Swap Device & Unix Disk Buffer

Does anyone know if when the Swap Device / Page file in unix is carrying out Page / Swap In's and Page / Swap outs, does it go through the Unix Disk Cache ( I am presuming raw partitions are not being used ) ?

Therefore if there is paging activity on a system ( measured by sar -p, sar -g and vmstat -p ), should this activity also be reflected at the Unix Disk Cache level ( measured through sar -b ) and ultamately at the disk io level ( measured through sar -d and iostat ).

Alternatively does the swap partition bypass the Unix Cache altogether ?

One other question - how does onboard disk caches ( i.e. chips embedded with the disk itself ) effect the unix cache and how do you measure this activity ?