should I change mysql platform for higher innodb_buffer_pool_size?
With a 160 GB database, it does not sound like a 10 GB cache is overkill, but it depends to some extent on the size of the active data as well. 

I suggest that you look at Rolando's post:
How large should be mysql innodb_buffer_pool_size?

In the particular case he discusses, there was too much memory allocated for the cache. However, he offers considerable detail on what to measure and how to refine the size of the cache.  

Some code snippets from Rolando's post:

Compute the Cache Size:

SELECT CEILING(Total_InnoDB_Bytes*1.6/POWER(1024,3)) RIBPS FROM
(SELECT SUM(data_length+index_length) Total_InnoDB_Bytes
FROM information_schema.tables WHERE engine='InnoDB') A;


After you reset the buffer size and restart the server, give it some time, then run this to see how usage is holding up:

SELECT (PagesData*PageSize)/POWER(1024,3) DataGB FROM
(SELECT variable_value PagesData
FROM information_schema.global_status
WHERE variable_name='Innodb_buffer_pool_pages_data') A,
(SELECT variable_value PageSize
FROM information_schema.global_status
WHERE variable_name='Innodb_page_size') B;