diff --git a/tools/run_tests/performance/scenario_config.py b/tools/run_tests/performance/scenario_config.py
index 8b239951498..8f76d0a02ea 100644
--- a/tools/run_tests/performance/scenario_config.py
+++ b/tools/run_tests/performance/scenario_config.py
@@ -29,7 +29,6 @@
 
 # performance scenario configuration for various languages
 
-SINGLE_MACHINE_CORES=8
 WARMUP_SECONDS=5
 JAVA_WARMUP_SECONDS=15  # Java needs more warmup time for JIT to kick in.
 BENCHMARK_SECONDS=30
@@ -197,7 +196,6 @@ class CXXLanguage:
       yield _ping_pong_scenario(
           'cpp_protobuf_async_unary_qps_unconstrained_%s' % secstr, rpc_type='UNARY',
           client_type='ASYNC_CLIENT', server_type='ASYNC_SERVER',
-          server_core_limit=SINGLE_MACHINE_CORES/2,
           use_unconstrained_client=True,
           secure=secure,
           categories=smoketest_categories)
@@ -205,7 +203,6 @@ class CXXLanguage:
       yield _ping_pong_scenario(
           'cpp_protobuf_async_streaming_qps_unconstrained_%s' % secstr, rpc_type='STREAMING',
           client_type='ASYNC_CLIENT', server_type='ASYNC_SERVER',
-          server_core_limit=SINGLE_MACHINE_CORES/2,
           use_unconstrained_client=True,
           secure=secure)
 
@@ -213,7 +210,6 @@ class CXXLanguage:
           'cpp_generic_async_streaming_qps_unconstrained_%s' % secstr, rpc_type='STREAMING',
           client_type='ASYNC_CLIENT', server_type='ASYNC_GENERIC_SERVER',
           use_unconstrained_client=True, use_generic_payload=True,
-          server_core_limit=SINGLE_MACHINE_CORES/2,
           secure=secure,
           categories=smoketest_categories)
 
diff --git a/tools/run_tests/tests.json b/tools/run_tests/tests.json
index 1939da7aec4..f1d302f2ef2 100644
--- a/tools/run_tests/tests.json
+++ b/tools/run_tests/tests.json
@@ -23105,7 +23105,7 @@
   {
     "args": [
       "--scenario_json", 
-      "'{\"name\": \"cpp_protobuf_async_unary_qps_unconstrained_secure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 4, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
+      "'{\"name\": \"cpp_protobuf_async_unary_qps_unconstrained_secure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -23131,7 +23131,7 @@
   {
     "args": [
       "--scenario_json", 
-      "'{\"name\": \"cpp_protobuf_async_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 4, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
+      "'{\"name\": \"cpp_protobuf_async_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -23157,7 +23157,7 @@
   {
     "args": [
       "--scenario_json", 
-      "'{\"name\": \"cpp_generic_async_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 4, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"server_type\": \"ASYNC_GENERIC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
+      "'{\"name\": \"cpp_generic_async_streaming_qps_unconstrained_secure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 0, \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"server_type\": \"ASYNC_GENERIC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": {\"use_test_ca\": true, \"server_host_override\": \"foo.test.google.fr\"}, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -23313,7 +23313,7 @@
   {
     "args": [
       "--scenario_json", 
-      "'{\"name\": \"cpp_protobuf_async_unary_qps_unconstrained_insecure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 4, \"security_params\": null, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
+      "'{\"name\": \"cpp_protobuf_async_unary_qps_unconstrained_insecure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 0, \"security_params\": null, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"UNARY\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -23339,7 +23339,7 @@
   {
     "args": [
       "--scenario_json", 
-      "'{\"name\": \"cpp_protobuf_async_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 4, \"security_params\": null, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
+      "'{\"name\": \"cpp_protobuf_async_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 0, \"security_params\": null, \"server_type\": \"ASYNC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": {\"simple_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
     ], 
     "boringssl": true, 
     "ci_platforms": [
@@ -23365,7 +23365,7 @@
   {
     "args": [
       "--scenario_json", 
-      "'{\"name\": \"cpp_generic_async_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 4, \"security_params\": null, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"server_type\": \"ASYNC_GENERIC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
+      "'{\"name\": \"cpp_generic_async_streaming_qps_unconstrained_insecure\", \"warmup_seconds\": 5, \"benchmark_seconds\": 30, \"num_servers\": 1, \"server_config\": {\"async_server_threads\": 0, \"core_limit\": 0, \"security_params\": null, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"server_type\": \"ASYNC_GENERIC_SERVER\"}, \"client_config\": {\"client_type\": \"ASYNC_CLIENT\", \"security_params\": null, \"payload_config\": {\"bytebuf_params\": {\"resp_size\": 0, \"req_size\": 0}}, \"client_channels\": 64, \"async_client_threads\": 0, \"outstanding_rpcs_per_channel\": 100, \"rpc_type\": \"STREAMING\", \"load_params\": {\"closed_loop\": {}}, \"histogram_params\": {\"max_possible\": 60000000000.0, \"resolution\": 0.01}}, \"num_clients\": 0}'"
     ], 
     "boringssl": true, 
     "ci_platforms": [