1. A snoop filter apparatus associated with a processing unit of a computing environment having multiple processing units for supporting cache coherency in said computing environment, snoop filter apparatus comprising: a plurality of inputs, each receiving a snoop request from a dedicated memory writing source in said computing environment; a snoop filter means provided for each input for concurrently filtering received respective snoop requests from respective dedicated memory writing sources, each snoop filter means implementing one or more parallel operating sub-filter elements each for processing received snoop requests and forwarding a subset thereof to said associated processing unit, whereby as a result of said concurrent filtering, a number of snoop requests forwarded to a processing unit is significantly reduced thereby increasing performance of said computing environment.