Can you suggest any alternative for Statistics module? We have a pretty descend traffic to our Drupal website, approximately 600 page views per minute. We have enabled the Drupal statistics module for storing the node page views.

At peek traffic hours, we observed a high usage of Disk I/O wait, and we doubt that it is due to statistics module. Please correct me if am wrong. If yes, kindly suggest some alternative method to implement node view counter.
Have a look at the Visitors module. Here are some reports you get from it:


  
  View pages that have recently been visited.
  View pages that have been hit frequently.
  View pages count per month, day of month, day of week, hour.
  ...
  


Especially these reports should be what you're looking for (it includes hits for paths corresponding to a view):


Top pages (table with columns Title, Path and nr of Hits).
Recent hits (table with columns Date of visit, Title, Path and User ID of the visitor).


Checkout the above (source) links to get an idea of which data are available.

The demo site contains some sample reports (charts) available to anonymous users also. This demo site also shows some additional blocks with reports also created by the Visitors module module.

You may also want to look at the visitors_schema to get an idea of the data that actually get logged (recorded) by this module.

In case it's not a perfect fit, it's probably a very good starting point for some custom reporting. Either via a custom module that would simply have to query the data maintained by the Visitors module. Or via a straight forward custom report created with the Forena module.

Disclosure: I'm the maintainer of the Visitors module,
and co-maintainer of the Forena module.