diff --git a/config.json b/config.json
index 0d0d13e..ef4c79e 100644
--- a/config.json
+++ b/config.json
@@ -14,6 +14,7 @@
     "obfs": "tls1.2_ticket_auth_compatible",
     "obfs_param": "",
     "speed_limit_per_con": 0,
+    "speed_limit_per_user": 0,
 
     "dns_ipv6": false,
     "connect_verbose_info": 0,
diff --git a/shadowsocks/eventloop.py b/shadowsocks/eventloop.py
index e36f858..6e2f22f 100644
--- a/shadowsocks/eventloop.py
+++ b/shadowsocks/eventloop.py
@@ -53,7 +53,7 @@ EVENT_NAMES = {
 }
 
 # we check timeouts every TIMEOUT_PRECISION seconds
-TIMEOUT_PRECISION = 5
+TIMEOUT_PRECISION = 2
 
 
 class KqueueLoop(object):
diff --git a/shadowsocks/tcprelay.py b/shadowsocks/tcprelay.py
index 7f2d3c9..fcaadb0 100644
--- a/shadowsocks/tcprelay.py
+++ b/shadowsocks/tcprelay.py
@@ -133,6 +133,7 @@ class TCPRelayHandler(object):
         self._client_address = local_sock.getpeername()[:2]
         self._accept_address = local_sock.getsockname()[:2]
         self._user = None
+        self._user_id = server._listen_port
 
         # TCP Relay works as either sslocal or ssserver
         # if is_local, this is sslocal
@@ -238,6 +239,7 @@ class TCPRelayHandler(object):
 
     def _update_user(self, user):
         self._user = user
+        self._user_id = struct.unpack('<I', user)[0]
 
     def _update_activity(self, data_len=0):
         # tell the TCP Relay we have activities recently
@@ -754,6 +756,7 @@ class TCPRelayHandler(object):
             return
 
         self.speed_tester_u.add(len(data))
+        self._server.speed_tester_u(self._user_id).add(len(data))
         ogn_data = data
         if not is_local:
             if self._encryptor is not None:
@@ -850,6 +853,7 @@ class TCPRelayHandler(object):
             return
 
         self.speed_tester_d.add(len(data))
+        self._server.speed_tester_d(self._user_id).add(len(data))
         if self._encryptor is not None:
             if self._is_local:
                 try:
@@ -947,10 +951,11 @@ class TCPRelayHandler(object):
                     return True
             if event & (eventloop.POLL_IN | eventloop.POLL_HUP):
                 if not self.speed_tester_d.isExceed():
-                    handle = True
-                    self._on_remote_read(sock == self._remote_sock)
-                    if self._stage == STAGE_DESTROYED:
-                        return True
+                    if not self._server.speed_tester_d(self._user_id).isExceed():
+                        handle = True
+                        self._on_remote_read(sock == self._remote_sock)
+                        if self._stage == STAGE_DESTROYED:
+                            return True
             if event & eventloop.POLL_OUT:
                 handle = True
                 self._on_remote_write()
@@ -962,10 +967,11 @@ class TCPRelayHandler(object):
                     return True
             if event & (eventloop.POLL_IN | eventloop.POLL_HUP):
                 if not self.speed_tester_u.isExceed():
-                    handle = True
-                    self._on_local_read()
-                    if self._stage == STAGE_DESTROYED:
-                        return True
+                    if not self._server.speed_tester_u(self._user_id).isExceed():
+                        handle = True
+                        self._on_local_read()
+                        if self._stage == STAGE_DESTROYED:
+                            return True
             if event & eventloop.POLL_OUT:
                 handle = True
                 self._on_local_write()
@@ -1048,6 +1054,9 @@ class TCPRelay(object):
         self.server_users = {}
         self.server_user_transfer_ul = {}
         self.server_user_transfer_dl = {}
+        self.mu = False
+        self._speed_tester_u = {}
+        self._speed_tester_d = {}
         self.update_users_protocol_param = None
         self.update_users_acl = None
         self.server_connections = 0
@@ -1122,6 +1131,7 @@ class TCPRelay(object):
             protocol_param = self._config['protocol_param']
         param = common.to_bytes(protocol_param).split(b'#')
         if len(param) == 2:
+            self.mu = True
             user_list = param[1].split(b',')
             if user_list:
                 for user in user_list:
@@ -1164,6 +1174,22 @@ class TCPRelay(object):
             self.server_user_transfer_dl[user] += transfer + self.server_transfer_dl
             self.server_transfer_dl = 0
 
+    def speed_tester_u(self, uid):
+        if uid not in self._speed_tester_u:
+            if self.mu: #TODO
+                self._speed_tester_u[uid] = SpeedTester(self._config.get("speed_limit_per_user", 0))
+            else:
+                self._speed_tester_u[uid] = SpeedTester(self._config.get("speed_limit_per_user", 0))
+        return self._speed_tester_u[uid]
+
+    def speed_tester_d(self, uid):
+        if uid not in self._speed_tester_d:
+            if self.mu: #TODO
+                self._speed_tester_d[uid] = SpeedTester(self._config.get("speed_limit_per_user", 0))
+            else:
+                self._speed_tester_d[uid] = SpeedTester(self._config.get("speed_limit_per_user", 0))
+        return self._speed_tester_d[uid]
+
     def update_stat(self, port, stat_dict, val):
         newval = stat_dict.get(0, 0) + val
         stat_dict[0] = newval