Summing this test session up, we can say that the new 9690SA controller series from LSI 3ware is just perfect for server systems. This controller shows very good and stable performance in IOMeter: Database, especially when writing to RAID5 and RAID6 arrays. It does very well with mirror arrays (choosing the disk that takes less time to access the requested data block and reading sequential data from both disks of a mirror) and is good at multithreaded operations.
This controller is not a good choice for achieving a high linear speed, though. Its architecture copes well with lots of diverse operations but has a top speed limitation of about 650MBps. And one more thing: if you are running a RAID6 array on this controller, avoid having two failed HDDs in it. This will be dangerous for your data (a failure of a third disk will ruin the array) and the write speed will be awfully law.
But what if you need the highest linear speed possible? Just stay tuned for our upcoming RAID controller reviews!