Benchmarking redis gem vs hiredis vs custom Redis client

benchmark.rb

require 'bundler/inline'

require 'socket'
class MyRedis
  CRLF = "\r\n"

  def initialize
    @connection = TCPSocket.new('localhost', 6379)
    @connection.sync = false
  end

  def get(key)
    @connection << "*2\r\n$3\r\nget\r\n$#{key.bytesize}\r\n#{key}\r\n"
    @connection.flush
    result = @connection.gets
    if result.start_with?('$')
      value = ''
      bytesize = result.tap { |r| r[0] = '' }.to_i
      return nil if bytesize < 0 # Key does not exist
      @connection.read bytesize + 2, value
      value.chomp! CRLF
      value
    else
      raise "idk what to do with this: #{result.inspect}"
    end
  end
end

gemfile true do
  source 'https://rubygems.org'
  gem 'redis'
  gem 'hiredis'
  gem 'benchmark-ips'
end

require 'benchmark'
require 'benchmark/ips'
require 'redis'
require 'hiredis'

redis = Redis.new(driver: :ruby)
hiredis = Redis.new(driver: :hiredis)
myredis = MyRedis.new
key = "foo"
cpu_time_iterations = 100_000

# Quick functionality check on our custom Redis
redis.set key, "test"
if (myredis_value = myredis.get(key)) == (redis_value = redis.get(key))
  puts "Cache-hit function check passed"
else
  raise "Value mismatch. Redis: #{redis_value.inspect}, MyRedis: #{myredis_value.inspect}"
end
redis.del key
if myredis_value = myredis.get(key).nil?
  puts "Cache-miss function check passed"
else
  raise "MyRedis cache miss broken: #{myredis_value.inspect}"
end


puts
puts "Cache hit (returns a 2KB string)"
redis.set key, "." * 2048 # 2KB cache entry
Benchmark.ips do |x|
  x.report("ruby") { redis.get key }
  x.report("hiredis") { hiredis.get key }
  x.report("myredis") { myredis.get key  }

  x.compare!
end

puts
puts "Cache hit CPU time"
puts "ruby   : #{Benchmark.measure { cpu_time_iterations.times { redis.get key } }.total}"
puts "hiredis: #{Benchmark.measure { cpu_time_iterations.times { hiredis.get key } }.total}"
puts "myredis: #{Benchmark.measure { cpu_time_iterations.times { myredis.get key } }.total}"

puts
puts "Cache miss (returns nil)"
redis.del key
Benchmark.ips do |x|
  x.report("ruby") { redis.get key }
  x.report("hiredis") { hiredis.get key }
  x.report("myredis") { myredis.get key  }

  x.compare!
end

puts
puts "Cache miss CPU time"
puts "ruby   : #{Benchmark.measure { cpu_time_iterations.times { redis.get key } }.total}"
puts "hiredis: #{Benchmark.measure { cpu_time_iterations.times { hiredis.get key } }.total}"
puts "myredis: #{Benchmark.measure { cpu_time_iterations.times { myredis.get key } }.total}"

output-intel.txt

Fetching gem metadata from https://rubygems.org/....
Resolving dependencies...
Using benchmark-ips 2.8.4
Using bundler 2.2.3
Using hiredis 0.6.3
Using redis 4.2.5
Cache-hit function check passed
Cache-miss function check passed

Cache hit (returns a 2KB string)
Warming up --------------------------------------
                ruby     1.857k i/100ms
             hiredis     3.124k i/100ms
             myredis     3.184k i/100ms
Calculating -------------------------------------
                ruby     22.082k (±14.1%) i/s -    107.706k in   5.021179s
             hiredis     31.506k (± 1.7%) i/s -    159.324k in   5.058568s
             myredis     31.997k (± 2.8%) i/s -    162.384k in   5.079019s

Comparison:
             myredis:    31997.4 i/s
             hiredis:    31505.6 i/s - same-ish: difference falls within error
                ruby:    22081.8 i/s - 1.45x  (± 0.00) slower


Cache hit CPU time
ruby   : 3.7590459999999997
hiredis: 1.9650980000000011
myredis: 1.7395270000000007

Cache miss (returns nil)
Warming up --------------------------------------
                ruby     2.666k i/100ms
             hiredis     3.352k i/100ms
             myredis     3.440k i/100ms
Calculating -------------------------------------
                ruby     25.796k (± 8.2%) i/s -    127.968k in   5.006173s
             hiredis     33.267k (± 1.0%) i/s -    167.600k in   5.038516s
             myredis     34.693k (± 2.3%) i/s -    175.440k in   5.059694s

Comparison:
             myredis:    34693.1 i/s
             hiredis:    33267.0 i/s - 1.04x  (± 0.00) slower
                ruby:    25795.8 i/s - 1.34x  (± 0.00) slower


Cache miss CPU time
ruby   : 3.0532809999999984
hiredis: 1.840083
myredis: 1.5741099999999975

output-m1.txt

Fetching gem metadata from https://rubygems.org/....
Resolving dependencies...
Using bundler 2.2.15
Using hiredis 0.6.3
Using redis 4.2.5
Using benchmark-ips 2.8.4
Cache-hit function check passed
Cache-miss function check passed

Cache hit (returns a 2KB string)
Warming up --------------------------------------
                ruby     2.638k i/100ms
             hiredis     5.080k i/100ms
             myredis     5.741k i/100ms
Calculating -------------------------------------
                ruby     35.924k (±12.0%) i/s -    176.746k in   5.013467s
             hiredis     52.624k (± 4.7%) i/s -    264.160k in   5.034100s
             myredis     59.541k (± 1.1%) i/s -    298.532k in   5.014476s

Comparison:
             myredis:    59541.4 i/s
             hiredis:    52623.8 i/s - 1.13x  (± 0.00) slower
                ruby:    35924.1 i/s - 1.66x  (± 0.00) slower


Cache hit CPU time
ruby   : 1.751384999999999
hiredis: 0.9159620000000004
myredis: 0.6444190000000001

Cache miss (returns nil)
Warming up --------------------------------------
                ruby     4.234k i/100ms
             hiredis     5.594k i/100ms
             myredis     6.340k i/100ms
Calculating -------------------------------------
                ruby     42.602k (± 9.1%) i/s -    211.700k in   5.020637s
             hiredis     55.257k (± 4.7%) i/s -    279.700k in   5.074557s
             myredis     63.400k (± 1.6%) i/s -    317.000k in   5.001319s

Comparison:
             myredis:    63399.9 i/s
             hiredis:    55256.9 i/s - 1.15x  (± 0.00) slower
                ruby:    42601.6 i/s - 1.49x  (± 0.00) slower


Cache miss CPU time
ruby   : 1.417432999999999
hiredis: 0.832987000000001
myredis: 0.5722979999999982

Thanks for this script! It seems not compatible with Redis 5 though, so I ran with this change:

-   gem 'redis'
+   gem 'redis', '< 5'

Results on my macbook m3 pro, ruby 3.4.8:

Fetching gem metadata from https://rubygems.org/....
Resolving dependencies...
redis_clients_benchmark.rb:36: warning: benchmark was loaded from the standard library, but will no longer be part of the default gems starting from Ruby 4.0.0.
You can add benchmark to your Gemfile or gemspec to silence this warning.
Cache-hit function check passed
Cache-miss function check passed

Cache hit (returns a 2KB string)
ruby 3.4.8 (2025-12-17 revision 995b59f666) +PRISM [arm64-darwin24]
Warming up --------------------------------------
                ruby   270.000 i/100ms
             hiredis   296.000 i/100ms
             myredis   307.000 i/100ms
Calculating -------------------------------------
                ruby      2.991k (± 8.6%) i/s  (334.34 μs/i) -     14.850k in   5.003609s
             hiredis      3.543k (± 8.6%) i/s  (282.23 μs/i) -     17.760k in   5.045779s
             myredis      3.478k (± 6.0%) i/s  (287.54 μs/i) -     17.499k in   5.050804s

Comparison:
             hiredis:     3543.2 i/s
             myredis:     3477.8 i/s - same-ish: difference falls within error
                ruby:     2991.0 i/s - same-ish: difference falls within error


Cache hit CPU time
ruby   : 6.606366
hiredis: 4.617767
myredis: 3.2234870000000004

Cache miss (returns nil)
ruby 3.4.8 (2025-12-17 revision 995b59f666) +PRISM [arm64-darwin24]
Warming up --------------------------------------
                ruby   345.000 i/100ms
             hiredis   372.000 i/100ms
             myredis   386.000 i/100ms
Calculating -------------------------------------
                ruby      3.517k (±10.3%) i/s  (284.34 μs/i) -     17.595k in   5.051507s
             hiredis      3.609k (± 5.0%) i/s  (277.06 μs/i) -     18.228k in   5.061332s
             myredis      4.053k (±15.3%) i/s  (246.72 μs/i) -     20.072k in   5.043282s

Comparison:
             myredis:     4053.2 i/s
             hiredis:     3609.3 i/s - same-ish: difference falls within error
                ruby:     3517.0 i/s - same-ish: difference falls within error


Cache miss CPU time
ruby   : 7.849893000000002
hiredis: 5.808086000000001
myredis: 4.567702999999998