diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 414cc81b748..dd262157eb9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -402,7 +402,7 @@ jobs:
       contents: read
     needs: [preflight]
     if: needs.preflight.outputs.run_build_artifacts == 'true'
-    runs-on: blacksmith-32vcpu-ubuntu-2404
+    runs-on: blacksmith-16vcpu-ubuntu-2404
     timeout-minutes: 20
     steps:
       - name: Checkout
@@ -499,7 +499,7 @@ jobs:
     name: ${{ matrix.check_name }}
     needs: [preflight]
     if: needs.preflight.outputs.run_checks_fast == 'true'
-    runs-on: blacksmith-32vcpu-ubuntu-2404
+    runs-on: blacksmith-16vcpu-ubuntu-2404
     timeout-minutes: 60
     strategy:
       fail-fast: false
@@ -869,7 +869,7 @@ jobs:
     name: ${{ matrix.check_name }}
     needs: [preflight, build-artifacts]
     if: always() && needs.preflight.outputs.run_checks == 'true' && needs.build-artifacts.result == 'success'
-    runs-on: blacksmith-32vcpu-ubuntu-2404
+    runs-on: blacksmith-16vcpu-ubuntu-2404
     timeout-minutes: 60
     strategy:
       fail-fast: false
@@ -931,7 +931,7 @@ jobs:
           install-bun: "false"
 
       - name: Configure Node test resources
-        run: echo "OPENCLAW_VITEST_MAX_WORKERS=4" >> "$GITHUB_ENV"
+        run: echo "OPENCLAW_VITEST_MAX_WORKERS=2" >> "$GITHUB_ENV"
 
       - name: Restore dist cache
         id: dist-cache
@@ -1165,7 +1165,7 @@ jobs:
     name: ${{ matrix.check_name }}
     needs: [preflight]
     if: always() && needs.preflight.outputs.run_check_additional == 'true'
-    runs-on: blacksmith-32vcpu-ubuntu-2404
+    runs-on: blacksmith-16vcpu-ubuntu-2404
     timeout-minutes: 20
     strategy:
       fail-fast: false
@@ -1235,7 +1235,7 @@ jobs:
         env:
           ADDITIONAL_CHECK_GROUP: ${{ matrix.group }}
           RUN_CONTROL_UI_I18N: ${{ needs.preflight.outputs.run_control_ui_i18n }}
-          OPENCLAW_EXTENSION_BOUNDARY_CONCURRENCY: 8
+          OPENCLAW_EXTENSION_BOUNDARY_CONCURRENCY: 4
         shell: bash
         run: |
           set -euo pipefail