diff --git a/bench/bench-encryption.sh b/bench/bench-encryption.sh
index 1b239f7d..daea9c41 100755
--- a/bench/bench-encryption.sh
+++ b/bench/bench-encryption.sh
@@ -109,12 +109,12 @@ KEY_FILE=$(mktemp)
 dd if=/dev/urandom bs=32 count=1 2>/dev/null > "$KEY_FILE"
 
 echo "starting plaintext server on port $PLAINTEXT_PORT..."
-$EMBER_BIN --port "$PLAINTEXT_PORT" --data-dir "$TMPDIR_PLAIN" --appendonly > /dev/null 2>&1 &
+$EMBER_BIN --port "$PLAINTEXT_PORT" --data-dir "$TMPDIR_PLAIN" --appendonly --no-grpc > /dev/null 2>&1 &
 PLAINTEXT_PID=$!
 wait_for_server "$PLAINTEXT_PORT" "ember (plaintext)"
 
 echo "starting encrypted server on port $ENCRYPTED_PORT..."
-$EMBER_BIN --port "$ENCRYPTED_PORT" --data-dir "$TMPDIR_ENC" --appendonly --encryption-key-file "$KEY_FILE" > /dev/null 2>&1 &
+$EMBER_BIN --port "$ENCRYPTED_PORT" --data-dir "$TMPDIR_ENC" --appendonly --encryption-key-file "$KEY_FILE" --no-grpc > /dev/null 2>&1 &
 ENCRYPTED_PID=$!
 wait_for_server "$ENCRYPTED_PORT" "ember (encrypted)"
 
diff --git a/bench/bench-memory.sh b/bench/bench-memory.sh
index a4c85495..c1292d38 100755
--- a/bench/bench-memory.sh
+++ b/bench/bench-memory.sh
@@ -185,7 +185,7 @@ TYPE_LABELS+=("string (${VALUE_SIZE}B)")
 
 # ember concurrent
 echo "  starting ember concurrent..."
-$EMBER_BIN --port $EMBER_CONCURRENT_PORT --concurrent > /dev/null 2>&1 &
+$EMBER_BIN --port $EMBER_CONCURRENT_PORT --concurrent --no-grpc > /dev/null 2>&1 &
 EC_PID=$!
 wait_for_server $EMBER_CONCURRENT_PORT
 
@@ -198,7 +198,7 @@ sleep 0.5
 
 # ember sharded
 echo "  starting ember sharded..."
-$EMBER_BIN --port $EMBER_SHARDED_PORT > /dev/null 2>&1 &
+$EMBER_BIN --port $EMBER_SHARDED_PORT --no-grpc > /dev/null 2>&1 &
 ES_PID=$!
 wait_for_server $EMBER_SHARDED_PORT
 
@@ -236,7 +236,7 @@ TYPE_LABELS+=("hash (5 fields)")
 EMBER_CONCURRENT_BYTES+=("—")
 
 echo "  starting ember sharded..."
-$EMBER_BIN --port $EMBER_SHARDED_PORT > /dev/null 2>&1 &
+$EMBER_BIN --port $EMBER_SHARDED_PORT --no-grpc > /dev/null 2>&1 &
 ES_PID=$!
 wait_for_server $EMBER_SHARDED_PORT
 
@@ -272,7 +272,7 @@ TYPE_LABELS+=("sorted set")
 EMBER_CONCURRENT_BYTES+=("—")
 
 echo "  starting ember sharded..."
-$EMBER_BIN --port $EMBER_SHARDED_PORT > /dev/null 2>&1 &
+$EMBER_BIN --port $EMBER_SHARDED_PORT --no-grpc > /dev/null 2>&1 &
 ES_PID=$!
 wait_for_server $EMBER_SHARDED_PORT
 
@@ -342,7 +342,7 @@ PYEOF
 
         # vector requires sharded mode
         echo "  starting ember sharded..."
-        $EMBER_BIN --port $EMBER_SHARDED_PORT > /dev/null 2>&1 &
+        $EMBER_BIN --port $EMBER_SHARDED_PORT --no-grpc > /dev/null 2>&1 &
         VEC_PID=$!
         wait_for_server $EMBER_SHARDED_PORT
 
diff --git a/bench/bench-memtier.sh b/bench/bench-memtier.sh
index df40c34c..7d34ae32 100755
--- a/bench/bench-memtier.sh
+++ b/bench/bench-memtier.sh
@@ -324,13 +324,13 @@ declare -a D_P99=()
 
 # ember concurrent
 start_server "ember concurrent" "$EMBER_CONCURRENT_PORT" \
-    "$EMBER_BIN" --port "$EMBER_CONCURRENT_PORT" --concurrent
+    "$EMBER_BIN" --port "$EMBER_CONCURRENT_PORT" --concurrent --no-grpc
 run_server_tests "$EMBER_CONCURRENT_PORT" "ember concurrent" EC_OPS EC_P99
 stop_server
 
 # ember sharded
 start_server "ember sharded" "$EMBER_SHARDED_PORT" \
-    "$EMBER_BIN" --port "$EMBER_SHARDED_PORT"
+    "$EMBER_BIN" --port "$EMBER_SHARDED_PORT" --no-grpc
 run_server_tests "$EMBER_SHARDED_PORT" "ember sharded" ES_OPS ES_P99
 stop_server
 
diff --git a/bench/bench.sh b/bench/bench.sh
index 4abd5234..e51bb25b 100755
--- a/bench/bench.sh
+++ b/bench/bench.sh
@@ -57,8 +57,8 @@ fi
 cleanup
 
 echo "starting servers..."
-$EMBER_BIN --port $EMBER_SHARDED_PORT > /dev/null 2>&1 &
-$EMBER_BIN --port $EMBER_CONCURRENT_PORT --concurrent > /dev/null 2>&1 &
+$EMBER_BIN --port $EMBER_SHARDED_PORT --no-grpc > /dev/null 2>&1 &
+$EMBER_BIN --port $EMBER_CONCURRENT_PORT --concurrent --no-grpc > /dev/null 2>&1 &
 redis-server --port $REDIS_PORT --daemonize yes --save "" --appendonly no > /dev/null 2>&1
 sleep 2
 
diff --git a/bench/compare-redis.sh b/bench/compare-redis.sh
index 3223eb3d..183024b7 100755
--- a/bench/compare-redis.sh
+++ b/bench/compare-redis.sh
@@ -165,14 +165,15 @@ echo "threads:      $THREADS"
 echo ""
 
 # ember concurrent mode (DashMap-backed, fastest for GET/SET)
+# --no-grpc avoids gRPC port conflict when running multiple instances
 echo "starting ember concurrent on port $EMBER_CONCURRENT_PORT..."
-"$EMBER_BIN" --port "$EMBER_CONCURRENT_PORT" --concurrent > /dev/null 2>&1 &
+"$EMBER_BIN" --port "$EMBER_CONCURRENT_PORT" --concurrent --no-grpc > /dev/null 2>&1 &
 EMBER_CONCURRENT_PID=$!
 wait_for_server "$EMBER_CONCURRENT_PORT" "ember-concurrent"
 
 # ember sharded mode (channel-based, supports all data types)
 echo "starting ember sharded ($CPU_CORES shards) on port $EMBER_SHARDED_PORT..."
-"$EMBER_BIN" --port "$EMBER_SHARDED_PORT" > /dev/null 2>&1 &
+"$EMBER_BIN" --port "$EMBER_SHARDED_PORT" --no-grpc > /dev/null 2>&1 &
 EMBER_SHARDED_PID=$!
 wait_for_server "$EMBER_SHARDED_PORT" "ember-sharded"