5hun Yanaura yanana

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs



	# ==== Emojis ====
	# 🎨 :art: improving format/structure of the code
	# 🔧 :wrench: infra/tooling
	# 🔎 :mag: when adding or improving the code for monitoring
	# 🐛 :bug: when fixing bug
	# 👍 :+1: improved feature
	# ✨ :sparkles: when adding a partial feature
	# 🎉 :tada: big feature

	import org.scalatest.prop.GeneratorDrivenPropertyChecks
	import org.scalatest.{ Matchers, WordSpec }

	class SomeSpec extends WordSpec with Matchers with GeneratorDrivenPropertyChecks {
	"this test should fail without sbt exceptions" in {
	forAll { value: Int =>
	assert(value !== value)
	// value shouldNot equal(value)
	}
	}