gen_dataset.rb

require 'rdf/turtle'
require 'json/ld'

g = RDF::Graph.load('http://json-ld.org/test-suite/reports/ruby-earl.ttl')
File.open('ruby-earl.json', 'w') { |file| file.write(g.dump(:jsonld, standard_prefixes: true)) }
File.open('ruby-earl.nt', 'w') { |file| file.write(g.dump(:ntriples)) }

json_ld.rb

# With Defoult JSON Parser

RUBY_VERSION # => "2.1.0"
require 'json/ld'
require 'benchmark'

puts Benchmark.bmbm { |bm| bm.report { JSON::LD::API.toRdf(File.open('ruby-earl.json')) } }
# Rehearsal ------------------------------------
#    0.480000   0.030000   0.510000 (  0.520427)
# --------------------------- total: 0.510000sec
# 
#        user     system      total        real
#    0.420000   0.000000   0.420000 (  0.425897)
#   0.420000   0.000000   0.420000 (  0.425897)

JSON::LD::API.toRdf(File.open('ruby-earl.json')).count # => 3642

json_ld_oj.rb

# With OJ

RUBY_VERSION # => "2.1.0"
require 'oj'
require 'json/ld'
require 'benchmark'

puts Benchmark.bmbm { |bm| bm.report { JSON::LD::API.toRdf(File.open('ruby-earl.json')) } }
# Rehearsal ------------------------------------
#    0.470000   0.020000   0.490000 (  0.490904)
# --------------------------- total: 0.490000sec
# 
#        user     system      total        real
#    0.410000   0.000000   0.410000 (  0.418465)
#   0.410000   0.000000   0.410000 (  0.418465)

JSON::LD::API.toRdf(File.open('ruby-earl.json')).count # => 3642

ntriples.rb

# For NTriples

require 'rdf/ntriples'
require 'benchmark'


Benchmark.bmbm { |bm| bm.report { RDF::Reader.open('ruby-earl.nt').count } }
# Rehearsal ------------------------------------
#    0.370000   0.010000   0.380000 (  0.374357)
# --------------------------- total: 0.380000sec
# 
#        user     system      total        real
#    0.370000   0.000000   0.370000 (  0.369633)