In a steady and commonsensical way Adaptec has come to manufacture RAID controllers for hard disk drives with SAS interface. Having released a few trial models, the company has begun to make controllers based on a unified serial architecture. These are inexpensive entry-level 4-port controllers of the first and second series (the series number is the first numeral in the model name) and mainstream third series controllers. Of course, the high-performance fifth series, which is the current peak in the evolution of Adaptec’s controllers, is a logical continuation of the previous products.
It is interesting to compare Adaptec’s controller series, by the way. The first series has no integrated processor and cache and is equipped with a PCI Express x4 interface. The third series comes with 500MHz or 800MHz Intel 80333 processors and with 128 to 256 megabytes of cache; the 4-port models have PCI Express x4 while the 8-port model has PCI Express x8 (by the way, we tested the third series ASR-3405 model earlier). The fifth series has transitioned to PCI Express x8 entirely and every model, save for the 4-port one, is equipped with 512 megabytes of cache (the cache of the junior model ASR-5405 is cut down to 256MB). Every controller of the fifth series uses the most powerful processor currently installed on RAID controllers: it is a dual-core chip clocked at 1.2GHz.
We have not mentioned the second series because it seems to be a simplification of the fifth rather than of the third series. Both its models have four ports, i.e. one internal SFF-8087 or one external SFF-8088 connector, and PCI Express x8 together with a dual-core processor. The processor frequency is 800MHz, which is lower than in the fifth series. The second series also has a smaller cache, 128MB, probably to be positioned as junior relative to the third series. Another indication of the origin of the second series is that its models support Adaptec Intelligent Power Management that was first featured in the fifth series. This technology means that unused disks are shut down or switched into sleep mode in order to save power. And the distinguishing feature of the second series is that it only supports RAID0, 1 and 10 array types. It cannot work with parity-based arrays (RAID5, RAID6 and their two-level derivatives).
So, we are going to test the Adaptec’s fifth series model called ASR-5805.