1. A method for preforming data prefetch in a multiprocessor system, wherein said multiprocessor system includes a plurality of processors, each having a cache memory, said method comprising: issuing a plurality of prefetch requests by a requesting processor; in response to said plurality of prefetch requests miss in cache memory of said requesting processor, merging said plurality of prefetch requests into a combined prefetch request; sending said combined prefetch request to cache memories of all non-requesting processors; and in response to a combined clean response from cache memories of all non-requesting processors, obtaining data for said combined prefetch request from a system memory.