Memory hierarchy from fastest to slowest, with examples.

Memory hierarchy from fastest to slowest, with examples.

• A. RAM → L1/L2/L3 cache → SSD → HDD → archival storage
• B. RAM → SSD → HDD → archival storage → L1 cache
• C. L1/L2/L3 cache → RAM → SSD → HDD → archival storage
• D. HDD → SSD → RAM → L1 cache

Answer: (C)

The concept being tested is how memory speeds form a hierarchy from fastest to slowest. The fastest layer is the on‑chip caches (L1, L2, and L3). These caches sit very close to the CPU and use SRAM, delivering ultra-low latency to keep the processor fed with data and instructions. Next is RAM, the system’s main memory, which is larger but slower than cache because it uses DRAM. Then comes SSDs, which store data in flash memory and have no moving parts, giving much quicker access than spinning disks. After that are hard disk drives, which rely on spinning platters and mechanical heads; they are slower due to seeks and rotational latency. Finally, archival storage is designed for long‑term retention and tends to be offline or near‑offline, with very high access times. So the order from fastest to slowest naturally follows: caches → RAM → SSD → HDD → archival storage.

The concept being tested is how memory speeds form a hierarchy from fastest to slowest. The fastest layer is the on‑chip caches (L1, L2, and L3). These caches sit very close to the CPU and use SRAM, delivering ultra-low latency to keep the processor fed with data and instructions. Next is RAM, the system’s main memory, which is larger but slower than cache because it uses DRAM. Then comes SSDs, which store data in flash memory and have no moving parts, giving much quicker access than spinning disks. After that are hard disk drives, which rely on spinning platters and mechanical heads; they are slower due to seeks and rotational latency. Finally, archival storage is designed for long‑term retention and tends to be offline or near‑offline, with very high access times. So the order from fastest to slowest naturally follows: caches → RAM → SSD → HDD → archival storage.