diff --git a/develop/GMap.js b/develop/GMap.js
index 3c78a02..021f36f 100644
--- a/develop/GMap.js
+++ b/develop/GMap.js
@@ -1,13 +1,15 @@
 import React from 'react';
 import compose from 'recompose/compose';
 import defaultProps from 'recompose/defaultProps';
-import withState from 'recompose/withState';
+import withStateSelector from './utils/withStateSelector';
 import withHandlers from 'recompose/withHandlers';
-// import withPropsOnChange from 'recompose/withPropsOnChange';
+import withState from 'recompose/withState';
+import withPropsOnChange from 'recompose/withPropsOnChange';
+import ptInBounds from './utils/ptInBounds';
 import GoogleMapReact from '../src';
 import SimpleMarker from './markers/SimpleMarker';
 
-import { susolvkaCoords, markersData } from './data/fakeData';
+import { susolvkaCoords, generateMarkers } from './data/fakeData';
 
 export const gMap = ({
   style, hoverDistance, options,
@@ -53,8 +55,14 @@ export const gMapHOC = compose(
       flex: 1,
     },
   }),
+
   // withState so you could change markers if you want
-  withState('markers', 'setMarkers', markersData),
+  withStateSelector(
+    'markers',
+    'setMarkers',
+    ({ route: { markersCount = 20 } }) => markersCount,
+    (markersCount) => generateMarkers(markersCount)
+  ),
   withState('hoveredMarkerId', 'setHoveredMarkerId', -1),
   withState('mapParams', 'setMapParams', { center: susolvkaCoords, zoom: 10 }),
   // describe events
@@ -69,6 +77,14 @@ export const gMapHOC = compose(
       setHoveredMarkerId(-1);
     },
   }),
+  withPropsOnChange(
+    ['markers', 'mapParams'],
+    ({ markers, mapParams: { bounds } }) => ({
+      markers: bounds
+        ? markers.filter(m => ptInBounds(bounds, m))
+        : [],
+    })
+  )
 );
 
 export default gMapHOC(gMap);
diff --git a/develop/Layout.js b/develop/Layout.js
index ef9f817..5875590 100644
--- a/develop/Layout.js
+++ b/develop/Layout.js
@@ -1,17 +1,18 @@
 import React, { Component } from 'react';
 import compose from 'recompose/compose';
+import { Link } from 'react-router';
 import defaultProps from 'recompose/defaultProps';
 import layoutStyles from './Layout.sass';
-import GMap from './GMap';
 // for hmr to work I need the first class to extend Component
 export class Layout extends Component { // eslint-disable-line
   render() {
-    const { styles: { layout, header, main, footer, logo } } = this.props;
+    const { styles: { layout, header, main, footer, logo, links } } = this.props;
     return (
       <div className={layout}>
         <header className={header}>
-          <div>
-            Clustering example google-map-react (zoom, move to play with)
+          <div className={links}>
+            <Link to="/">Multi Markers</Link>
+            <Link to="/hoveroptim">Hover optim</Link>
           </div>
           <div>
             <a href="https://github.com/istarkov/google-map-clustering-example">
@@ -20,7 +21,7 @@ export class Layout extends Component { // eslint-disable-line
           </div>
         </header>
         <main className={main}>
-          <GMap />
+          {this.props.children}
         </main>
         <footer className={footer}>
           <div>
diff --git a/develop/Layout.sass b/develop/Layout.sass
index 426518f..4e00477 100644
--- a/develop/Layout.sass
+++ b/develop/Layout.sass
@@ -15,6 +15,10 @@
   a
     color: #fff
 
+.links
+  a
+    margin-right: 20px
+
 .logo
   width: 1.3em
   height: 1.3em
diff --git a/develop/Main.js b/develop/Main.js
index 71c2fba..33d6db6 100644
--- a/develop/Main.js
+++ b/develop/Main.js
@@ -1,11 +1,22 @@
 // file: main.jsx
 import React from 'react';
 import { render } from 'react-dom';
-import Layout from './Layout.js';
+import { Router, Route, IndexRoute, browserHistory } from 'react-router';
+import Layout from './Layout';
+import GMap from './GMap';
 
 import 'normalize.css/normalize.css';
 import './Main.sass';
 
 const mountNode = document.getElementById('app');
 
-render(<Layout />, mountNode);
+render(
+  <Router history={browserHistory}>
+    <Route path="/" component={Layout}>
+      <Route markersCount={200} path="hoveroptim" component={GMap} />
+      <IndexRoute markersCount={20} component={GMap} />
+    </Route>
+  </Router>
+  ,
+  mountNode
+);
diff --git a/develop/data/fakeData.js b/develop/data/fakeData.js
index fe0eaf7..a00e596 100644
--- a/develop/data/fakeData.js
+++ b/develop/data/fakeData.js
@@ -1,17 +1,16 @@
-
-const TOTAL_COUNT = 20;
-
 export const susolvkaCoords = { lat: 60.814305, lng: 47.051773 };
 
-export const markersData = [...Array(TOTAL_COUNT)].fill(0) // fill(0) for loose mode
-  .map((__, index) => ({
-    id: index,
-    lat: susolvkaCoords.lat +
-      0.01 * index *
-      Math.sin(30 * Math.PI * index / 180) *
-      Math.cos(50 * Math.PI * index / 180) + Math.sin(5 * index / 180),
-    lng: susolvkaCoords.lng +
-      0.01 * index *
-      Math.cos(70 + 23 * Math.PI * index / 180) *
-      Math.cos(50 * Math.PI * index / 180) + Math.sin(5 * index / 180),
-  }));
+
+export const generateMarkers = (count) =>
+  [...Array(count)].fill(0) // fill(0) for loose mode
+    .map((__, index) => ({
+      id: index,
+      lat: susolvkaCoords.lat +
+        0.01 * index *
+        Math.sin(30 * Math.PI * index / 180) *
+        Math.cos(50 * Math.PI * index / 180) + Math.sin(5 * index / 180),
+      lng: susolvkaCoords.lng +
+        0.01 * index *
+        Math.cos(70 + 23 * Math.PI * index / 180) *
+        Math.cos(50 * Math.PI * index / 180) + Math.sin(5 * index / 180),
+    }));
diff --git a/develop/utils/createEagerFactory.js b/develop/utils/createEagerFactory.js
new file mode 100644
index 0000000..56dc0a0
--- /dev/null
+++ b/develop/utils/createEagerFactory.js
@@ -0,0 +1,12 @@
+import createEagerElementUtil from './utils/createEagerElementUtil';
+import isReferentiallyTransparentFunctionComponent
+  from './isReferentiallyTransparentFunctionComponent';
+
+const createFactory = type => {
+  const isReferentiallyTransparent =
+    isReferentiallyTransparentFunctionComponent(type);
+  return (p, c) =>
+    createEagerElementUtil(false, isReferentiallyTransparent, type, p, c);
+};
+
+export default createFactory;
diff --git a/develop/utils/isReferentiallyTransparentFunctionComponent.js b/develop/utils/isReferentiallyTransparentFunctionComponent.js
new file mode 100644
index 0000000..4c9d254
--- /dev/null
+++ b/develop/utils/isReferentiallyTransparentFunctionComponent.js
@@ -0,0 +1,15 @@
+const isClassComponent = Component => Boolean(
+  Component &&
+  Component.prototype &&
+  typeof Component.prototype.isReactComponent === 'object'
+);
+
+const isReferentiallyTransparentFunctionComponent = Component => Boolean(
+  typeof Component === 'function' &&
+  !isClassComponent(Component) &&
+  !Component.defaultProps &&
+  !Component.contextTypes &&
+  !Component.propTypes
+);
+
+export default isReferentiallyTransparentFunctionComponent;
diff --git a/develop/utils/ptInBounds.js b/develop/utils/ptInBounds.js
new file mode 100644
index 0000000..59ad1f3
--- /dev/null
+++ b/develop/utils/ptInBounds.js
@@ -0,0 +1,13 @@
+const ptInSect = (x, a, b) => (x - a) * (x - b) <= 0;
+
+export default ({ nw, se }, pt) => {
+  const lngs = nw.lng < se.lng
+     ? [[nw.lng, se.lng]]
+     : [[nw.lng, 180], [-180, se.lng]];
+
+
+  return (
+    ptInSect(pt.lat, se.lat, nw.lat) &&
+    lngs.some(([lngFrom, lngTo]) => ptInSect(pt.lng, lngFrom, lngTo))
+  );
+};
diff --git a/develop/utils/utils/createEagerElementUtil.js b/develop/utils/utils/createEagerElementUtil.js
new file mode 100644
index 0000000..f9167aa
--- /dev/null
+++ b/develop/utils/utils/createEagerElementUtil.js
@@ -0,0 +1,26 @@
+import React from 'react';
+
+const createEagerElementUtil = (
+  hasKey,
+  isReferentiallyTransparent,
+  type,
+  props,
+  children
+) => {
+  if (!hasKey && isReferentiallyTransparent) {
+    if (children) {
+      return type({ ...props, children });
+    }
+    return type(props);
+  }
+
+  const Component = type;
+
+  if (children) {
+    return <Component {...props}>{children}</Component>;
+  }
+
+  return <Component {...props} />;
+};
+
+export default createEagerElementUtil;
diff --git a/develop/utils/withStateSelector.js b/develop/utils/withStateSelector.js
new file mode 100644
index 0000000..f490ab9
--- /dev/null
+++ b/develop/utils/withStateSelector.js
@@ -0,0 +1,42 @@
+import { Component } from 'react';
+import createEagerFactory from './createEagerFactory';
+import { createSelector } from 'reselect';
+
+const withStateSelector = (stateName, stateUpdaterName, ...selectorArgs) =>
+  BaseComponent => {
+    const factory = createEagerFactory(BaseComponent);
+    return class extends Component {
+      selector = createSelector(...selectorArgs);
+      state = {
+        stateValue: this.selector(this.props),
+      };
+
+      updateStateValue = (updateFn, callback) => (
+        this.setState(({ stateValue }) => ({
+          stateValue: typeof updateFn === 'function'
+            ? updateFn(stateValue)
+            : updateFn,
+        }), callback)
+      );
+
+      componentWillReceiveProps(nextProps) {
+        // reselect memoize result
+        const nextStateValue = this.selector(nextProps);
+        if (nextStateValue !== this.state.stateValue) {
+          this.setState({
+            stateValue: nextStateValue,
+          });
+        }
+      }
+
+      render() {
+        return factory({
+          ...this.props,
+          [stateName]: this.state.stateValue,
+          [stateUpdaterName]: this.updateStateValue,
+        });
+      }
+    };
+  };
+
+export default withStateSelector;
diff --git a/package.json b/package.json
index 2ec93d9..6c26063 100644
--- a/package.json
+++ b/package.json
@@ -78,7 +78,9 @@
     "react-addons-test-utils": "^15.1.0",
     "react-dom": "^15.1.0",
     "react-motion": "^0.4.4",
+    "react-router": "^2.4.1",
     "recompose": "^0.19.0",
+    "reselect": "^2.5.1",
     "rimraf": "^2.4.3",
     "sass-loader": "^3.2.0",
     "style-loader": "^0.13.1",