LSI currently offers three series of SAS RAID controllers: Entry Line, Value Line and Feature Line. The Entry Line MegaRAID SAS 82xx series is the baseline not only in its name but also in its hardware properties. Its controllers do not have dedicated processors or buffer memory and do not support RAID6. Thus, this series is meant for people who don’t need maximum performance or high data security. The other two series offer full-fledged controllers but the Feature Line 88xx series is more functional. It comes with more memory and offers external connectors. Thus, it supports more devices connected via an expander.
But today we are going to talk about a controller from the Value Line. Its model name is 8708EM2. Like many other LSI controllers, it has a twin brother selling under the name of Intel SRCSASBB8I. You can see for yourself that these two controllers are much more than just similar-looking.
Closer Look at LSI MegaRAID SAS 8708EM2
The Value Line currently includes four controllers based on the latest generation of chips. The models differ in the number of ports (8 or 4) and form-factor: the EM2 models are shorter, MD2-compliant and have a PCI Express x8 interface whereas the ELP models are longer and use PCI Express x4.
Following the general revision of its corporate style, the company has changed the product package design. Instead of gloomy blue and black hues the box is now painted a sprightly mix of orange and white. The box may seem even gaudy but at least it is sure to catch the customer’s eye.
The controller is based on a RAID-on-chip processor LSISAS1078 that has PowerPC architecture and a clock rate of 500MHz. This is not high after we’ve seen the Adaptec ASR-5805 with its 1.2GHz dual-core chip but, on the other hand, the 3ware 9690SA-8I controller coped with RAID arrays well even at half that frequency by utilizing the advantages of its processor architecture. So, let us wait until the practical tests before we judge this controller’s speed.
As opposed to the 88xx series controllers that are equipped with 512MB or 256MB of memory, the 8708EM2 comes with only 128 megabytes of DDR2 SDRAM clocked at 667MHz.
The box contains a brief user manual, a disc with drivers, a back-panel bracket, and two cables. Each cable allows connecting up to four devices to each of the controller’s SFF-8087 connectors.
The controllers from LSI’s two senior product series support all the popular array types including:
- Single HDD
There is everything you need to build a RAID for your particular applications. The lack of RAID1E and RAID5EE, let alone even more exotic array types, should not be a problem for most users.
As usual, we run the controller with a BBU and strongly recommend you using a BBU, too. Your data and the time you can spend recovering it are far more expensive than this simple accessory.
We used an LSIiBBU06 which was fastened right to the controller’s PCB with three small poles. Take note that the other 87xx and 88xx series controllers employ other BBUs.
And finally, we’d like to say a few words about the software aspect. The manufacturer’s website offers a broad choice of drivers for various OSes. You can also download OS-specific versions of MegaCLI, the exclusive tool for managing the controller and arrays from an OS. Its functionality is broad enough for you not to have any need to enter the controller’s BIOS, but its interface is far from friendly: the context menu is too context-dependent and it is hard to understand where the menu item responsible for the particular operation is. One gets used to the menu over time, though.