Abstract: The current performance bottleneck of SAN storage system based on FC network mainly exists in the operations to access disk Given in this paper is a new method to improve the performance of FC SAN storage system, which is concluded based on the results of all kinds of file system I/O operation workload It divides all I/O operations into three types: large file read/write operation, small file read/write operation, and all other file attributes operation All large file read/write operations will continue to use previous I/O path, but others will operate with RAMDisk based on memory The results of the test show that the access rate of FC SAN system based on RAMDisk can approximate wire speed