diff --git a/light8/dmxserver.py b/light8/dmxserver.py
--- a/light8/dmxserver.py
+++ b/light8/dmxserver.py
@@ -42,36 +42,53 @@ class XMLRPCServe(xmlrpc.XMLRPC):
         self.combinedlevels=[] # list of levels, after max'ing the clients
         self.clientschanged=1 # have clients sent anything since the last send?
         self.options=options
+        self.lastupdate=0 # time of last dmx send
+        self.laststatsprint=0  # time
+
+        # desired seconds between sendlevels() calls
+        self.calldelay=1/options.updates_per_sec 
 
         print "starting parport connection"
         self.parportdmx=ParportDMX()
         self.parportdmx.golive()
 
-        # start the loop
-        self.updatefreq=Updatefreq()
+        self.updatefreq=Updatefreq() # freq of actual dmx sends
         self.num_unshown_updates=None
         self.lastshownlevels=None
+        # start the loop
         self.sendlevels()
+
+        # the other loop
+        self.purgeclients()
         
-
     def purgeclients(self):
         
         """forget about any clients who haven't sent levels in a while
-        (5 seconds)"""
+        (5 seconds). this runs in a loop"""
+
+        purge_age=10 # seconds
+        
+        reactor.callLater(1,self.purgeclients)
+
         now=time.time()
         for cid,lastseen in self.lastseen.items():
-            if lastseen<now-5:
-                print "forgetting client %s (no activity for 5sec)" % cid
+            if lastseen<now-purge_age:
+                print ("forgetting client %s (no activity for %s sec)" %
+                       (cid,purge_age))
                 del self.clientlevels[cid]
                 del self.lastseen[cid]
                 del self.clientfreq[cid]
         
     def sendlevels(self):
-        reactor.callLater(1/20,self.sendlevels)
+        
+        """sends to dmx if levels have changed, or if we havent sent
+        in a while"""
+
+        reactor.callLater(self.calldelay,self.sendlevels)
+
         if self.clientschanged:
             # recalc levels
 
-            self.purgeclients()
             self.calclevels()
          
             if (self.num_unshown_updates is None or # first time
@@ -84,11 +101,16 @@ class XMLRPCServe(xmlrpc.XMLRPC):
             else:
                 self.num_unshown_updates+=1
 
-        if (self.num_unshown_updates-1)%50==0:
+        if time.time()>self.laststatsprint+2:
+            self.laststatsprint=time.time()
             self.printstats()
-            
-        self.sendlevels_dmx()
 
+        if self.clientschanged or time.time()>self.lastupdate+1:
+            self.lastupdate=time.time()
+            self.sendlevels_dmx()
+
+        self.clientschanged=0 # clear the flag
+        
     def calclevels(self):
         """combine all the known client levels into self.combinedlevels"""
         self.combinedlevels=[]
@@ -101,7 +123,6 @@ class XMLRPCServe(xmlrpc.XMLRPC):
                     x=max(x,cl)
             self.combinedlevels.append(x)
 
-
     def printlevels(self):
         """write all the levels to stdout"""
         print "Levels:","".join(["% 2d "%(x*100) for
@@ -110,7 +131,7 @@ class XMLRPCServe(xmlrpc.XMLRPC):
     def printstats(self):
         """print the clock, freq, etc, with a \r at the end"""
 
-        sys.stdout.write("dmxserver up at %s, [server %s] "%
+        sys.stdout.write("dmxserver up at %s, [polls %s] "%
                          (time.strftime("%H:%M:%S"),
                           str(self.updatefreq),
                           ))
@@ -119,7 +140,6 @@ class XMLRPCServe(xmlrpc.XMLRPC):
         sys.stdout.write("\r")
         sys.stdout.flush()
 
-    
     def sendlevels_dmx(self):
         """output self.combinedlevels to dmx, and keep the updates/sec stats"""
         # they'll get divided by 100
@@ -133,11 +153,13 @@ class XMLRPCServe(xmlrpc.XMLRPC):
     def xmlrpc_outputlevels(self,cid,levellist):
         """send a unique id for your client (name+pid maybe), then
         the variable-length dmx levellist (scaled 0..1)"""
-        self.clientlevels[cid]=levellist
-        self.clientschanged=1
-        if cid not in self.lastseen:
-            print "hello new client %s" % cid
-            self.clientfreq[cid]=Updatefreq()
+        if levellist!=self.clientlevels.get(cid,[]):
+            self.clientlevels[cid]=levellist
+            self.clientschanged=1
+            if cid not in self.lastseen:
+                print "hello new client %s" % cid
+                self.clientfreq[cid]=Updatefreq()
+                
         self.lastseen[cid]=time.time()
         self.clientfreq[cid].update()
         return "ok"
@@ -146,8 +168,12 @@ parser=OptionParser()
 parser.add_option("-f","--fast-updates",action='store_true',
                   help=('display all dmx output to stdout instead '
                         'of the usual reduced output'))
+parser.add_option("-r","--updates-per-sec",type='float',default=20,
+                  help=('dmx output frequency'))
 (options,songfiles)=parser.parse_args()
 
+print options
+
 print "starting xmlrpc server on port 8030"
 reactor.listenTCP(8030,server.Site(XMLRPCServe(options)))
 reactor.run()