diff --git a/.rubocop.yml b/.rubocop.yml
index d16abbe..bba2c39 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -24,3 +24,6 @@ Metrics/MethodLength:
 Metrics/AbcSize:
   Exclude:
     - "app/services/guide_card_loading_service.rb"
+
+Style/HashSyntax:
+  EnforcedShorthandSyntax: never
diff --git a/Gemfile b/Gemfile
index d450d59..d368327 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,6 +8,7 @@ ruby '3.2.0'
 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
 gem 'rails', '~> 7.0.4'
 
+gem 'async'
 gem 'bcrypt_pbkdf'
 gem 'ed25519'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index c2182d2..ff991f3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -71,6 +71,11 @@ GEM
     airbrussh (1.4.1)
       sshkit (>= 1.6.1, != 1.7.0)
     ast (2.4.2)
+    async (2.6.4)
+      console (~> 1.10)
+      fiber-annotation
+      io-event (~> 1.1)
+      timers (~> 4.1)
     bcrypt_pbkdf (1.1.0)
     bindex (0.8.1)
     bootsnap (1.16.0)
@@ -103,6 +108,9 @@ GEM
       xpath (~> 3.2)
     coderay (1.1.3)
     concurrent-ruby (1.2.2)
+    console (1.23.2)
+      fiber-annotation
+      fiber-local
     coveralls_reborn (0.27.0)
       simplecov (~> 0.22.0)
       term-ansicolor (~> 1.7)
@@ -118,6 +126,8 @@ GEM
     dry-cli (1.0.0)
     ed25519 (1.3.0)
     erubi (1.12.0)
+    fiber-annotation (0.2.0)
+    fiber-local (1.0.0)
     globalid (1.1.0)
       activesupport (>= 5.0)
     i18n (1.12.0)
@@ -126,6 +136,7 @@ GEM
       actionpack (>= 6.0.0)
       railties (>= 6.0.0)
     io-console (0.6.0)
+    io-event (1.3.2)
     irb (1.6.3)
       reline (>= 0.3.0)
     jbuilder (2.11.5)
@@ -295,6 +306,7 @@ GEM
       tins (~> 1.0)
     thor (1.2.1)
     timeout (0.3.2)
+    timers (4.3.5)
     tins (1.32.1)
       sync
     turbo-rails (1.4.0)
@@ -330,6 +342,7 @@ PLATFORMS
   x86_64-linux
 
 DEPENDENCIES
+  async
   bcrypt_pbkdf
   bootsnap
   capistrano (~> 3.10)
diff --git a/README.md b/README.md
index 2fc7455..9ec1e40 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@ To list all import services for the application: `rake -T | grep import`
 To import the GuideCard records (takes about 3 minutes): `rake import:import_guide_cards`
 To import the SubGuideCard records (takes about 2 minutes): `rake import:import_sub_guide_cards`
 
-The CardImage records are the images that are included in the GuideCard and SubGuideCard records. There are 5,786,727 images. These take about 12 days to import.
+The CardImage records are the images that are included in the GuideCard and SubGuideCard records. There are 5,786,727 images. These are estimated to take about 1 day to import.
 
 To import the CardImage records: `rake import:import_card_images`
 
diff --git a/app/services/card_image_loading_service.rb b/app/services/card_image_loading_service.rb
index 46a2988..d751acd 100644
--- a/app/services/card_image_loading_service.rb
+++ b/app/services/card_image_loading_service.rb
@@ -1,74 +1,80 @@
 # frozen_string_literal: true
 
 require 'ruby-progressbar'
+require 'ruby-progressbar/outputs/null'
+require 'async/semaphore'
+require 'async/barrier'
 
 # Class for card image loading service
 class CardImageLoadingService
-  attr_reader :progressbar
+  attr_reader :logger, :suppress_progress
 
-  def initialize(progressbar: nil)
-    @progressbar = progressbar || ProgressBar.create(format: "\e[1;35m%t: |%B|\e[0m")
+  def initialize(logger: nil, suppress_progress: false)
+    @logger = logger || Logger.new($stdout)
+    @suppress_progress = suppress_progress
   end
 
   def import
-    @progressbar = ProgressBar.create(format: "\e[1;35m%t: |%B|\e[0m")
-    import_guide_card_images
-    @progressbar = ProgressBar.create(format: "\e[1;35m%t: |%B|\e[0m")
-    import_sub_guide_images
-  end
-
-  # For each SubGuideCard, take its path and query s3 to get all of the image names
-  # for that path. For each image file, create a CardImage object with the path and
-  # image name.
+    barrier = Async::Barrier.new
+    Sync do
+      semaphore = Async::Semaphore.new(22, parent: barrier)
 
-  def import_sub_guide_images
-    @progressbar.total = SubGuideCard.all.count
-    SubGuideCard.all.each_with_index do |sgc, index|
-      progress_bar_random_color if (index % 100).zero?
-      @progressbar.increment
-      image_array(sgc.path).each do |file_name|
-        create_card_image(sgc, file_name)
-      end
+      (1..22).map do |disk|
+        semaphore.async do
+          import_disk(disk)
+        end
+      end.map(&:wait)
+    ensure
+      barrier.stop
     end
   end
 
-  def import_guide_card_images
-    @progressbar.total = GuideCard.all.count
-    GuideCard.all.each_with_index do |gc, index|
-      progress_bar_random_color if (index % 100).zero?
-      @progressbar.increment
-      image_array(gc.path).each do |file_name|
-        create_card_image(gc, file_name)
-      end
+  def import_disk(disk)
+    logger.info("Fetching disk #{disk} file list")
+    filenames = disk_array(disk)
+    progress_bar.total += filenames.count
+    Sync do
+      semaphore = Async::Semaphore.new(10_000)
+      filenames.map do |file_name|
+        semaphore.async do
+          progress_bar.increment
+          find_or_create_card_image(file_name)
+        end
+      end.map(&:wait)
     end
   end
 
+  private
+
   # returns something like
   # ["imagecat-disk9-0091-A3037-1358.0110.tif", "imagecat-disk9-0091-A3037-1358.0111.tif"]
-  def image_array(path)
-    s3_image_list(path).split("\n").map(&:split).map(&:last)
+  def disk_array(disk)
+    s3_disk_list(disk).split("\n").map(&:split).map(&:last)
   end
 
   # returns something like
   # "2023-07-19 14:39:38       3422 imagecat-disk9-0091-A3037-1358.0110.tif\n2023-07-19 14:39:38       7010 imagecat-disk9-0091-A3037-1358.0111.tif\n"
-  def s3_image_list(path)
-    s3_query = "aws s3 ls s3://puliiif-production/imagecat-disk#{path.tr('/', '-')}"
-    `#{s3_query}`
+  def s3_disk_list(disk)
+    `aws s3 ls s3://puliiif-production/imagecat-disk#{disk}-`
   end
 
-  private
-
-  def create_card_image(sgc, file_name)
-    ci = CardImage.find_by(path: sgc.path, image_name: file_name)
+  def find_or_create_card_image(file_name)
+    path = file_name.gsub('imagecat-disk', '').split('-')[0..-2].join('/')
+    ci = CardImage.find_by(path: path, image_name: file_name)
     return if ci
 
-    ci = CardImage.new
-    ci.path = sgc.path
-    ci.image_name = file_name
-    ci.save
+    CardImage.create(path: path, image_name: file_name)
+  end
+
+  def progress_bar
+    @progress_bar ||= ProgressBar.create(format: '%a %e %P% Loading: %c from %C', output: progress_output, total: 0, title: 'Image import')
+  end
+
+  def progress_bar_old(total)
+    ProgressBar.create(format: '%a %e %P% Loading: %c from %C', total: total, output: progress_output)
   end
 
-  def progress_bar_random_color
-    @progressbar.format = "%t: |\e[#{rand(91..97)}m%B\e[0m|"
+  def progress_output
+    ProgressBar::Outputs::Null if suppress_progress
   end
 end
diff --git a/spec/services/card_image_loading_service_spec.rb b/spec/services/card_image_loading_service_spec.rb
index c0aa10c..dbbba27 100644
--- a/spec/services/card_image_loading_service_spec.rb
+++ b/spec/services/card_image_loading_service_spec.rb
@@ -1,75 +1,62 @@
 # frozen_string_literal: true
 
 require 'rails_helper'
-require 'ruby-progressbar/outputs/null'
 
 describe CardImageLoadingService do
-  let(:cils) { described_class.new(progressbar: ProgressBar.create(output: ProgressBar::Outputs::Null)) }
-  let(:gcls) do
-    GuideCardLoadingService.new(csv_location: Rails.root.join('spec', 'fixtures', 'guide_card_fixture.csv'),
-                                progressbar: ProgressBar.create(output: ProgressBar::Outputs::Null))
+  let(:card_image_loader) do
+    described_class.new(
+      logger: Logger.new(nil),
+      suppress_progress: true
+    )
+  end
+  let(:guide_card_loader) do
+    GuideCardLoadingService.new(
+      csv_location: Rails.root.join('spec', 'fixtures', 'guide_card_fixture.csv'),
+      progressbar: ProgressBar.create(output: ProgressBar::Outputs::Null)
+    )
+  end
+  let(:sub_guide_card_loader) do
+    SubGuideLoadingService.new(
+      csv_location: Rails.root.join('spec', 'fixtures', 'subguide_card_fixture.csv'),
+      progressbar: ProgressBar.create(output: ProgressBar::Outputs::Null)
+    )
+  end
+
+  let(:s3_response_disk9) do
+    <<~HERE
+      2023-07-19 14:39:38       3422 imagecat-disk9-0091-A3037-1358.0110.tif
+      2023-07-19 14:39:38       7010 imagecat-disk9-0091-A3037-1358.0111.tif
+      2023-07-19 14:39:38       7010 imagecat-disk9-0091-A3038-0000.0001.tif
+      2023-07-19 14:39:38       7010 imagecat-disk9-0091-A3038-0000.0002.tif
+      2023-07-19 14:39:38       7010 imagecat-disk9-0091-A3038-0000.0003.tif
+      2023-07-19 14:39:38       7010 imagecat-disk9-0091-A3067-0000.0048.tif
+    HERE
+  end
+  let(:s3_response_disk14) do
+    <<~HERE
+      2023-07-19 14:39:38       3422 imagecat-disk14-0001-A1007-1358.0110.tif
+      2023-07-19 14:39:38       7010 imagecat-disk14-0001-A1007-1358.0111.tif
+      2023-07-19 14:39:38       7010 imagecat-disk14-0002-A1008-0000.0001.tif
+    HERE
   end
-  let(:sgls) do
-    SubGuideLoadingService.new(csv_location: Rails.root.join('spec', 'fixtures', 'subguide_card_fixture.csv'),
-                               progressbar: ProgressBar.create(output: ProgressBar::Outputs::Null))
-  end
-  let(:s3_response) do
-    "2023-07-19 14:39:38       3422 imagecat-disk9-0091-A3037-1358.0110.tif\n2023-07-19 14:39:38       7010 imagecat-disk9-0091-A3037-1358.0111.tif\n"
-  end
-
   before do
-    allow(cils).to receive(:s3_image_list).with(anything).and_return(s3_response)
-    # Any card with a path of "sub" will not have any images
-    allow(cils).to receive(:s3_image_list).with('sub').and_return('')
-  end
-
-  it 'can instantiate' do
-    expect(cils).to be_instance_of described_class
-  end
-
-  it 'imports all SubGuideCard images' do
-    sgls.import
-    expect(CardImage.count).to eq 0
-    cils.import_sub_guide_images
-    expect(CardImage.count).to eq 8
-    images = CardImage.where(path: '9/0091/A3037')
-    expect(images.map(&:image_name)).to contain_exactly('imagecat-disk9-0091-A3037-1358.0110.tif', 'imagecat-disk9-0091-A3037-1358.0111.tif')
-  end
-
-  it 'imports all GuideCard images' do
-    expect(GuideCard.count).to eq 0
-    gcls.import
-    expect(GuideCard.count).to eq 12
-    expect(CardImage.count).to eq 0
-    cils.import_guide_card_images
-    expect(CardImage.count).to eq 22
-    images = CardImage.where(path: '14/0001/A1003')
-    expect(images.map(&:image_name)).to contain_exactly('imagecat-disk9-0091-A3037-1358.0110.tif', 'imagecat-disk9-0091-A3037-1358.0111.tif')
-  end
-
-  it 'gets a list of images from s3' do
-    image_list = cils.s3_image_list('9/0091/A3037')
-    expect(image_list.split("\n").count).to eq 2
-  end
-
-  it 'displays ruby-progress bar during import' do
-    expect(cils.progressbar.to_h['percentage']).to eq 0
-    cils.import_sub_guide_images
-    expect(cils.progressbar.to_h['percentage']).to eq 100
-  end
-
-  it 'imports both GuideCard and SubGuideCard images' do
-    expect(GuideCard.count).to eq 0
-    expect(SubGuideCard.count).to eq 0
-    gcls.import
-    expect(GuideCard.count).to eq 12
-    sgls.import
-    expect(SubGuideCard.count).to eq 7
-    expect(CardImage.count).to eq 0
-    cils.import
-    expect(CardImage.count).to eq 30
+    allow(card_image_loader).to receive(:s3_disk_list).with(anything).and_return('')
+    allow(card_image_loader).to receive(:s3_disk_list).with(9).and_return(s3_response_disk9)
+    allow(card_image_loader).to receive(:s3_disk_list).with(14).and_return(s3_response_disk14)
+  end
+
+  it 'creates CardImage database entries based on the s3 listing' do
+    card_image_loader.import
+    expect(CardImage.find_by(image_name: 'imagecat-disk14-0002-A1008-0000.0001.tif').path).to eq '14/0002/A1008'
+    expect(CardImage.count).to eq 9
+    guide_card_loader.import
+    sub_guide_card_loader.import
+    gc = GuideCard.find_by(path: '14/0001/A1007')
+    expect(CardImage.where(path: gc.path).count).to eq 2
+    sgc = SubGuideCard.find_by(path: '9/0091/A3038')
+    expect(CardImage.where(path: sgc.path).count).to eq 3
     # If you reimport, it doesn't create duplicate rows
-    cils.import
-    expect(CardImage.count).to eq 30
+    card_image_loader.import
+    expect(CardImage.count).to eq 9
   end
 end