With the rise of Windows Home Server, VAIL, Aurora, the venerable Linux file servers (e.g. ones based on CentOS and Openfiler), and ZFS enabled OSes such as FreeBSD and OpenSolaris with their NAS derivatives (e.g. FreeNAS and EON ZFS Storage), users have a strong alternative to hardware RAID controllers. These operating systems have the ability to use raw disks and manage data redundancy without the use of RAID controllers.e7-8830
For smaller installations, such as 2-6 drive configurations, onboard Intel ICH10 or ICH10R controllers are a best bet due to their compatibility and very low cost. When drive counts expand, so must the servers SATA port count. With traditional RAID controllers, a user is limited to including ports physically located on the storage controller. Therefore to connect fourteen drives a user typically needs a sixteen port or greater RAID card because hardware RAID arrays generally cannot span different controllers. Using a software RAID or RAID-like solution one is not limited by these barriers and chip can utilize ports on motherboards as well as on add-in controllers.
The Intel SASUC8I is an Intel branded version of the LSI SAS3081E-R eight port SAS/ SATA controller. Effectively identical in specifications, the Intel card differentiates itself in two areas. First, it has an Intel firmware that is geared towards Intel servers with features such as a firmware update tool that works exclusively with EFI servers. The other main advantage is that the street price of the Intel SASUC8I is approximately $50 lower than the LSI SAS3081E-R counterpart. Luckily, the Intel firmware can be flashed with a DOS based tool to the LSI IT firmware (removes RAID settings making this a JBOD controller) or IR firmware (retains the RAID 0/1/1E/10E functionality). Once flashed, the main difference remaining is the $50 lower price for the Intel based part.
Both based on the venerable LSI 1068e controller, the Intel SASUC8I and LSI SAS3081E-R are very well supported by virtually every operating system. Common NAS operating systems such as Windows Server, OpenSolaris, FreeBSD, and Linux all support the LSI 1068e and therefore the controllers. The nice thing is that drivers are already included in most operating systems and I was pleasantly surprised that both OpenSolaris and FreeNAS 0.7.1 worked perfectly with the controller. OpenSolaris has good reason; many Sun servers shipped with LSI 1068e based controllers. Inclusion in the lightweight FreeNAS installation was a major bonus and really highlights the fact that this will be a controller that is supported for years to come.
A main drawback of the LSI 1068e is that it is a PCIe 1.0 part. Some will like and others will take issue with the PCIe x8 connector, mostly based on motherboard slot availability. For those users with only a PCIe x1 or x4 slot available, the Intel SASUC8I and LSI SAS3081E-R may run into physical constraints. On the other hand, plenty of mITX motherboards support a PCIe x8 or x16 physical slot that can accept the Intel SASUC8I or LSI SAS3081E-R which makes it fairly versitile. In fact, the Intel SASUC8I and LSI SAS3081E-R are low profile cards so they can be used in half-height PCIe slots.
Perhaps the “killer” feature of the Intel SASUC8I and LSI SAS3081E-R could be the ability to use the controller with the low-cost HP SAS Expander (v2.02 tested). Effectively, one can connect one HP SAS Expander to one of the four-port connectors and another to the second four-port connector as the cards have two SFF-8087 mini-SAS ports. For approximately $240-340 per HP SAS Expander and $170 for the Intel SASUC8I and one has a $750-$950 solution capable of connecting well in excess of 60 drives. For reference $750 is approximately the street price of a quality Intel IOP348 based 12-port controller. Simply put, this combination is one of the best values for connecting masses of SATA disks to a system where raw performance is not an issue.
In testing, I consistently saw read and write speeds in excess of 400MB/s even over a HP SAS Expander using FreeNAS 0.7.1 connected to only one of the two SFF-8087 ports on the controller. Generally speaking, 400MB/s is enough to saturate the available external I/O bandwidth of most lower-end servers especially with the overhead involved with link aggregation.
Another really amazing feature of these cards is their MTBF numbers. The Intel SASUC8I’s MTBF is rated at 1,252,830 hours. Just for a point of reference, the Adaptec 5805 is rated at 873,402 hours.
The other major drawback of the LSI 1068e is that one does not get RAID 5/6 support or a battery backed write cache. As a result, higher-end hardware RAID features are absent from these controllers. From a practical perspective, if there is a need for running hardware RAID 6 for example, because you want one array with volumes passed to different operating systems (where using software RAID is more problematic), the Intel SASUC8I and LSI SAS3081E-R are probably not a best bet. If you are planning to use software RAID, the Intel SASUC8I and LSI SAS3081E-R combine compatibility with a very low price point.
Based on the venerable LSI 1068e chipset, both the Intel SASUC8I and LSI SAS3081E-R provide exceptional compatibility with relatively low prices. Although high-end RAID card features are absent from these cards, the low cost and ability to utilize the Intel SASUC8I and LSI SAS3081E-R with the HP SAS Expander make them a best bet for those looking to make 7+ drive home servers where onboard SATA ports are not sufficient.