PageSize

http://www.yiiframework.com/extension/pagesize

Extract and put PageSize folder into extensions directory Place the widget just before the GridView

<div align="right" class="row">
<?php 
$this->widget('application.extensions.PageSize.PageSize', array(
        'mGridId' => '<grid-id>', //Gridview id
    'mPageSize' => @$_GET['pageSize'],
        'mDefPageSize' => Yii::app()->params['defaultPageSize'],
        'mPageSizeOptions'=>Yii::app()->params['pageSizeOptions'],// Optional, you can use with the widget default
)); 
?>
</div>

// Add below to your model search()
'pagination' => array(  'pageSize'=>Yii::app()->user->getState('pageSize',Yii::app()->params['defaultPageSize']),
)

// Add below to your config/main.php params
'defaultPageSize' = 10,
'pageSizeOptions'=>array(10=>10,20=>20,50=>50,100=>100),

Thats it.