array_uniq_benchmark.rb

require "benchmark"
require "securerandom"

Benchmark.bm do |bm|
  15.times do |t|
    n = t * 10_000
    a = [].tap do |array|
      n.times { array << SecureRandom.uuid }
    end
    bm.report("#{n} uniq") { a.uniq }
  end
end

results.txt

       user     system      total        real
0 uniq  0.000000   0.000000   0.000000 (  0.000004)
10000 uniq  0.010000   0.000000   0.010000 (  0.005481)
20000 uniq  0.010000   0.000000   0.010000 (  0.013604)
30000 uniq  0.020000   0.000000   0.020000 (  0.022462)
40000 uniq  0.040000   0.000000   0.040000 (  0.035382)
50000 uniq  0.040000   0.000000   0.040000 (  0.045865)
60000 uniq  0.050000   0.000000   0.050000 (  0.048567)
70000 uniq  0.060000   0.000000   0.060000 (  0.059995)
80000 uniq  0.080000   0.000000   0.080000 (  0.078481)
90000 uniq  0.100000   0.000000   0.100000 (  0.107666)
100000 uniq  0.090000   0.000000   0.090000 (  0.094583)
110000 uniq  0.120000   0.000000   0.120000 (  0.129481)
120000 uniq  0.140000   0.010000   0.150000 (  0.143909)
130000 uniq  0.150000   0.010000   0.160000 (  0.153648)
140000 uniq  0.150000   0.000000   0.150000 (  0.145950)
ruby benchmark.rb  7.20s user 0.13s system 99% cpu 7.341 total