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BuildOrBuy Group Network
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BuildOrBuy News -
images/bullet2.gifGigabit Ethernet Networking Solutions
Communication Streaming Architecture (CSA):

Intel's new Gigabit Ethernet communications architecture! Eliminating the Bottleneck for PCI Networking.

Gigabit Ethernet (1000BaseT) CAT5, RJ45 Copper is backwards compatible with 100BaseT and 10BaseT EtherNet Technologies. Have 100BaseT infrastructure already installed? Good! Installing Gigabit Ethernet? Sure. Plan ahead! On Intel's CSA Bus Architecture it makes sense on new PC's right now when those PC's are Intel P4's. Adding Gigabit Ethernet Adapters on a 32 bit PCI Bus architecture, maybe not. The PCI Bus can handle up to 400 Mbps throughput whereas Intel's CSA Gigabit architecture can handle throughput of 750 Mbps (Megabits per second). Big difference? Not full 1000BaseT, still better than 100BaseT Duplexed on a Switch when you know the Specs and Bus architecture limitations. Expect Gigabit Switch prices to follow suit! Linksys has an 8 Port SOHO Gigabit Switch reasonably priced and available today (7/15/2003).

IO Bus - Peripheral Bus
Trade Associations
Transfer Rate Specs
Windows Help
10 Gigabit Ethernet Alliance

CSA creates a dedicated link from the (MCH) Memory Controller Hub to the Network Interface (LOM - LAN on MotherBoard), offloading network traffic from the PCI Bus. CSA, based on HubLink Architecture, provides a bi-directional bandwidth throughput of 266 MB per second (2 Gbps) theoretically, making it twice as fast as the 32-bit PCI Bus interface.

Direct attachment to the MCH affords a double benefit - Memory read and write operations have lower latencies, because data moves directly from the Network interface to RAM. CSA also reduces the number of traverses across the HubLink interface to the ICH by half, further reducing the latency of the network transmission. Network-sourced traffic is sent from the network controller via CSA to the MCH and RAM, then to the (ICH) I/O Controller Hub via the HubLink interface and local storage. This architecture eliminates the latencies inherent to PCI-based network traffic.

In other words, CSA is a dedicated bus that connects to the Memory Controller Hub (MCH) on the Chipsets, bypassing the PCI Bus on the I/O Controller Hub, freeing its bandwidth for other I/O operations. The CSA connection provides bi-directional bandwidth of 2 Gbps, twice that of the 32-bit PCI bus. 

By creating a new communications interface that directly connects the Memory Controller Hub (MCH) on the Chipset to the network controller, Intel has created Communication Streaming Architecture (CSA). With CSA-based motherboards, network data can be transferred at a much higher rate with lower latency. This new interface performs networking tasks more efficiently, achieves bi-directional Gigabit speeds and eliminates network traffic through the PCI bus. CSA is a proprietary Bus licensed from Intel for use on MotherBoards supporting Intel chipsets.

  1. Intel Communications Streaming Architecture - Reduce PCI Bottlenecks:
  2. www.intel.com/design/network/
  3. www.intel.com/network/connectivity/go/gig_platforms/
  4. Intel Chipset - PCI - Efficient Use: Network Throughput For PCI NIC's. PCI Performance Metrics - Useful metrics for describing PCI performance include: Bus Utilization, Throughput & PCI Efficiency. PCI Throughput - The standard definition for throughput is the amount of data passed per unit time.

    "Original Equipment Manufacturers (OEMs) and System Integrators rely on Original Design Manufacturers (ODMs), to supply motherboards reflecting the needs of today's marketplace. These ODMs include the following:

    1. ABIT Computer Corporation
    2. Gigabyte Technology Co., Ltd.
    3. IWill Corporation
    4. Micro-Star Int'l Co., Ltd

    In order to deliver competitive products, ODMs look for early signals about market shifts and technology development. Several are now introducing Gigabit Ethernet as a standard feature on their high volume motherboards indicating a movement towards Gigabit Ethernet for business platforms."


  5. Intel Pro/1000 CT - www.intel.com/pressroom/archive/releases/20030317net.htm

    Integrated Intel PRO/1000 CT Desktop Connection LAN for Onboard Gigabit Ethernet LAN connectivity a.k.a. (LOM) LAN on MotherBoard.

  6. Intel 82547EI Gigabit Ethernet Controller: "Full-duplex Gigabit throughput and higher platform performance with Communication Streaming Architecture (CSA).

    The Intel 82547EI Gigabit Ethernet Controller, coupled with Intel 875 chipset, enable full-duplex Gigabit networking performance for LOM designs using CSA with enhanced management capabilities and design flexibility."

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Web Development, Gill Boyd & Team - Posted 04/17/2003; Updated 03/05/2004