Describe a difference between pyzmq.asyncio and aiozmq implementation

README.rst

@@ -69,6 +69,23 @@ Low-level request-reply example::
     asyncio.get_event_loop().run_until_complete(go())
 
 
+Comparison to pyzmq
+-------------------
+
+`zmq.asyncio` provides a *asyncio compatible loop* implementation.
+
+But it's based on `zmq.Poller` which doesn't work well with massive
+non-zmq sockets usage.
+
+E.g. if you build a web server for handling at least thousands of
+parallel web requests (1000-5000) `pyzmq` internal Poller will be slow.
+
+`aiozmq` works with epoll natively, it doesn't need custom loop
+implementation and cooperates pretty weel with `uvloop` for example.
+
+For details see https://github.com/zeromq/pyzmq/issues/894
+
+
 Requirements
 ------------