/6
RAM is the main memory of the computer. It stores the programs and data that are being used at the moment. When you open a program it is copied into RAM, and the CPU fetches instructions from RAM. RAM is faster than the hard drive, so a program runs better from RAM. Having 16 GB means the school can have more programs open at once.
Why: Basic, independent points only: what RAM is, that a program is copied into RAM when it is opened, that the CPU fetches instructions from RAM, and that RAM is faster than a hard drive. None is linked to the stored program concept or developed to explain why the CPU would have to wait for instructions, so Level 1, 2 marks.
No marks0/6
RAM is the permanent storage inside the computer, like a hard drive. The school needs 16 GB of RAM so that all the students' files can be saved permanently. When a program is opened, it is copied from RAM to the CPU. The CPU cannot execute from secondary storage because secondary storage is read-only.
Why: No creditworthy points. RAM is described as permanent storage, files are said to be saved permanently in RAM, a program is said to be copied from RAM to the CPU, and secondary storage is said to be read-only. All are the misconceptions listed in the Do not accept guidance, so Level 0.