9618 · 3.1
Common exam mistakes on 9618 Computers and their components. Learn what loses marks, then practise the topic with Examiner’s Ink.
Exam questions frequently ask you to compare and contrast two technologies, such as SSD and HDD. When answering, always structure your points around specific characteristics like speed, cost, capacity, durability, and power consumption. Use comparative words like 'faster', 'cheaper', 'higher', and 'more reliable'.
Think of it as your desk versus your filing cabinet. RAM is your desk: it's your working area where you keep things you're actively using. It's fast to access but limited in space, and when you're done for the day (power off), you clear it off (it's volatile). The SSD is your filing cabinet: it stores everything you own, whether you're using it or not. It's slower to access than your desk, but it has a huge capacity and keeps your files safe even when the power is off (it's non-volatile).
Even the fastest RAM is significantly slower than the CPU. If the CPU had to wait for RAM every single time it needed data, it would spend most of its time idle, creating a bottleneck. Cache is a smaller, much faster (and more expensive) type of memory that acts as a buffer between the CPU and RAM. It stores copies of the most frequently used data, so the CPU can access it almost instantly, leading to a massive performance increase.
Yes, but in a limited way. A computer needs an operating system to run, which is typically stored on an HDD or SSD. However, some systems can be booted from a network (known as a 'thin client') or a live USB/CD. In these cases, the OS is loaded into RAM from the external source. The computer would have no long-term storage once powered off, but it would be functional.
Almost all computers need a way to produce a visual output, but they don't all need a separate, dedicated GPU card. Many CPUs come with integrated graphics (an 'iGPU') built-in, which is sufficient for everyday tasks like web browsing and video playback. A dedicated GPU is a powerful, separate processor that is essential for demanding tasks like 3D gaming, video editing, and scientific computation.