Is L1 cache as fast as registers?

CPU register is always faster than the L1 cache. Воно найближче. The difference is roughly a factor of 3. Trying to make this as intuitive as possible without getting lost in the physics underlying the question: there is a simple correlation between speed and distance in electronics.24 Jan 2013

The fastest type of memory is the Регістри процесора, which are located within the CPU itself and provide the CPU with quick access to frequently used data. Next in terms of speed is Cache Memory, which is a small amount of high-speed memory located close to the CPU.

L1 cache is the smallest and fastest cache, often within 32 KiB to 64 KiB. It operates at the speed of the CPU itself. Each processor core usually has separate L1 caches for instructions and data. L2 cache, larger and slower than L1, is often shared between cores on a multi-core processor.

Comparing Cache Memory and Register Cache is a small, high-speed component of a computer system's memory. Registers are fast storage elements integrated into the computer's processor. Cache stores frequently accessed data of a computer. Registers store the data that the CPU is currently processing.

CPU can operate on register contents at the rate of more than one operation in one clock cycle. ЦП звертається до пам'яті з меншою швидкістю, ніж реєстр.

Кеш рівня 1 (L1): Це найменший і найшвидший тип кеш-пам'яті. Він вбудований безпосередньо в центральний процесор, що дозволяє йому працювати з тією ж швидкістю, що й центральний процесор. Кеш L1 зазвичай ділиться на дві частини: одна для зберігання інструкцій (L1i) і друга для зберігання даних (L1d).

Reading from register has 0 or 1 cycle latency. Writing to registers has 0 cycle latency. Кеш L1 читання/запису має затримку від 3 до 5 циклів (varies by architecture age) Actual load/store requests may execute within 0 or 1 cycles due to write-back buffer and store-forwarding features (details below)