Alacritech Device Is More
Than HBA"> To the untrained eye, Alacritech Inc.s Alacritech 1000x1 Single Port Server and Storage Accelerator is simply a utilitarian network HBA. However, in eWeek Labs tests, this new device demonstrated high performance and versatility that could be the key that opens up the world of IP storage to host bus adapters. The 1000x1 device, which shipped earlier this month, uses Alacritechs proprietary SLIC (Session-Layer Interface Card) technology to offload network protocol processing chores from a server. Because protocol processing is done by the devices hardware, server CPU utilization is cut significantly, even during intensive I/O operations.Simply put, the Alacritech 1000x1 makes possible IP storage networking at high speeds with low CPU utilization, which will justify the devices price in most larger enterprises. With a list price of $999 per adapter, the Alacritech 1000x1 is more expensive than most other Gigabit Ethernet adapters, which usually range from $80 to a little more than $200. The Alacritech 1000x1 is hampered by limited interoperability, however: Currently, the device runs only on Windows platforms. According to company officials, Linux support is in the works, but for this card to become a major force, Alacritech must expand the 1000x1s support to include Unix servers such as Solaris, HP-UX and AIX. Speed Tests Perhaps even more important than the offloading aspect of the card is the raw performance it can produce. We opted to test the 1000x1 HBA as a storage controller, instead of putting the device through the usual network adapter paces, to see if it has the potential to be a major player in the storage networking marketand it does, as our test results showed. We ran tests using Intel Corp.s Iometer benchmark and found the Alacritech 1000x1 HBA clocked as much as 217MB per second of throughput while running the card in full-duplex mode. To put this speed in perspective, we would expect such performance from a garden-variety 2G-bps Fibre Channel HBA. In our tests, the Alacritech 1000x1 showed the ability to handle both iSCSI traffic and IP networking traffic on the same adapter. The ability to perform both storage and networking tasks from a single slot will make the Alacritech 1000x1 desirable for rack-dense servers that have very few PCI slots. Clearly, any IT manager concerned with performance should make sure that they use a solution with offloaded TCP/IP processing in their iSCSI-based SANs (storage area networks). Although the 1000x1 HBA cannot offload iSCSI operations (a software iSCSI client is required), its TCP/IP offloading still makes a big difference in performance. We installed a Nishan Systems Inc. IPS 3000 Multiprotocol Storage Switch between the server with the Alacritech HBA and our storage systems. The Nishan switch took wire-speed Fibre Channel traffic and converted it into iSCSI IP traffic. To make sure our Fibre Channel disk JBOD (for just a bunch of disks) setup was not a bottleneck in our tests, we created a test suite with sequential traffic (doing both read and write operations). We saw best results when running requests that were 64KB in sizethis is where we saw the 217MB-per-second throughput reading at the expense of less than 10 percent of our CPU resources. In comparison, running the same test with an Intel 1000T Gigabit Ethernet adapter, we were able to push out only 142MB per second while burning up an alarming 45.34 percent of CPU resources. (We ran tests on a generic dual-Pentium III server.) Senior Analyst Henry Baltazar can be reached at firstname.lastname@example.org.
Offloading CPU tasks to the HBA allows IT managers to devote more server resources to important things such as applications. This capability will also enable IT managers to leverage their high-speed IP networks to send storage traffic.