CPU cache

<p>A CPU cache is a <a href="/facts/Hardware_cache/gmJYN8wm">hardware cache</a> used by the <a href="/facts/Central_processing_unit/Jxp1bqMV">central processing unit</a> (CPU) of a <a href="/facts/Computer/SQe1aK05">computer</a> to reduce the average cost (time or energy) to access <a href="/facts/Data_(computer_science)/cPjfFHph">data</a> from the <a href="/facts/Main_memory/wPHKFpdx">main memory</a>. A cache is a smaller, faster memory, located closer to a <a href="/facts/Processor_core/Jxp1bqMV">processor core</a>, which stores copies of the data from frequently used main <a href="/facts/Memory_location/7EsUmbea">memory locations</a>. Most CPUs have a hierarchy of multiple cache levels (L1, L2, often L3, and rarely even L4), with different instruction-specific and data-specific caches at level 1. The cache memory is typically implemented with <a href="/facts/Static_random-access_memory/Pmyo4V5e">static random-access memory</a> (SRAM), in modern CPUs by far the largest part of them by chip area, but SRAM is not always used for all levels (of I- or D-cache), or even any level, sometimes some latter or all levels are implemented with <a href="/facts/EDRAM/rf8jR3Ds">eDRAM</a>.
</p><p>Other types of caches exist (that are not counted towards the "cache size" of the most important caches mentioned above), such as the <a href="/facts/Translation_lookaside_buffer/vvwGkfvD">translation lookaside buffer</a> (TLB) which is part of the <a href="/facts/Memory_management_unit/tJQtAQzI">memory management unit</a> (MMU) which most CPUs have.
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CPU cache open-in-new

CPU cache