We need to price hardware for three new systems. One system is an Accounting package, another is a compliance package and a third is a trading system. The trade system in particular needs to be high-performance. Being new to the SAN world I don't know if RAID configurations used for non-SAN configurations apply to SANs.

For the trade system if we did not go with a SAN my configuration would be as follows:
NOTE: The smallest drives we can purchase are 72GB and the total database size will probably be under 20GB after a year or so. Data retrieval speed is key with this system.

Data - RAID 10 (15k rpm drives) (4 72GB for approximately 144GB usable space).
Logs - RAID 10 (15k)
Tempdb - RAID 1 (15k)
Backup - RAID 1 or 5

Data on a dedicated controller
OS & Logs share a controller
Tempdb and Backups share a controller

The same configuration would be used for the accounting system, although system performance, while important, is not a critical.

Our SAN is EMC. How would the above configuration translate to a SAN and what are the performance differences in terms of read/write speed on a SAN vs. internal SCSI drives?

Thanks, Dave