By Dave Simpson
Silverback Systems, known primarily as a chip vendor, recently entered the nascent market for iSCSI host bus adapters (HBAs). The company will compete with existing iSCSI accelerator board vendors such as Adaptec, Alacritech, Intel, and QLogic.
As do other iSCSI HBAs, Silverback’s iSNAP 2110 adapter accelerates both the iSCSI and TCP protocols. According to Harry Petty, VP of marketing, Silverback hopes to differentiate itself from its larger competitors primarily via performance and price. The company claims performance of up to 440MBps in TCP throughput and 250,000 iSCSI I/Os per second. The suggested price for the adapter through the company’s channel partners is $350.
Another differentiator, claims Petty, is that the iSNAP 2110’s architecture and firmware is scalable to 10Gbps Ethernet. The company plans to sample a 10Gbps accelerator in the first half of next year.
However, Silverback’s performance claims give rise to the question of whether iSCSI users really need the speed. According to surveys conducted by InfoStor and third-party research firms, the vast majority (more than 90%) of iSCSI deployments use free iSCSI software initiators-mostly from Microsoft-instead of hardware accelerators, which provide adequate performance in workgroup-type applications.
Analysts say that most users won’t need more speed than is provided by software initiators until they scale their iSCSI-based IP SANs well beyond most current implementations and/or make the move to 10Gbps Ethernet. Petty says that Silverback officials acknowledge that “today [they’re] addressing a niche, but the real growth will occur at 10Gbps.”
In addition to iSCSI and TCP, the iSNAP 2110 accelerates link layer traffic. Other features include a reduction in host loading via on-board Direct Data Placement, CRC acceleration, VLAN support with priority queuing, and jumbo frame processing. In Q1 2006, Silverback plans to add functionality like firmware-based RDMA, IPSec security, and a 4-port implementation. The HBA is certified with Microsoft Windows Server 2003, Red Hat Enterprise Linux 4.0, and SuSE Linux Professional 9.0 PCI-bus platforms.
AT A GLANCE
- >250,000 I/Os per second
- Scalable to 10Gbps Ethernet
- Two ports
- Single chip
- PCI bus
- Full TCP/IP and iSCSI offload with CRC
- VLAN tagging (802.1Q)
- Link aggregation (802.3AD)