Affinity Mask and Affinity I/O Mask Using: SQL Server 2008 R2

Under what circumstances would you set the Affinity Mask and Affinity I/O Mask options in sp_configure in SQL Server?

We are currently running on a machine with 16 cores dedicated to SQL Server.  We are also seeing slowness in our I/O operations.  Some writes (insert 1 row) can take up to 500 ms.  We would like to support many writes per second.  The process that inserts data can spawn up to 4 threads for executing the insert operations.

I'm considering dedicating 8 cores to the affinity mask and the other 8 to affinity I/O mask.  

Is this recommended?
I'd consider many other options before I played with these

Some things to check here on SO: https://stackoverflow.com/a/2009693/27535

Additionally...


indexes: are your writes scanning not seeking?
key: do you have GUIDs as clustered indexes (bad idea!)
triggers: no emails being sent on INSERT or CURSORs?
disk layout: separate fast RAIDs for data and logs, per database?
autoshrink/autoclose + associated file growth
unmaintained statistics and indexes
..


Basically, your problem will be poor design poor indexing or poor hardware...