FCSCST1133Data Engineering Ecosystem

SCST1133 · Topic 01

Memory and Storage

Compare speed, capacity, volatility and persistence across the storage hierarchy.

01Introduction to Computer and System
Storage hierarchy

Not all storage serves the same purpose

Fast temporary memory and persistent storage work together to support system operation.

Hierarchy from CPU registers to cloud storage
Figure 5. Storage layers trade speed, capacity, persistence and cost.

Memory and storage comparison

ComponentPurposePersistence
RegistersImmediate values used by the CPUVolatile
CacheFrequently required instructions and dataVolatile
RAMActive programs and working dataVolatile
SSD/HDDLong-term local files and applicationsNon-volatile
Cloud storageRemote files available through a networkNon-volatile and network-dependent

Common misunderstanding

RAM is not the same as permanent storage. Increasing RAM may improve multitasking, but it does not automatically increase SSD capacity.