optimization by exploiting internal parallelism of flash based solid state drives u201d pvldb 5 2011 h roh s park s kim m shin and s w lee referred to as u201c psync i o u201d the contents of which are hereby incorporated by reference internally psync i o uses multiple asynchronous i o calls and waits until all i o 39 s are completed a controller 200 may processes requests originating from request queue 202 which may comprise insert update and or lookup operations in batches the controller 200 first processes all requests that can be instantly served in memory then the controller 200 processes lookup requests which need reading from the ssd to leverage channel level parallelism maximally the controller should pick requests that go to different channels based on determining a mapping between pages and channels as discussed above a channel estimator may be developed to estimate the mapping between read requests and channels using these estimates a set of k requests with k corresponding to the size of the ssd 39 s ncq such that the number of requests picked for any channel is minimized while it is desirable to use as much concurrency as the ncq can provide it is important to optimally exploit channel parallelism the algorithm underlying request selection works as follows in block.