Simple, Reliable Performance for iSCSI Connectivity
Optimizations for Multicore Servers
Intel Ethernet Server Adapters are designed to seamlessly scale workloads across multicore systems, whereas ofoad engine-based
HBAs are constrained by the limited headroom of the ofoad engine itself. With the current very fast rate of growth in multicore
processor performance, servers have much greater headroom to support the application over the life of the server.
Intel Ethernet Server Adapters also feature key capabilities to load-balance and distribute packet processing across multiple execution cores:
Hardware-based Native iSCSI Initiator Acceleration
Intel Ethernet Server Adapters include a number of hardware features that accelerate iSCSI trafc and improve data processing
on multicore processor-based servers. Intelligent hardware ofoads deliver iSCSI performance that exceeds the performance
demonstrated by leading iSCSI HBAs that ofoad iSCSI processing to a proprietary engine.
Intel Ethernet Server Adapters deliver specic benets for processing iSCSI trafc, as summarized in the following table:
Features Benets
Receive-side coalescing aggregates packets on incoming traffic flows to reduce processor interrupts
and direct memory access (DMA) memory copies
Reduces processor utilization
TCP segmentation offload breaks up chunks of data to be sent on the network in a hardware-based
process instead of in software
Increases throughput and lowers
processor utilization
Checksum offload receives the segmented packets from the TCP offload block and calculates
the checksum
Increases throughput and lowers
processor utilization
Direct memory access enables data copy by the chipset instead of the processor
Moves data more efficiently through
the server, improving throughput
Direct cache access allows the Ethernet controller to place data directly into processor cache, reducing
cache misses
Improves application response times
Data center bridging enables better traffic prioritization over a single interface, as well as advanced
means for shaping traffic on the network to decrease congestion.
Provides the no-drop Ethernet fabric needed
for storage traffic
Features Benets
Receive-and-transmit queues in the controllers allow network traffic streams to be distributed into
queues associated with specific processor cores
Improves processor efficiency
Receive-side scaling directs packets to different queues in the adapter without the need for reordering
and selects a processor to handle packet flow
Improves processor efficiency
Extended Message-Signaled Interrupts (MSI-X) allow multiple interrupts to be handled simultaneously
and load-balanced across multiple processor cores
Improves processor efficiency, reduces latency
Interrupt moderation reduces the number of interrupts the processor needs to handle, primarily through
adapter support for Large Send Offload and Large Receive Offload
Improves processor efficiency, reduces latency
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Simple, Reliable Performance for iSCSI Connectivity
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