Optimal SQL Server 2012 Disk Configuration I will be installing SQL Server 2012 on a new Dell T430 server containing four (4) physical 15K SAS 6Gbps disk drives using a PERC H730P RAID Controller and RAID 1. Since this will be the first time I've installed SQL Server 2012, can someone please recommend an optimal configuration for disk allocations. My thoughts were to install the OS, programs and main databases on one physical drive and put the transaction and logs (both TEMPDB and main DBs) on the other disk drive. Would someone have a better recommendation so I can get the best performance out of the limited resources? Thanks.
Best practises state that the optimal storage configuration is to have at least three volumes: One for the OS, another for the Database files and the third for transaction logs and to that you should add a fourth one for tempdb. 

Sometimes you just don't live in an optional world though. If you cant possibly get a third pair of disks, I would recommend that you benchmark different configuration using SQLIO. In your case you might be able to squeeze more I/O from the raid controller, without sacrificing redundancy by setting all four disks up as a single volume using RAID 1+0 and create four partitions on that for the os, data, log and tempdb. Only a benchmark will tell.