Memory and Storage Latency

Below you can see memory and storage latencies and their corresponding analogies. For example, a cache miss that triggers a memory access from RAM, is about 100 times slower than the L1 cache. A skilled engineer can make an app run at supersonic speed instead of at a snail's pace — often the difference between a popular app and a dead one.

Component	Latency	Order	Metaphorical Speed
CPU Register	~0.5 ns	1	🚀 3,600 km/h Supersonic jet
L1 Cache	~1 ns	1	✈️ 1,800 km/h Commercial jet
L2/L3 Cache	~ 5 ns	10	🚅 360 km/h High speed train
RAM (DRAM)	~100 ns	100	🛵 18 km/h Scooter
Flash (NOR)	~10 µs	10⁴	🐢 0.18 km/h Tortoise
NVMe SSD	~50 µs	10⁵	🐌 0.036 km/h Snail