diff --git a/.github/workflows/diffcalc.yml b/.github/workflows/diffcalc.yml
new file mode 100644
index 0000000000..842522ae87
--- /dev/null
+++ b/.github/workflows/diffcalc.yml
@@ -0,0 +1,199 @@
+# Listens for new PR comments containing !pp check [id], and runs a diffcalc comparison against master.
+# Usage:
+#   !pp check 0        | Runs only the osu! ruleset.
+#   !pp check 0 2      | Runs only the osu! and catch rulesets.
+#
+
+name: Difficulty Calculation
+on:
+  issue_comment:
+    types: [ created ]
+
+env:
+  CONCURRENCY: 4
+  ALLOW_DOWNLOAD: 1
+  SAVE_DOWNLOADED: 1
+  SKIP_INSERT_ATTRIBUTES: 1
+
+jobs:
+  metadata:
+    name: Check for requests
+    runs-on: self-hosted
+    if: github.event.issue.pull_request && contains(github.event.comment.body, '!pp check') && (github.event.comment.author_association == 'MEMBER' || github.event.comment.author_association == 'OWNER')
+    outputs:
+      matrix: ${{ steps.generate-matrix.outputs.matrix }}
+      continue: ${{ steps.generate-matrix.outputs.continue }}
+    steps:
+      - name: Construct build matrix
+        id: generate-matrix
+        run: |
+          if [[ "${{ github.event.comment.body }}" =~ "osu" ]] ; then
+            MATRIX_PROJECTS_JSON+='{ "name": "osu", "id": 0 },'
+          fi
+          if [[ "${{ github.event.comment.body }}" =~ "taiko" ]] ; then
+            MATRIX_PROJECTS_JSON+='{ "name": "taiko", "id": 1 },'
+          fi
+          if [[ "${{ github.event.comment.body }}" =~ "catch" ]] ; then
+            MATRIX_PROJECTS_JSON+='{ "name": "catch", "id": 2 },'
+          fi
+          if [[ "${{ github.event.comment.body }}" =~ "mania" ]] ; then
+            MATRIX_PROJECTS_JSON+='{ "name": "mania", "id": 3 },'
+          fi
+
+          if [[ "${MATRIX_PROJECTS_JSON}" != "" ]]; then
+            MATRIX_JSON="{ \"ruleset\": [ ${MATRIX_PROJECTS_JSON} ] }"
+            echo "${MATRIX_JSON}"
+            CONTINUE="yes"
+          else
+            CONTINUE="no"
+          fi
+
+          echo "::set-output name=continue::${CONTINUE}"
+          echo "::set-output name=matrix::${MATRIX_JSON}"
+  diffcalc:
+    name: Run
+    runs-on: self-hosted
+    if: needs.metadata.outputs.continue == 'yes'
+    needs: metadata
+    strategy:
+      matrix: ${{ fromJson(needs.metadata.outputs.matrix) }}
+    steps:
+      - name: Verify MySQL connection from host
+        run: |
+          mysql -e "SHOW DATABASES"
+
+      - name: Drop previous databases
+        run: |
+          for db in osu_master osu_pr
+          do
+            mysql -e "DROP DATABASE IF EXISTS $db"
+          done
+
+      - name: Create directory structure
+        run: |
+          mkdir -p $GITHUB_WORKSPACE/master/
+          mkdir -p $GITHUB_WORKSPACE/pr/
+
+      # Checkout osu
+      - name: Checkout osu (master)
+        uses: actions/checkout@v2
+        with:
+          repository: peppy/osu
+          ref: 'diffcalc-optimisations'
+          path: 'master/osu'
+      - name: Checkout osu (pr)
+        uses: actions/checkout@v2
+        with:
+          path: 'pr/osu'
+
+      - name: Checkout osu-difficulty-calculator (master)
+        uses: actions/checkout@v2
+        with:
+          repository: peppy/osu-difficulty-calculator
+          ref: 'bypass-attrib-row-insert'
+          path: 'master/osu-difficulty-calculator'
+      - name: Checkout osu-difficulty-calculator (pr)
+        uses: actions/checkout@v2
+        with:
+          repository: peppy/osu-difficulty-calculator
+          ref: 'bypass-attrib-row-insert'
+          path: 'pr/osu-difficulty-calculator'
+
+      - name: Install .NET 5.0.x
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: "5.0.x"
+
+      # Sanity checks to make sure diffcalc is not run when incompatible.
+      - name: Build diffcalc (master)
+        run: |
+          cd $GITHUB_WORKSPACE/master/osu-difficulty-calculator
+          ./UseLocalOsu.sh
+          dotnet build
+      - name: Build diffcalc (pr)
+        run: |
+          cd $GITHUB_WORKSPACE/pr/osu-difficulty-calculator
+          ./UseLocalOsu.sh
+          dotnet build
+
+      - name: Download + import data
+        run: |
+          PERFORMANCE_DATA_NAME=$(curl https://data.ppy.sh/ | grep performance_${{ matrix.ruleset.name }}_top_1000 | tail -1 | awk -F "\"" '{print $2}' | sed 's/\.tar\.bz2//g')
+          BEATMAPS_DATA_NAME=$(curl https://data.ppy.sh/ | grep osu_files | tail -1 | awk -F "\"" '{print $2}' | sed 's/\.tar\.bz2//g')
+
+          # Set env variable for further steps.
+          echo "BEATMAPS_PATH=$GITHUB_WORKSPACE/$BEATMAPS_DATA_NAME" >> $GITHUB_ENV
+
+          cd $GITHUB_WORKSPACE
+
+          echo "Downloading database dump $PERFORMANCE_DATA_NAME.."
+          wget -q -nc https://data.ppy.sh/$PERFORMANCE_DATA_NAME.tar.bz2
+          echo "Extracting.."
+          tar -xf $PERFORMANCE_DATA_NAME.tar.bz2
+
+          echo "Downloading beatmap dump $BEATMAPS_DATA_NAME.."
+          wget -q -nc https://data.ppy.sh/$BEATMAPS_DATA_NAME.tar.bz2
+          echo "Extracting.."
+          tar -xf $BEATMAPS_DATA_NAME.tar.bz2
+
+          cd $PERFORMANCE_DATA_NAME
+
+          for db in osu_master osu_pr
+          do
+            echo "Setting up database $db.."
+
+            mysql -e "CREATE DATABASE $db"
+
+            echo "Importing beatmaps.."
+            cat osu_beatmaps.sql | mysql $db
+            echo "Importing beatmapsets.."
+            cat osu_beatmapsets.sql | mysql $db
+
+            echo "Creating table structure.."
+            mysql $db -e 'CREATE TABLE `osu_beatmap_difficulty` (
+                `beatmap_id` int unsigned NOT NULL,
+                `mode` tinyint NOT NULL DEFAULT 0,
+                `mods` int unsigned NOT NULL,
+                `diff_unified` float NOT NULL,
+                `last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+                PRIMARY KEY (`beatmap_id`,`mode`,`mods`),
+                KEY `diff_sort` (`mode`,`mods`,`diff_unified`)
+              ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;'
+          done
+
+      - name: Run diffcalc (master)
+        env:
+          DB_NAME: osu_master
+        run: |
+          cd $GITHUB_WORKSPACE/master/osu-difficulty-calculator/osu.Server.DifficultyCalculator
+          dotnet run -c:Release -- all -m ${{ matrix.ruleset.id }} -ac -c ${{ env.CONCURRENCY }}
+      - name: Run diffcalc (pr)
+        env:
+          DB_NAME: osu_pr
+        run: |
+          cd $GITHUB_WORKSPACE/pr/osu-difficulty-calculator/osu.Server.DifficultyCalculator
+          dotnet run -c:Release -- all -m ${{ matrix.ruleset.id }} -ac -c ${{ env.CONCURRENCY }}
+
+      - name: Print diffs
+        run: |
+          mysql -e "
+            SELECT
+              m.beatmap_id,
+              m.mods,
+              b.filename,
+              m.diff_unified as 'sr_master',
+              p.diff_unified as 'sr_pr',
+              (p.diff_unified - m.diff_unified) as 'diff'
+            FROM osu_master.osu_beatmap_difficulty m
+            JOIN osu_pr.osu_beatmap_difficulty p
+              ON m.beatmap_id = p.beatmap_id
+              AND m.mode = p.mode
+              AND m.mods = p.mods
+            JOIN osu_pr.osu_beatmaps b
+              ON b.beatmap_id = p.beatmap_id
+            WHERE abs(m.diff_unified - p.diff_unified) > 0.1
+            ORDER BY abs(m.diff_unified - p.diff_unified)
+              DESC
+            LIMIT 10000;"
+
+      # Todo: Run ppcalc
diff --git a/.github/workflows/test-diffcalc.yml b/.github/workflows/test-diffcalc.yml
deleted file mode 100644
index 4274d01bab..0000000000
--- a/.github/workflows/test-diffcalc.yml
+++ /dev/null
@@ -1,163 +0,0 @@
-# Listens for new PR comments containing !pp check [id], and runs a diffcalc comparison against master.
-# Usage:
-#   !pp check 0        | Runs only the osu! ruleset.
-#   !pp check 0 2      | Runs only the osu! and catch rulesets.
-#
-
-name: Diffcalc Consistency Checks
-on:
-  issue_comment:
-    types: [ created ]
-
-env:
-  DB_USER: root
-  DB_HOST: 127.0.0.1
-  CONCURRENCY: 4
-  ALLOW_DOWNLOAD: 1
-  SAVE_DOWNLOADED: 1
-
-jobs:
-  diffcalc:
-    name: Diffcalc
-    runs-on: ubuntu-latest
-    continue-on-error: true
-
-    if: |
-      github.event.issue.pull_request &&
-      contains(github.event.comment.body, '!pp check') &&
-      (github.event.comment.author_association == 'MEMBER' || github.event.comment.author_association == 'OWNER')
-
-    strategy:
-      fail-fast: false
-      matrix:
-        ruleset:
-          - { name: osu, id: 0 }
-          - { name: taiko, id: 1 }
-          - { name: catch, id: 2 }
-          - { name: mania, id: 3 }
-
-    services:
-      mysql:
-        image: mysql:8.0
-        env:
-          MYSQL_ALLOW_EMPTY_PASSWORD: yes
-        ports:
-          - 3306:3306
-        options: --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=3
-
-    steps:
-      - name: Verify ruleset
-        if: contains(github.event.comment.body, matrix.ruleset.id) == false
-        run: |
-          echo "${{ github.event.comment.body }} doesn't contain ${{ matrix.ruleset.id }}"
-          exit 1
-
-      - name: Verify MySQL connection from host
-        run: |
-          sudo apt-get install -y mysql-client
-          mysql --host ${{ env.DB_HOST }} -u${{ env.DB_USER }} -e "SHOW DATABASES"
-
-      - name: Create directory structure
-        run: |
-          mkdir -p $GITHUB_WORKSPACE/master/
-          mkdir -p $GITHUB_WORKSPACE/pr/
-
-      # Checkout osu
-      - name: Checkout osu (master)
-        uses: actions/checkout@v2
-        with:
-          repository: ppy/osu
-          path: 'master/osu'
-      - name: Checkout osu (pr)
-        uses: actions/checkout@v2
-        with:
-          path: 'pr/osu'
-
-      # Checkout osu-difficulty-calculator
-      - name: Checkout osu-difficulty-calculator (master)
-        uses: actions/checkout@v2
-        with:
-          repository: ppy/osu-difficulty-calculator
-          path: 'master/osu-difficulty-calculator'
-      - name: Checkout osu-difficulty-calculator (pr)
-        uses: actions/checkout@v2
-        with:
-          repository: ppy/osu-difficulty-calculator
-          path: 'pr/osu-difficulty-calculator'
-
-      - name: Install .NET 5.0.x
-        uses: actions/setup-dotnet@v1
-        with:
-          dotnet-version: "5.0.x"
-
-      # Sanity checks to make sure diffcalc is not run when incompatible.
-      - name: Build diffcalc (master)
-        run: |
-          cd $GITHUB_WORKSPACE/master/osu-difficulty-calculator
-          ./UseLocalOsu.sh
-          dotnet build
-      - name: Build diffcalc (pr)
-        run: |
-          cd $GITHUB_WORKSPACE/pr/osu-difficulty-calculator
-          ./UseLocalOsu.sh
-          dotnet build
-
-      # Initial data imports
-      - name: Download + import data
-        run: |
-          PERFORMANCE_DATA_NAME=$(curl https://data.ppy.sh/ | grep performance_${{ matrix.ruleset.name }}_top | tail -1 | awk -F "\"" '{print $2}' | sed 's/\.tar\.bz2//g')
-          BEATMAPS_DATA_NAME=$(curl https://data.ppy.sh/ | grep osu_files | tail -1 | awk -F "\"" '{print $2}' | sed 's/\.tar\.bz2//g')
-
-          # Set env variable for further steps.
-          echo "BEATMAPS_PATH=$GITHUB_WORKSPACE/$BEATMAPS_DATA_NAME" >> $GITHUB_ENV
-
-          cd $GITHUB_WORKSPACE
-
-          wget https://data.ppy.sh/$PERFORMANCE_DATA_NAME.tar.bz2
-          wget https://data.ppy.sh/$BEATMAPS_DATA_NAME.tar.bz2
-          tar -xf $PERFORMANCE_DATA_NAME.tar.bz2
-          tar -xf $BEATMAPS_DATA_NAME.tar.bz2
-
-          cd $GITHUB_WORKSPACE/$PERFORMANCE_DATA_NAME
-
-          mysql --host ${{ env.DB_HOST }} -u${{ env.DB_USER }} -e "CREATE DATABASE osu_master"
-          mysql --host ${{ env.DB_HOST }} -u${{ env.DB_USER }} -e "CREATE DATABASE osu_pr"
-
-          cat *.sql | mysql --host ${{ env.DB_HOST }} -u${{ env.DB_USER }} --database=osu_master
-          cat *.sql | mysql --host ${{ env.DB_HOST }} -u${{ env.DB_USER }} --database=osu_pr
-
-      # Run diffcalc
-      - name: Run diffcalc (master)
-        env:
-          DB_NAME: osu_master
-        run: |
-          cd $GITHUB_WORKSPACE/master/osu-difficulty-calculator/osu.Server.DifficultyCalculator
-          dotnet run -c:Release -- all -m ${{ matrix.ruleset.id }} -ac -c ${{ env.CONCURRENCY }}
-      - name: Run diffcalc (pr)
-        env:
-          DB_NAME: osu_pr
-        run: |
-          cd $GITHUB_WORKSPACE/pr/osu-difficulty-calculator/osu.Server.DifficultyCalculator
-          dotnet run -c:Release -- all -m ${{ matrix.ruleset.id }} -ac -c ${{ env.CONCURRENCY }}
-
-      # Print diffs
-      - name: Print diffs
-        run: |
-          mysql --host ${{ env.DB_HOST }} -u${{ env.DB_USER }} -e "
-            SELECT
-              m.beatmap_id,
-              m.mods,
-              m.diff_unified as 'sr_master',
-              p.diff_unified as 'sr_pr',
-              (p.diff_unified - m.diff_unified) as 'diff'
-            FROM osu_master.osu_beatmap_difficulty m
-            JOIN osu_pr.osu_beatmap_difficulty p
-              ON m.beatmap_id = p.beatmap_id
-              AND m.mode = p.mode
-              AND m.mods = p.mods
-            WHERE abs(m.diff_unified - p.diff_unified) > 0.1
-            ORDER BY abs(m.diff_unified - p.diff_unified)
-              DESC
-            LIMIT 10000;"
-
-      # Todo: Run ppcalc
\ No newline at end of file