diff --git a/.github/workflows/pr-test.yml b/.github/workflows/pr-test.yml
index 76c0b96d5..f4e195a74 100644
--- a/.github/workflows/pr-test.yml
+++ b/.github/workflows/pr-test.yml
@@ -1614,53 +1614,54 @@ jobs:
           fi
           python3 run_suite.py --suite per-commit-4-gpu-deepep $RETRY_FLAG $CONTINUE_ON_ERROR_FLAG
 
-  unit-test-deepep-8-gpu:
-    needs: [check-changes, call-gate, stage-b-test-small-1-gpu, stage-b-test-large-1-gpu, stage-b-test-large-2-gpu, stage-b-test-4-gpu-b200]
-    if: |
-      always() &&
-      (
-        (inputs.target_stage == 'unit-test-deepep-8-gpu') ||
-        (
-          !inputs.target_stage &&
-          (github.event_name == 'schedule' || (!failure() && !cancelled())) &&
-          ((needs.check-changes.outputs.main_package == 'true') || (needs.check-changes.outputs.sgl_kernel == 'true'))
-        )
-      )
-    runs-on: 8-gpu-h200
-    env:
-      RUNNER_LABELS: 8-gpu-h200
-    steps:
-      - name: Checkout code
-        uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.pr_head_sha || inputs.ref || github.sha }}
-
-      - name: Download artifacts
-        if: needs.check-changes.outputs.sgl_kernel == 'true'
-        uses: actions/download-artifact@v4
-        with:
-          path: sgl-kernel/dist/
-          merge-multiple: true
-          pattern: wheel-python3.10-cuda12.9
-
-      - name: Install dependencies
-        timeout-minutes: 10
-        run: |
-          CUSTOM_BUILD_SGL_KERNEL=${{needs.check-changes.outputs.sgl_kernel}} bash scripts/ci/ci_install_deepep.sh
-
-      - name: Run test
-        timeout-minutes: 20
-        run: |
-          cd test/srt
-          RETRY_FLAG=""
-          if [[ "${{ needs.check-changes.outputs.enable_retry }}" == "true" ]]; then
-            RETRY_FLAG="--enable-retry"
-          fi
-          CONTINUE_ON_ERROR_FLAG=""
-          if [[ "${{ needs.check-changes.outputs.continue_on_error }}" == "true" ]]; then
-            CONTINUE_ON_ERROR_FLAG="--continue-on-error"
-          fi
-          python3 run_suite.py --suite per-commit-8-gpu-h200-deepep $RETRY_FLAG $CONTINUE_ON_ERROR_FLAG
+  # Disabled: IBGDA/cudaHostRegister environment issues on 8-GPU runner, see #17175
+  # unit-test-deepep-8-gpu:
+  #   needs: [check-changes, call-gate, stage-b-test-small-1-gpu, stage-b-test-large-1-gpu, stage-b-test-large-2-gpu, stage-b-test-4-gpu-b200]
+  #   if: |
+  #     always() &&
+  #     (
+  #       (inputs.target_stage == 'unit-test-deepep-8-gpu') ||
+  #       (
+  #         !inputs.target_stage &&
+  #         (github.event_name == 'schedule' || (!failure() && !cancelled())) &&
+  #         ((needs.check-changes.outputs.main_package == 'true') || (needs.check-changes.outputs.sgl_kernel == 'true'))
+  #       )
+  #     )
+  #   runs-on: 8-gpu-h200
+  #   env:
+  #     RUNNER_LABELS: 8-gpu-h200
+  #   steps:
+  #     - name: Checkout code
+  #       uses: actions/checkout@v4
+  #       with:
+  #         ref: ${{ inputs.pr_head_sha || inputs.ref || github.sha }}
+  #
+  #     - name: Download artifacts
+  #       if: needs.check-changes.outputs.sgl_kernel == 'true'
+  #       uses: actions/download-artifact@v4
+  #       with:
+  #         path: sgl-kernel/dist/
+  #         merge-multiple: true
+  #         pattern: wheel-python3.10-cuda12.9
+  #
+  #     - name: Install dependencies
+  #       timeout-minutes: 10
+  #       run: |
+  #         CUSTOM_BUILD_SGL_KERNEL=${{needs.check-changes.outputs.sgl_kernel}} bash scripts/ci/ci_install_deepep.sh
+  #
+  #     - name: Run test
+  #       timeout-minutes: 20
+  #       run: |
+  #         cd test/srt
+  #         RETRY_FLAG=""
+  #         if [[ "${{ needs.check-changes.outputs.enable_retry }}" == "true" ]]; then
+  #           RETRY_FLAG="--enable-retry"
+  #         fi
+  #         CONTINUE_ON_ERROR_FLAG=""
+  #         if [[ "${{ needs.check-changes.outputs.continue_on_error }}" == "true" ]]; then
+  #           CONTINUE_ON_ERROR_FLAG="--continue-on-error"
+  #         fi
+  #         python3 run_suite.py --suite per-commit-8-gpu-h200-deepep $RETRY_FLAG $CONTINUE_ON_ERROR_FLAG
 
   unit-test-backend-4-gpu-b200:
     needs: [check-changes, call-gate, stage-b-test-small-1-gpu, stage-b-test-large-1-gpu, stage-b-test-large-2-gpu, stage-b-test-4-gpu-b200]
@@ -1800,7 +1801,7 @@ jobs:
         accuracy-test-1-gpu,
         accuracy-test-2-gpu,
         unit-test-deepep-4-gpu,
-        unit-test-deepep-8-gpu,
+        # unit-test-deepep-8-gpu,  # Disabled, see #17175
         unit-test-backend-4-gpu-b200,
         unit-test-backend-4-gpu-gb200,
       ]
diff --git a/test/srt/run_suite.py b/test/srt/run_suite.py
index b00d0a297..fbc7c8154 100644
--- a/test/srt/run_suite.py
+++ b/test/srt/run_suite.py
@@ -48,9 +48,11 @@ suites = {
         TestFile("ep/test_deepep_small.py", 531),
         TestFile("ep/test_mooncake_ep_small.py", 660),
     ],
-    "per-commit-8-gpu-h200-deepep": [
-        TestFile("ep/test_deepep_large.py", 563),
-    ],
+    # Disabled: IBGDA/cudaHostRegister environment issues on 8-GPU runner, see #17175
+    # 4-GPU DeepEP tests provide sufficient coverage
+    # "per-commit-8-gpu-h200-deepep": [
+    #     TestFile("ep/test_deepep_large.py", 563),
+    # ],
     "quantization_test": [
         TestFile("quant/test_awq.py", 163),
         TestFile("quant/test_marlin_moe.py", 200),
@@ -74,6 +76,7 @@ suites = {
         TestFile(
             "models/test_qwen3_next_models_pcg.py"
         ),  # Disabled: intermittent failures, see #17039
+        TestFile("ep/test_deepep_large.py", 563),  # Disabled: see #17175
     ],
 }