When we started receiving 12Gbps SAS products in the summer of 2013, we were met with typical products such as the Adaptec ASR-8885 RAID Adapter, the LSI SAS 9300-8e HBA and the HGST SSD800MM SSD. Each of these products delivered excellent performance that far outpaced the 6Gbps versions that they were built on. But, in order to have a full working ecosystem, you need more than just a RAID card and a stack of SSDs. You need cables, backplanes and enclosures. Considering how many 6Gbps SATA/SAS products that are on the market, those things should be easy to find, right? Not so fast.
When moving to 12Gbps SAS, cables and backplanes had to be specifically designed to support 12Gbps signaling. Simply changing the connectors on a 6Gbps backplane was not good enough. The T10 SAS 3.0 specification calls for transmit and receive equalization to maintain error free transfers, which is just one of the many changes required in the 3.0 spec. If that sounds even vaguely familiar, you probably know a little bit about PCI Express, specifically the 3.0 specification. PCIe 3.0 was the first serial protocol to implement this adaptive equalization. At a signal integrity level, SAS 3.0 and PCIe 3.0 are very similar. This helps explain why so much effort was put into the design and validation of 12Gbps SAS products, including cables and backplanes.
RAID adapters and SSDs paved the 12Gbps way, but enclosures were almost non-existent. This led us to some very awkward initial test setups that were not exactly ideal. Think stacks of SSDs with foam spacers, external power supplies and re-purposed server fans. Not our proudest moment. This is the exact reason why we were excited to get our hands on the Serial Cables SA-ENC12G-01A.
The SA-ENC12G-01A is an 8 bay, direct attached storage (DAS) product that is fully 12Gbps SAS compliant. It can also double as a 6Gbps SATA/SAS enclosure, but that is probably a secondary use case. This product fills an interesting market. While SAS 3.0 is a decidedly enterprise standard, the SA-ENC12G-01A floats between traditional enterprise IT server rooms and the desktop. It is one of the first DAS products to support 12Gbps SAS that isn’t a +20″ deep 2U rackmount solution. It’s small, compact form-factor just begs for you to set it on your desk. Serial Cables also sells an adapter kit that allows you to connect 2 of them in a storage rack with a 2U height.
With a price of $899, available directly through Serial Cables, the SA-ENC12G-01A seems like a good deal, especially when compared to larger DAS products.
Before we take a detailed look at the SA-ENC12G-01A, we have to thank HGST for providing eight SSD800MM 400GB 12Gbps SAS SSDs. As we have seen multiple times in the past, these SSDs are the best. Without their support, we could not have properly reviewed this product.
A LOOK INSIDE THE SERIAL CABLES SA-ENC12G-01A
The front of the SA-ENC12G-01A is fairly standard, with 8 drive bays, an alarm reset switch and fan failure and power LEDs. Taking a closer look at the drive carriers we see a simple design that doesn’t waste any space.
Our HGST SSD800MM fills every bit of space in the carrier. The carriers are not the most robust that we have ever seen but are on par with solutions from Chenbro and SuperMicro.
Around the back, you can see the primary fan located near the top of the unit. This Delta Electronics 80mm x 38mm fan is responsible for all of the drive air flow. This fan is rated at 5700RPM, with 80CFM of air flow and 52.5 dB-A of noise. Directly above the main fan is the power switch.
At the bottom of unit is the AC power plug and the small power supply fan. The power supply is a ZIPPY EMACS P1S-5150V, which is a high efficiency mini 1U supply. ZIPPY is a pretty well known company that is used in many enterprise and server products.
Finally, we have the external SAS connectors. The SA-ENC12G-01A provides connectors for both primary and secondary connections, labeled P1-P8 and S1-S8, respectively. This allows for data path redundancy in the case of failure.