Memory Hierarchy

Understanding Computer Hardware: From Microprocessors to Memory Computer hardware is the set of physical parts that let a device run. It includes the brain, memory, storage, and the parts that move data around. Knowing how these pieces fit helps you compare devices and understand why a system feels fast or slow. The brain of the machine: microprocessors and CPUs The central processing unit, or CPU, is the main chip that performs instructions. It follows steps, makes decisions, and guides other parts of the computer. Modern CPUs have multiple cores, and each core can work on several tasks at once (threads). The faster the clock, the more operations a core can do each second, but real speed depends on design, cache, and memory. ...

Memory Management in Modern OSes: Paging and Caches Modern operating systems use two ideas to manage memory: paging and caches. Paging divides the program’s memory into small blocks called pages and maps them to physical memory. Caches sit closer to the CPU and keep recently used data ready. Together, paging and caches help keep programs safe, fast, and responsive. Paging basics are simple in concept. A process sees a virtual address space, split into pages. The OS stores a page table that translates each page number to a physical frame in RAM. Each page table entry carries the frame number plus flags such as read/write access and whether the page is allowed for the current process. The hardware uses a translation lookaside buffer, or TLB, to speed up these translations. When the CPU accesses data, the TLB check is quick; if the data is not there, a longer page table walk happens, and the translation is filled in. If the data is not in RAM, a page fault occurs. The operating system then loads the needed page from disk, updates the table, and restarts the access. ...

Memory Management Demystified: Paging, Segmentation, and Caching Memory management is how a computer keeps track of all active programs. It helps apps use memory safely and efficiently. Two common ideas are paging and segmentation. They turn a large, simple idea—virtual memory—into smaller pieces that fit the hardware. Understanding these basics helps you see why programs run smoothly most of the time and why they pause when memory is tight. Paging splits memory into fixed-size chunks called pages. The program sees a single, continuous address space, but the system stores pages in physical frames scattered across RAM. A page table records where each virtual page lives. When a page is needed and not in RAM, the system loads it from disk. That moment is a page fault, and the hardware plus the operating system handle the move. The result is a flexible system that uses RAM efficiently, even when many programs run at once. ...