Caches

How Modern Hardware Shapes Software Performance Today, software performance is not just about faster clocks. Modern hardware shapes behavior at every layer, from the CPU to the storage stack. If you want predictable apps, you must consider how data moves through caches and memory, and how the processor schedules work. This awareness helps you write code that scales in real systems. Cores, caches, and memory hierarchy determine the baseline performance. L1, L2, and L3 caches keep hot data close to execution units. A hit is fast; a miss can stall for dozens of cycles and trigger a longer memory fetch from main memory or from remote NUMA nodes. Writing cache-friendly code and organizing data to stay in caches can deliver big gains without visible hardware changes. ...

Performance Tuning for Databases Performance tuning for databases helps keep apps fast as data grows. Start with clear goals: lower end-to-end latency, higher throughput, and predictable response times during peak load. Measure first. Collect baseline metrics: average query latency, 95th percentile, queries per second, CPU and memory use, and I/O wait. Use dashboards and logs to watch trends. With solid data, you can see what improves performance and what does not. ...

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. ...