All four controllers are powerful and provide high storage performance as well as a plethora of features to provide both flexible, high-performance storage arrays for entry-level or for mid-range servers. All products support eight SAS ports, but can also be used to operate SATA drives, or a mixture of the two. Using SAS expanders, you can attach a multitude of drives; we consider the four candidates to be suitable for anything up to maybe 12 drives, since most of these cards were designed for internal drives. Have a look at models with external Mini-SAS ports if you need to hook up powerful storage appliances.

The ICP 5085BL is somewhat similar to Adaptec’s RAID 3805, but delivers better performance thanks to a faster XOR processor and double the cache memory, with a higher price. Both cards offer an impressive feature set and sophisticated management software, which has been fine-tuned over time, as Adaptec is one of the established players in the professional storage market. Atto requests double the money, for which you get fewer RAID features (with the exception of RAID 4 support), and you will have to fine-tune the controller card to have it perform better. It doesn’t do badly, but the default settings don’t enable a feature that boosts read performance. It did well with a degraded RAID 5 array, as the write performance did not drop as with the other products.

Raidcore offers the most comprehensive software, which is a result of its architecture: the software is host-based, and thus depends on the performance of the host machine. Unfortunately, Raidcore does not yet support RAID 6 (nor does Atto), but you can span RAID arrays across multiple Raidcore controllers, and the performance level of the I/O benchmarks was excellent on our dual processor Xeon test system. Transfer rates are high, but the other controllers typically beat Raidcore in this benchmark.

If you don’t mind the storage controller taxing the host system with XOR calculation, and if you can live with limited operating system support, Ciprico/Raidcore will give you excellent bang for the buck. Adaptec will give you better overall performance in some areas, and it is very reasonably priced.