• I have seen that happen many times, and it was always due to poor IO performance.

    You would think that newer would be faster, but that is often not the case. I have seen many brand new servers where the IO performance was horrible.

    I usually do extensive IO benchmarking using SQLIO before I even install SQL Server. There are many articles about how to do this posted here and other places.

    An important thing to be aware of with IO benchmarking is that you need to make your test files big enough to overcome the size of the RAID cache and to make sure you are seeing the true performance of the drives. Also, you need to test both reads and writes and random and sequential at various IO block sizes. Most IO testing software concentrates on 4K blocks, which is good for file servers, and defaults to small test files, like 100 MB. SQL Server does IO in much larger blocks, usually 64K. I am usually most interested in the performance of 64K reads and writes, especially random IO. I like to use very large test files, 20GB to 100 GB, especially if it is on a SAN with a large cache.