diff --git a/.github/workflows/install-test-comment.yml b/.github/workflows/install-test-comment.yml
new file mode 100644
index 0000000..3820c3c
--- /dev/null
+++ b/.github/workflows/install-test-comment.yml
@@ -0,0 +1,118 @@
+name: Install test comment
+
+# Posts the install test's numbers on the pull request as one comment, kept
+# up to date on every run, next to quattro's latest numbers. GitHub runs
+# workflow_run workflows from the default branch, with write access even for
+# pull requests from forks, so this job never checks out or runs pull request
+# code: it only reads the finished run's artifact, as data.
+
+on:
+  workflow_run:
+    workflows: ["Install test"]
+    types: [completed]
+
+permissions:
+  actions: read
+  pull-requests: write
+
+jobs:
+  comment:
+    if: github.event.workflow_run.event == 'pull_request'
+    runs-on: ubuntu-latest
+    env:
+      GH_TOKEN: ${{ github.token }}
+      REPO: ${{ github.repository }}
+      RUN_ID: ${{ github.event.workflow_run.id }}
+      RUN_URL: ${{ github.event.workflow_run.html_url }}
+      HEAD_SHA: ${{ github.event.workflow_run.head_sha }}
+      CONCLUSION: ${{ github.event.workflow_run.conclusion }}
+    steps:
+      # A rerun keeps earlier attempts' artifacts under the same run, so take
+      # exactly the attempt that finished (and the baseline's latest attempt).
+      - name: Fetch this run's numbers and quattro's latest
+        env:
+          ATTEMPT: ${{ github.event.workflow_run.run_attempt }}
+        run: |
+          gh run download "$RUN_ID" -R "$REPO" -n "install-test-$RUN_ID-$ATTEMPT" -D pr || true
+          base=$(gh run list -R "$REPO" --workflow install-test.yml --branch quattro --event push \
+            --status success -L 1 --json databaseId -q '.[0].databaseId')
+          if [ -n "$base" ]; then
+            base_attempt=$(gh api "repos/$REPO/actions/runs/$base" -q .run_attempt)
+            gh run download "$base" -R "$REPO" -n "install-test-$base-$base_attempt" -D base || true
+          fi
+
+      - name: Comment on the pull request
+        run: |
+          set -euo pipefail
+          marker='<!-- omarchy-install-test -->'
+
+          # The number comes from the pull request's own run, so trust it only
+          # when that pull request's head is the commit this run tested.
+          pr=$({ find pr -name pr-number -exec cat {} + 2>/dev/null || true; } | head -1 | tr -dc 0-9)
+          [ -n "$pr" ] || { echo "No pull request number in the artifact"; exit 0; }
+          [ "$(gh api "repos/$REPO/pulls/$pr" -q .head.sha)" = "$HEAD_SHA" ] ||
+            { echo "PR #$pr has moved past $HEAD_SHA; not commenting"; exit 0; }
+
+          # Every lookup prints nothing rather than failing, so a missing baseline (none
+          # yet, or expired) shows as "–" instead of ending the script under set -e.
+          timing() { { find "$1" -name omarchy-install-timing.json 2>/dev/null || true; } | head -1; }
+          install_s() { [ -n "$1" ] || return 0; jq -r '.finished_at - .started_at' "$1" 2>/dev/null || true; }
+          # "Startup finished in … = 1min 2.3s" or "= 12.104s" -> seconds
+          boot_s() {
+            local f
+            f=$({ find "$1" -path "$2" 2>/dev/null || true; } | head -1)
+            [ -n "$f" ] || return 0
+            head -1 "$f" | sed -n 's/.*= *//p' |
+              awk '{t=0; for (i=1;i<=NF;i++) { if ($i ~ /min$/) t+=60*$i; else if ($i ~ /ms$/) t+=$i/1000; else t+=$i } printf "%.3f", t}'
+          }
+          cell() { [ -n "$1" ] && awk -v x="$1" 'BEGIN{printf "%.1f s", x}' || echo "–"; }
+          change() {
+            [ -n "$1" ] && [ -n "$2" ] || { echo "–"; return; }
+            awk -v a="$1" -v b="$2" 'BEGIN{d=a-b; printf "%s%.1f s", (d>=0?"+":"−"), (d<0?-d:d)}'
+          }
+
+          pt=$(timing pr); bt=$(timing base)
+          rows=(
+            "Install|$(install_s "$pt")|$(install_s "$bt")"
+            "First boot|$(boot_s pr '*/first-boot-systemd-analyze.txt')|$(boot_s base '*/first-boot-systemd-analyze.txt')"
+            "Everyday boot|$(boot_s pr '*-boot/systemd-analyze.txt')|$(boot_s base '*-boot/systemd-analyze.txt')"
+          )
+
+          status="passed"; [ "$CONCLUSION" = success ] || status="**${CONCLUSION}**"
+          {
+            echo "$marker"
+            echo "### Install test $status"
+            echo
+            echo "| | This PR | quattro | Change |"
+            echo "| --- | ---: | ---: | ---: |"
+            for row in "${rows[@]}"; do
+              IFS='|' read -r name this base_v <<<"$row"
+              echo "| $name | $(cell "$this") | $(cell "$base_v") | $(change "$this" "$base_v") |"
+            done
+            if [ -n "$pt" ]; then
+              echo
+              echo "<details><summary>Install phases</summary>"
+              echo
+              echo "| Phase | This PR | quattro |"
+              echo "| --- | ---: | ---: |"
+              # Phase names come from the pull request's installer: keep them to plain text.
+              jq -r --slurpfile b <( [ -n "$bt" ] && cat "$bt" || echo '{"phases":[]}' ) '
+                ($b[0].phases | map({key: .name, value: .elapsed}) | from_entries) as $base
+                | .phases[]
+                | "| \(.name | gsub("[^A-Za-z0-9 +&/().-]"; "") | .[0:60]) | \(.elapsed * 10 | round / 10) s | \(($base[.name] // null) | if . == null then "–" else "\(. * 10 | round / 10) s" end) |"
+              ' "$pt"
+              echo
+              echo "</details>"
+            fi
+            echo
+            echo "[Run]($RUN_URL) · ${HEAD_SHA:0:8}"
+          } > comment.md
+
+          existing=$(gh api "repos/$REPO/issues/$pr/comments" --paginate \
+            -q ".[] | select(.user.login == \"github-actions[bot]\" and (.body | startswith(\"$marker\"))) | .id" | head -1)
+          if [ -n "$existing" ]; then
+            gh api -X PATCH "repos/$REPO/issues/comments/$existing" -F body=@comment.md >/dev/null
+          else
+            gh api "repos/$REPO/issues/$pr/comments" -F body=@comment.md >/dev/null
+          fi
+          cat comment.md
diff --git a/.github/workflows/install-test.yml b/.github/workflows/install-test.yml
new file mode 100644
index 0000000..ccec9b0
--- /dev/null
+++ b/.github/workflows/install-test.yml
@@ -0,0 +1,117 @@
+name: Install test
+
+# Builds the ISO a pull request produces, installs it unattended in a KVM
+# guest, boots the installed system again, and reports how long the install
+# and both boots took. Every later change to the installer is measured
+# against these numbers in its own PR.
+
+on:
+  pull_request:
+  # Each merge records quattro's numbers, which PR comments compare against.
+  push:
+    branches: [quattro]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: install-test-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  install:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 75
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+
+      # The hosted runner has far more disk than the build needs (145 GB,
+      # ~86 GB free); fail early and loudly if that ever changes.
+      - name: Check disk space
+        run: |
+          df -h /
+          avail_gb=$(df -BG --output=avail / | tail -1 | tr -dc 0-9)
+          [ "$avail_gb" -ge 40 ] || { echo "::error::only ${avail_gb} GB free, the ISO build and install test need ~40 GB"; exit 1; }
+
+      - uses: docker/setup-buildx-action@37fe631027851001ddb9b187196cc803df7f5f0e # v4
+
+      - name: Build the ISO
+        run: NO_BOOT_OFFER=1 ./bin/omarchy-iso-make
+
+      # The harness runs in an Arch container: Arch's current QEMU and OVMF
+      # (QEMU 11) instead of Ubuntu 24.04's QEMU 8.2, at the paths the
+      # harness expects, the same as on an Omarchy workstation.
+      - name: Install unattended, then boot the installed system
+        run: |
+          sudo chmod 0666 /dev/kvm
+          docker run --rm --device /dev/kvm -v "$PWD:/w" -w /w \
+            -e OMARCHY_INTEGRATION_DISK_CACHE=none \
+            archlinux:latest bash -euo pipefail -c '
+              pacman -Syu --noconfirm --needed qemu-system-x86 qemu-hw-display-virtio-gpu qemu-hw-display-virtio-vga qemu-img edk2-ovmf socat \
+                imagemagick tesseract tesseract-data-eng mtools dosfstools jq openssh openssl python curl >/dev/null
+              # test/integration installs its tools through Omarchy'"'"'s helper; they are installed above.
+              printf "#!/bin/sh\nexit 0\n" >/usr/local/bin/omarchy-pkg-add
+              chmod 0755 /usr/local/bin/omarchy-pkg-add
+              qemu-system-x86_64 --version | head -1
+              ./test/integration release/*.iso boot --no-preview --memory 8192 --timeout 1800
+            '
+
+      # The harness ran as root in its container: test-runs and what QEMU
+      # wrote there (the serial logs) belong to root until this step.
+      - name: Hand the results to the runner's user
+        if: always()
+        run: |
+          mkdir -p test-runs
+          sudo chown -R "$(id -u):$(id -g)" test-runs
+
+      - name: Report times
+        if: always()
+        run: |
+          base=$(ls -d test-runs/*-integration 2>/dev/null | head -1)
+          [ -n "$base" ] || { echo "No test run to report" >> "$GITHUB_STEP_SUMMARY"; exit 0; }
+          {
+            echo "## Install test"
+            echo
+            if [ -f "$base/omarchy-install-timing.json" ]; then
+              jq -r '"**Install:** \((.finished_at - .started_at) * 10 | round / 10) s across \(.phases | length) phases"' "$base/omarchy-install-timing.json"
+              echo
+              echo "| Phase | Seconds |"
+              echo "| --- | ---: |"
+              jq -r '.phases[] | "| \(.name) | \(.elapsed * 10 | round / 10) |"' "$base/omarchy-install-timing.json"
+              echo
+            fi
+            if [ -f "$base/first-boot-systemd-analyze.txt" ]; then
+              echo "**First boot:** $(head -1 "$base/first-boot-systemd-analyze.txt")"
+              echo
+            fi
+            boot_dir=$(ls -d "$base"/runs/*-boot 2>/dev/null | tail -1)
+            if [ -n "$boot_dir" ] && [ -f "$boot_dir/systemd-analyze.txt" ]; then
+              echo "**Everyday boot:** $(head -1 "$boot_dir/systemd-analyze.txt")"
+              echo
+              echo "System state: $(jq -r .system_state "$boot_dir/boot-timing.json" 2>/dev/null)"
+            fi
+          } >> "$GITHUB_STEP_SUMMARY"
+
+      # The comment workflow runs from quattro and reads only this artifact;
+      # it needs the PR number, which a workflow_run event omits for forks.
+      - name: Record the pull request
+        if: always() && github.event_name == 'pull_request'
+        run: echo "${{ github.event.pull_request.number }}" > test-runs/pr-number
+
+      - name: Upload test artifacts
+        if: always()
+        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
+        with:
+          name: install-test-${{ github.run_id }}-${{ github.run_attempt }}
+          path: |
+            test-runs/pr-number
+            test-runs/*/omarchy-install-timing.json
+            test-runs/*/omarchy-install.log
+            test-runs/*/first-boot-systemd-analyze.txt
+            test-runs/*/runs/**/*.png
+            test-runs/*/runs/**/*.txt
+            test-runs/*/runs/**/*.json
+            test-runs/*/runs/**/*.log
+          if-no-files-found: ignore
+          retention-days: 14
diff --git a/test/integration.d/base-test.sh b/test/integration.d/base-test.sh
index df2d6ba..b9d4ab3 100644
--- a/test/integration.d/base-test.sh
+++ b/test/integration.d/base-test.sh
@@ -14,6 +14,9 @@ ISO="$OMARCHY_INTEGRATION_ISO"
 SSH_PORT="${OMARCHY_INTEGRATION_SSH_PORT:-2322}"
 MEMORY="${OMARCHY_INTEGRATION_MEMORY:-8192}"
 INSTALL_TIMEOUT="${OMARCHY_INTEGRATION_INSTALL_TIMEOUT:-2400}"
+# cache=none keeps the host page cache out of the guest's disk writes, so
+# install times measure the installer rather than the host (CI sets it).
+DISK_CACHE="${OMARCHY_INTEGRATION_DISK_CACHE:-}"
 NO_PREVIEW="${OMARCHY_INTEGRATION_NO_PREVIEW:-false}"
 BOOT_TIMEOUT=600
 
@@ -166,7 +169,7 @@ start_vm() {
     -m "$MEMORY" \
     -drive if=pflash,format=raw,readonly=on,file="$OVMF_CODE" \
     -drive if=pflash,format=raw,file="$ACTIVE_OVMF" \
-    -drive file="$disk",format=qcow2,if=none,id=drive0 \
+    -drive file="$disk",format=qcow2,if=none,id=drive0${DISK_CACHE:+,cache=$DISK_CACHE} \
     -device virtio-blk-pci,drive=drive0,bootindex=1 \
     -device virtio-vga \
     -display none \
@@ -282,8 +285,12 @@ ssh_sudo() {
   ssh_guest "echo $GUEST_PASSWORD | sudo -S -p '' bash -c $(printf %q "$1")"
 }
 
+# The deadline is wall-clock: under QEMU user networking every attempt can
+# spend its whole ConnectTimeout waiting for a banner, so counting only the
+# sleeps let a "300 s" wait run for ten minutes or more, silently.
 wait_for_ssh() {
-  local timeout="$1" failure_name="${2:-failure-ssh-timeout}" waited=0
+  local timeout="$1" failure_name="${2:-failure-ssh-timeout}"
+  local started=$SECONDS next_note=30 progress_name
 
   while ! ssh_guest true 2>/dev/null; do
     if ! vm_running; then
@@ -291,14 +298,20 @@ wait_for_ssh() {
       return 1
     fi
 
-    if ((waited >= timeout)); then
+    if ((SECONDS - started >= timeout)); then
       capture_console "$failure_name"
       echo "Timed out after ${timeout}s waiting for SSH" >&2
       return 1
     fi
 
-    sleep 5
-    ((waited += 5))
+    if ((SECONDS - started >= next_note)); then
+      printf -v progress_name 'waiting-ssh-%04ds' "$((SECONDS - started))"
+      capture_console "$progress_name"
+      echo "    ... waiting for SSH ($((SECONDS - started))s)"
+      ((next_note += 30))
+    fi
+
+    sleep 2
   done
 }
 
@@ -556,16 +569,28 @@ install_phase() {
       return 1
     fi
 
+    # A line every 30 s so a slow runner never looks hung; a screenshot of
+    # the installer's dashboard every 2 min, which is enough to see progress.
     if ((waited % 120 == 0)); then
       printf -v progress_name 'success-install-progress-%04ds' "$waited"
       capture_console "$progress_name"
-      echo "    ... installing (${waited}s)"
     fi
+    ((waited % 30 == 0)) && echo "    ... installing (${waited}s)"
 
     sleep 10
     ((waited += 10))
   done
 
+  # Keep the installer's own clock, its log and the first boot's numbers next
+  # to the base image while the system is reachable, so CI can report them
+  # without attaching the disk.
+  ssh_sudo "cat /var/log/omarchy-install-timing.json" >"$BASE_DIR/omarchy-install-timing.json" 2>/dev/null || true
+  ssh_sudo "cat /var/log/omarchy-install.log" >"$BASE_DIR/omarchy-install.log" 2>/dev/null || true
+  # SSH can answer before startup finishes, and systemd-analyze refuses until
+  # it has; wait (bounded) so the first-boot numbers are final.
+  ssh_guest "timeout 120 systemctl is-system-running --wait >/dev/null; systemd-analyze" \
+    >"$BASE_DIR/first-boot-systemd-analyze.txt" 2>/dev/null || true
+
   log "Installed system is up. Saving base image."
   stop_vm
   mv "$BASE_DISK.building" "$BASE_DISK"
diff --git a/test/integration.d/boot-test.sh b/test/integration.d/boot-test.sh
new file mode 100755
index 0000000..7bae941
--- /dev/null
+++ b/test/integration.d/boot-test.sh
@@ -0,0 +1,44 @@
+#!/bin/bash
+#
+# Everyday boot: boots the installed system a second time and records how
+# long it takes to answer SSH and what systemd-analyze reports, then asserts
+# that systemd finished starting with no failed units. CI reports these next
+# to the install time, so a change that slows booting shows up in its PR.
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+base_image_ready || { echo "No base image; run this through ./test/integration" >&2; exit 1; }
+
+log "Booting the installed system"
+boot_started=$(date +%s%N)
+start_vm_from_base
+if ! wait_for_ssh 300 failure-boot-ssh-timeout; then
+  # The console screenshot is saved; the serial log shows what the firmware,
+  # loader and kernel printed, which a screenshot of a hung boot often lacks.
+  echo "--- last lines of the serial console ---" >&2
+  tail -n 40 "$RUN_DIR/serial.log" >&2 2>/dev/null || true
+  exit 1
+fi
+boot_ms=$((($(date +%s%N) - boot_started) / 1000000))
+# Coarse: wait_for_ssh polls every 2 s. systemd-analyze below has the exact
+# firmware, loader, kernel and userspace split.
+log "SSH answered within ${boot_ms} ms of power-on"
+
+# --wait returns once startup has finished, so systemd-analyze has final
+# numbers and a unit that fails late in boot is still counted. It exits
+# non-zero for "degraded"; keep the answer so the diagnostics below are still
+# collected and the assertion reports it.
+state=$(ssh_guest "timeout 120 systemctl is-system-running --wait" 2>/dev/null | tr -d '\r' || true)
+ssh_guest "systemd-analyze" >"$RUN_DIR/systemd-analyze.txt" 2>/dev/null || true
+ssh_guest "systemd-analyze blame --no-pager | head -n 20" >"$RUN_DIR/systemd-analyze-blame.txt" 2>/dev/null || true
+# A query that fails must not read as "no failed units".
+ssh_guest "systemctl --failed --no-legend --plain" >"$RUN_DIR/failed-units.txt" 2>/dev/null ||
+  echo "could not query failed units over SSH" >"$RUN_DIR/failed-units.txt"
+printf '{"boot_to_ssh_ms": %d, "system_state": "%s"}\n' "$boot_ms" "$state" >"$RUN_DIR/boot-timing.json"
+
+check "systemd reports the system running (got: ${state:-nothing})" test "$state" = running
+check "no failed units" test ! -s "$RUN_DIR/failed-units.txt"
+capture_console "success-boot"
+
+stop_vm
+finish