Force10's Deep Buffer Switch

Force10's new S60 to of rack switch demonstrates that with all the buzz around 10Gb Ethernet, 1Gb still has some legs in the data center. Enterprise IT is still buying servers with 1 or more Gb NICs on the motherboard. Until 10Gb LAN on motherboards is the norm, which will drive 10Gb pricing downward, Gb will be here to stay. There isn't much that is earth-shattering about the S60, but is a welcome addition for Force10's existing customers.

The S60 has 44 10/100/1000 copper ports, four SPF Gb ports, and four 10Gb ports to uplink to the core or to stack between other S60's. Airflow is front-to-back or back-to-front, which maintains hot aisle/cold aisle containment in a small 1RU package. The airflow direction is set at the time of purchase and isn't reversible in the field.

Force10 takes a twist on buffer usage, however. The S60 supports 1.25GB of buffer for packet queuing, and the buffers are tunable, so you can tune how the buffer space is used. Tuning sounds great for networks with consistent traffic profiles, but buffer tuning would be much more valuable if it was automated. At 1.25GB of buffer per switch, the S60 can help mitigate the effects of congestion and discards by buffering traffic waiting for the congestion to get relieved. That could provide a performance boost for protocols like iSCSI that can be adversely affected by packet loss.

"The S60's deep buffers should vastly reduce packet loss. On a typical aggregation switch, the core can send data at 10Gbps to a 1Gbps endpoint so fast that packets drop on the ground. Since TCP recovers from lost packets slowly, this can have a serious impact on application performance. DCB promises to solve this problem with proper flow control, but is only on the roadmap for 10Gbps and up," says Howard Marks, founder and chief scientist of DeepStorage.net.

Force10 compares the S60 to existing switches such as the Arista 7048, Brocade FCX648, Cisco 4948, Extreme x450A, or Juniper EX4200. On a feature basis, the S60 draws low power at 156watts, which when taken in aggregate over a large number of switches, can offer a substantial savings in electrical costs. The buffer size can extend the life of 1Gb servers running native applications. Servers running hypervisors need more I/O than a single GB port can support. The price of bonding four 1Gb ports is close to a single 10Gb port, so that it makes more sense to go 10Gb. The S60 will be available June 30th starting price will be approximately $10,595.