Microsemi Adaptec 8E series hardware RAID adapters are an interesting new product launch. The new Adaptec 8E series of RAID controllers combined hardware RAID functionality with onboard RAM for caching. Positioned above the Adaptec 1000 series HBAs and below the 8Q and 8 series of RAID controllers.
What the Microsemi Adaptec 8E series gives you
The Microsemi Adaptec 8E series is targeted at cost optimized segments of the market that requires basic RAID 0, 1 and 10 functionality and support for SSDs. The Microsemi 8E series is positioned below the Microsemi 8 series.
One of the key areas Microsemi is addressing is SSDs. Their newer 12gbps 8 series silicon is better able to handle potential IOPS from SATA SSDs.
The other area the company is pushing is RAID 0 throughput which is higher than previous generation PCIe 2.0 based cards.
Finally, and perhaps one of the more interesting use cases is hybrid RAID where the controller can mirror SSD and HDD but perform the reads from the fast SSD rather than the slower hard drives. This is a unique feature we found interesting.
Beyond this, companies that have invested in managing Adaptec controllers can leverage the same management tools with the new 8E series. We also like the fact that these cards have a “HBA mode” which can expose disks to the OS.
What the Microsemi Adaptec 8E series does not give you
There are some major feature deletions with the Microsemi Adaptec 8E series that need to be accounted for. First, there are no RAID levels 5 and 6. Even with 8 drives attached, you cannot have hardware RAID 6 enabled. Second, there is no provision for flash-backed write cache, making the onboard RAM essentially a read cache. You can use it as a write cache but you will lose data protection in the event of a power loss. Third, you are limited to 4 or 8 devices depending on the model. The new 8E series does not support SAS expanders.
Key Takeaways from our pre-briefing with Microsemi
We did get the opportunity to speak with Microsemi before this launch. One question we posed is the need given that in a SSD system with 8x hard drives or SSDs the RAID controller makes up a relatively small part of the BOM cost. Likewise, RAID 0, 1 and 10 are very low CPU overhead RAID levels so there is marginal benefit from the offload. One of the key selling points is that this is an upgraded product compared to the Adaptec 6E series as well as the Broadcom/ Avago/ LSI SAS 9250-8i platform.
It allows for the RAID configuration independent of OS. Beyond that the company stressed the onboard RAM for caching and its Hybrid RAID technology.
We expect these cards to be in production and hitting systems in the next few weeks.
