Conclusion

The MegaRAID SATA 300-8X has performed generally well in our tests. It was especially good in the patterns that emulated the load on a file and web server.

The mirroring arrays are all right, too, but it was not all so well with RAID5. The XOR processor may be too slow or there may be some other reason, but the performance of the RAID5 array does not depend on the number of disks per array at high percentages of write requests. Alas, we only had four hard drives and could not examine this array type in more detail.

The only explanation that we can think of is that the controller was intended for 7200rpm SATA drives and the I/O processor was selected to match the typical access time of such drives. The high disk access time of the drives rather than the insufficient computational capacity of the XOR processor would be the bottleneck in that case.

So our recommendation is simple. Use this controller to build RAID1 and RAID10 arrays and make sure you have the LSIiBBU01 battery!