Best Innodb Buffer Pool Size for 8GB RAM?
I have four(4) old posts to demonstrate how to measure and size up the InnoDB Buffer Pool based on the amount of RAM on the DB Server and how much space is currently being taken up by data/index pages:


Apr 14, 2011 : What are the main differences between InnoDB and MyISAM?
Oct 22, 2012 : How much memory do I need for innodb buffer pool?
Oct 22, 1012 : How large should be mysql innodb_buffer_pool_size?
Apr 08, 2013 : MySQL performance impact of increasing innodb_buffer_pool_size


Please look over these posts, run the queries, and use good judgment. Why did I say to use good judgment ? If the ideal Buffer Pool Size is greater than 6GB (75% of your DB Server's RAM), the highest innodb_buffer_pool_size permissible would be 6G.

Give it a Try !!!