DrupalDatabaseCache::set Devel Module I seem to be getting slow speeds with 
DrupalDatabaseCache::set and DrupalDatabaseCache::getMultiple

i am using drupal 7 and am on a Virtual Private Server on Dreamhost which is running Fast CGI and xchache

Any tips on how to get these requests (40+ milliseconds) down under 5mills?

there are some other querries that are above 5 milliseconds
user_roles, menu_get_item, menu_item_visibility_load etc..

any tips for overall improvement in the time querries take to load?
Best Option: Use a non DB cache backend like Memcache
Next Best: Use a MySQL derivative that supports blob columns in a memory table and convert all cache tables to be of the type memory. Be sure to rebuild the indexes as BTREE's instead of HASH after converting to MEMORY. More details on this can be seen in this presentation: http://www.percona.com/resources/technical-presentations/drupal-and-mysql-performance-percona-live-mysql-webinar
Still good: Follow the directions here: Drupal 7: Database select query FROM cache_bootstrap brings server down


Note that all 3 of the above options are independent from each other; so you can do all 3. Also noted that the answer in #3, his database server was configured reasonably well; you might need to tune InnoDB in order to get better performance out of your's.

EDIT:
Also checkout my guide on tuning D7 https://docs.google.com/presentation/d/1AgnurTWsWdMAFjfFmSU7mk2zfJu8jG_KmVdZ7-o6Pok/edit#slide=id.p