An Engineer's Reference

Orders of Magnitude
of Time

From a single CPU clock tick to a decade of technological change. Eighteen orders of magnitude, made intuitive.

1 ns
10 years

The Logarithmic Ladder

Each row is 10× longer than the one above. Equal visual space, exponential real time.

Ratios That Build Intuition

The numbers are so vast they need analogies to land.

1,000×
RAM vs. cache
A main memory access (100ns) vs. L1 cache hit (0.5ns) is like waiting 3 minutes for coffee vs. 8 hours at the DMV.
100,000×
SSD vs. cache
An NVMe SSD read (~10μs) vs. an L1 cache hit (0.5ns). If the cache hit is one second, the SSD read is a full day.
10,000,000×
HDD seek vs. cache
A spinning disk seek (~5ms) vs. an L1 cache hit. If the cache is one second, the HDD seek is four months.
~1,000×
Cross-country vs. same-rack
A cross-country round trip (~40ms) vs. same-rack network hop (~40μs). Local is a thousand times faster.
31.5M
seconds in a year
π × 10⁷ is the classic engineering approximation. Close enough for napkin math, elegant enough to remember.
10¹⁷
ns in 10 years
The full span of this chart. A single nanosecond to a decade is 100 quadrillion to one. Your CPU does billions of operations before you finish reading this sentence.
Computing
  • L1 cache reference (~0.5–1ns)
  • Single CPU clock cycle at 1 GHz
  • Branch prediction hit — correct guess costs ~1 cycle
  • Register-to-register operation
  • Single instruction in a pipelined core
1ns
10⁻⁹ s
☀ Light: 30 cm (1 foot)
Physical World
  • Light travels 30 cm — about one foot, one ruler length
  • One microwave oscillation cycle (~0.4ns at 2.45 GHz)
  • Chemical bond vibration happens in this range
  • A photon crosses the width of a human hair ~300 times
  • Transistor switching in modern chips
Computing
  • L2 cache reference (~3–10ns)
  • Branch misprediction penalty (~5ns)
  • Mutex lock/unlock (~15–25ns uncontended)
  • SIMD vector operation on modern CPU
  • Virtual function call overhead
10ns
10⁻⁸ s
☀ Light: 3 m (across a room)
Physical World
  • Light crosses a room (~3 meters)
  • One WiFi radio cycle at 5 GHz (~0.2ns, many per 10ns)
  • Fastest electronic circuits switch at this scale
  • Acoustic wave in air moves ~3 micrometers
  • Fluorescence decay of many molecules
Computing
  • Main memory (DRAM) reference (~100ns) ← the big one
  • L3 cache miss penalty
  • System call overhead (~100–200ns)
  • NUMA remote memory access (~150ns)
  • Memory-mapped I/O register access
100ns
10⁻⁷ s
☀ Light: 30 m (a building's height)
Physical World
  • Light reaches the 10th floor of a building (~30m)
  • Sound travels ~0.03 mm — invisible distance
  • Single nerve impulse moves ~0.01mm
  • Piezoelectric crystal response time
  • Fast photodiode response for optical fiber
Computing
  • Compress 1 KB with Snappy (~3μs)
  • Context switch between threads (~1–5μs)
  • Send 2 KB over 1 Gbps network (~2μs)
  • Read 1 MB from L3 cache (~3μs)
  • Kernel-to-userspace transition overhead
  • RDMA network operation (~1–2μs)
1μs
10⁻⁶ s
☀ Light: 300 m (3 football fields)
Physical World
  • Camera flash strobe duration (~1μs for xenon)
  • Lightning return stroke channel illumination
  • Sound travels ~0.3 mm — a grain of sand
  • Housefly wing beat is ~4ms, so ~250μs per wing stroke phase
  • Single ultrasound pulse in medical imaging
  • A bullet moves about 1mm
Computing
  • NVMe SSD random read (~10–20μs)
  • Redis GET on localhost (~10–20μs)
  • Kernel network stack processing (~10μs)
  • Epoll event notification round trip
  • DPDK packet processing (~2–5μs)
  • gRPC call on loopback (~20–50μs)
10μs
10⁻⁵ s
☀ Light: 3 km (across a town)
Physical World
  • A bullet travels ~10 cm at this timescale
  • Sound moves ~3 mm
  • Fastest neuron spike (~10–20μs pulse width)
  • A raindrop falls ~0.1mm
  • Detonation front moves ~10cm in an explosive
Computing
  • SSD random write (~100μs)
  • Intra-datacenter round trip (~100–500μs)
  • HFT trade execution (~50–200μs for co-located)
  • Read 1 MB from SSD sequentially (~200μs)
  • Memcached GET over network (~100–200μs)
  • Garbage collection minor pause
100μs
10⁻⁴ s
☀ Light: 30 km
Physical World
  • Sound travels ~3 cm — width of a thumb
  • Fastest blink reflex initiation (~100μs muscle signal)
  • One period of a bass note (~100 Hz = 10ms, but 20kHz = 50μs)
  • A hummingbird heart beats every ~50ms (this is 1/500th of that)
  • Spark plug discharge duration
Computing
  • HDD seek begins (~2–10ms)
  • WiFi round trip (~1–5ms)
  • TCP packet, same cloud region (~1–3ms)
  • TLS handshake (1 round trip, same region)
  • One frame at 1000 fps = 1ms
  • Compress 1 MB with zstd (~1–3ms)
  • Same-AZ database query (simple)
1ms
10⁻³ s
☀ Light: 300 km (Seattle → Portland)
Physical World
  • Sound travels ~34 cm — about a foot
  • A hummingbird wing beat (~4ms full stroke)
  • The threshold of musical tempo perception
  • A camera shutter at 1/1000s exposure
  • A mosquito wing flaps once (~2ms)
  • A single audio sample at 44.1 kHz lasts ~23μs (43 per ms)
Computing
  • HDD seek (~5–10ms)
  • One frame at 60 fps = 16.7ms
  • One frame at 144 fps = 6.9ms
  • DNS lookup (cached resolver, ~5–20ms)
  • Same-region DB query (moderate)
  • GC major pause in Go/Java (~5–50ms)
  • Read 1 MB from HDD sequentially (~20ms)
10ms
10⁻² s
☀ Light: 3,000 km (NYC → Chicago)
Physical / Human
  • Audio delay threshold — humans detect ~10ms latency in audio
  • One heartbeat electrical impulse traverses the heart (~10ms)
  • Sound travels ~3.4 m — across a small room
  • A dog's ear twitch reaction
  • A single video frame at 30fps = 33ms
  • Visual flicker fusion — below ~15ms, you see continuous motion
Computing
  • Cross-country round trip (~30–70ms, e.g. Seattle → Virginia)
  • Transatlantic round trip (~100–150ms)
  • SSD sequential read 1 GB (~200ms)
  • UI lag threshold — users perceive delay >100ms
  • Google search response target (~200ms)
  • Serverless cold start (warm) (~50–200ms)
  • Full page render (well-optimized) (~100–300ms)
100ms
10⁻¹ s
☀ Light: 30,000 km (¾ around Earth)
Physical / Human
  • Blink of an eye — 150–300ms total
  • Fastest human reaction to visual stimulus (~150ms)
  • A spoken syllable — ~150–200ms
  • Sound travels ~34 m — across a concert hall
  • A tennis serve impact to return decision (~200ms)
  • Conscious awareness lag — brain takes ~100ms to "notice"
Computing
  • Serverless cold start (cold, heavy runtime) (~0.5–3s)
  • Full TLS handshake + TCP to distant server
  • Inter-continental API call with processing
  • npm install — single small package
  • Docker layer pull (small, cached)
  • GPT-4 first token latency (~0.5–2s)
  • PostgreSQL complex join on millions of rows
1s
10⁰ s
☀ Light: 300,000 km (to the Moon in 1.3s)
Physical / Human
  • One heartbeat at resting rate
  • One deep breath begins
  • One step while walking
  • Sound travels ~343 m — 3 football fields
  • A pendulum (1m length) swings once
  • Attention span checkpoint — "is this loading?"
Computing
  • Docker container boot (~5–15s)
  • Large API response with pagination
  • Moderate SQL query on big dataset (~5–30s)
  • npm install (cached, mid-size project)
  • webpack dev build (incremental)
  • AI image generation (Midjourney/SD) (~10–30s)
10s
10¹ s
☀ Light: 3M km (1% to Sun)
Physical / Human
  • Elevator ride — 3 floors
  • Pour a cup of coffee
  • A traffic light yellow phase (~3–5s)
  • Holding your breath starts to feel uncomfortable
  • Task-switching cost — getting back into flow
  • A bowling ball rolls from hand to pins
Computing
  • CI unit test suite (small-medium project)
  • Terraform plan on mid-size infrastructure
  • Docker image build (moderate, cached layers)
  • Claude/GPT generating a long, detailed response
  • Kubernetes pod startup (with image pull)
  • VM boot in cloud (~30–90s)
1min
60 s
☀ Light: 18M km (12% to Sun)
Physical / Human
  • Microwave a snack
  • Read a page of text (~250 words)
  • A commercial break on TV
  • Wash your hands (properly, 20s + drying)
  • Heart beats ~70 times
  • ISS travels ~460 km in orbit
Computing
  • Full CI/CD pipeline (build + test + deploy)
  • Large Docker build (no cache)
  • npm install from scratch (big monorepo)
  • Moderate ML model training (small dataset)
  • Database backup (medium-size)
  • Full webpack production build
10min
600 s
☀ Light: 180M km (past Sun)
Physical / Human
  • A coffee break
  • A standup meeting
  • A shower
  • Walk half a mile
  • A 5K runner at elite pace finishes
  • Blood circulates through your entire body once
Computing
  • Large codebase full rebuild (C++ monorepo)
  • Canary deployment to production
  • Large DB migration
  • Small ML model training (real dataset, GPU)
  • Full integration test suite (large project)
  • Security scan of a large codebase
1hr
3,600 s
☀ Light: 1.1B km (past Jupiter)
Physical / Human
  • A meeting
  • A commute (average US: ~27 min each way)
  • A TV episode (drama)
  • A workout
  • Earth rotates 15°
  • Your body produces ~200 billion red blood cells
Computing
  • Full regression test suite (massive project)
  • Medium ML model training (multi-GPU, real data)
  • Large-scale ETL batch pipeline
  • DNS propagation (worst case TTL)
  • Full index rebuild on TB-scale database
  • Let's Encrypt certificate issuance + propagation
1day
86,400 s
☀ Light: 26B km (past Neptune)
Physical / Human
  • A full work day — ~8 productive hours
  • A sleep cycle — 7-9 hours
  • Earth rotates once
  • Your heart beats ~100,000 times
  • You breathe ~20,000 times
  • ISS orbits Earth ~16 times
Computing
  • Sprint cycle (1-2 weeks)
  • Moderate feature development (design → ship)
  • Load testing campaign
  • Incident postmortem cycle (event → doc → action items)
  • Large ML model training (single GPU)
  • Code review cycle for complex PR
1wk
604,800 s
☀ Light: 181B km (past Voyager 1)
Physical / Human
  • A short vacation
  • Finish a book (casual reading pace)
  • Muscle recovery from intense training
  • A wound starts significant healing
  • Skin cells on your hand are replaced
  • Moon completes ¼ orbit
Computing
  • Ship a medium feature end-to-end
  • Security audit of a service
  • Performance optimization deep dive
  • Train a large ML model (multi-GPU cluster)
  • Cloud cost optimization cycle
  • Team onboarding to a new codebase
1mo
~2.6×10⁶ s
☀ Light: 780B km (0.08 light-yr)
Physical / Human
  • A billing cycle
  • Moon orbits Earth once (~29.5 days)
  • A habit starts forming (~21–30 days)
  • Red blood cells are about ⅓ through their lifecycle
  • Fingernails grow ~3mm
  • Noticeable fitness gains from new program
Computing
  • Major platform migration (monolith → microservices)
  • Build team competency in new technology
  • Full product lifecycle iteration (idea → launch → iterate)
  • API deprecation timeline
  • Large-scale infrastructure modernization phase
  • Training a frontier LLM (GPT-4 scale)
1yr
~3.15×10⁷ s
☀ Light: 1 light-year (9.46T km)
Physical / Human
  • Earth orbits the Sun
  • Seasons cycle once
  • A child goes from crawling to walking
  • Your body replaces most of its cells
  • Heart beats ~35 million times
  • You can meaningfully learn a new skill or language
Computing
  • Technology generation shift (mainframe→PC→mobile→cloud→AI)
  • Complete infrastructure modernization
  • Technical debt compounding — exponential cost growth
  • Programming language adoption curve (Go, Rust)
  • Moore's Law: ~6–7 doublings in transistor density
  • A startup's full journey (founding → IPO/acquisition)
10yr
~3.15×10⁸ s
☀ Light: 10 light-years (past nearest stars)
Physical / Human
  • A career chapter
  • A child grows from toddler to teenager
  • Cities visibly change — new buildings, new neighborhoods
  • Heart beats ~350 million times
  • Tectonic plates move ~25cm (a handspan)
  • Most of your close friendships will have turned over