mount.ocfs2(8) allows users to specify the level of cache coherency between nodes. By default the file system operates in full coherency mode that also serializes the direct I/Os. While this mode is technically correct, it limits the I/O thruput in a clustered database. This mount option allows the user to limit the cache coherency to only the buffered I/Os to allow multiple nodes to do concurrent direct writes to the same file. This feature works with Linux kernel 2.6.37 and later.
According to the above, you can play with the cache coherency in order to increase bandwidth.