On my windows 2 cpu server with 20 disks, disk queue lengths exceed 40. Windows perfmon and IOmeter benchmarks give me 0.9K IOPs for write and 2K for reads, 8K OLTP block size. #disks : 20 : 36 GB, 15K rpm, U320 scsi with two dual channel controllers with 256 MB cache each. I am moving to a SAN. How can I get double my current IO performance. In addition I also want a development/failover system with half the performance of production. production data size : 400 GB development data size : 400 GB temp table space : 100 GB each for production and develop. Log file : 100 GB each for development and production. In addition I have an application server which users upload data ( hence mainly writes). files are large : 50-100MB in uploads. All cases, 20 simultaneous access the SAN. My solution : 28, 73 GB 15K for production + temp tablespace. 28, 73 GB 10K for development/temp table space. 4 disks 146 GB, 10K for logs ( prod and develop) 8 disks 146 GB, 10K for application server. However the cost is 50% more than my budget. Also included is a tape library and d2d backup to tape. d2d window : 5 hrs. d2t window : 10 hrs. data size = 1 TB, compression ~ 20%.