Selecting Speedy Server NICs

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Certain built-in NIC features affect network performance significantly. Poor NIC performance hurts doubly on a server because it limits access to its services for everyone. In fact, on networks where all users share a common medium, such as Ethernet, a slow NIC on any computer on a single-cable segment decreases available bandwidth for all network users as long as that slow NIC stays busy.

When selecting a NIC for a Windows Server 2003 computer, start by identifying the network media and the connector that the card must fit. This means recognizing the type of network technology in use and deciding what type of connector the NIC must provide. After covering these basics, you have to consider numerous other NIC options to boost a card's speed and data-handling capabilities. Because server performance is critical, you improve your overall network performance by exploiting speedy NIC options.

Here's a select set of NIC options to look for in any card you want to use in a Windows Server 2003 machine (you may not be able to find a NIC that supports all of these, but try for as many as you can find and afford):

  • Bus mastering: Enables a NIC to control a computer's bus so that it can initiate and manage data transfers to and from the computer's RAM. Bus mastering allows the CPU to focus on other tasks . It offers the biggest performance boost of any of the items mentioned here and can increase network performance from 20 to 70 percent. Although bus mastering cards cost more than NICs that don't master the bus, they're essential for server use.

  • Direct Memory Access (DMA): Enables NICs to transfer data directly from on-board RAM buffers into a computer's main RAM without requiring the CPU's involvement in the data transfer. DMA can boost NIC performance by as much as 20 to 25 percent.

  • On-board coprocessors : Coprocessors are CPUs built into a NIC itself. They enable NICs to handle data without involving the CPU. Most modern NICs include coprocessors to boost network performance, so it's hard to estimate their overall contribution to performance improvements.

  • RAM buffering: Incorporates additional RAM on a NIC to provide storage space for incoming and outgoing data. Extra buffering boosts network performance because it enables a NIC to process data as fast as possible, without having to pause to empty and refill its buffers.

  • Plug-and-Play compatibility: One of the best features in Windows Server 2003, compared to earlier versions of Windows NT, is its improved support for Microsoft's Plug-and-Play architecture. In English, PnP (as it's usually abbreviated) means that you can insert a device into a PC and it will happily and correctly configure itself. Although this confers no performance advantages, we mention it here as an essential feature because it improves your performance by speeding installation incredibly. Earlier Windows servers often required contortions to get hardware devices installed and running. A PnP-compatible NIC or other device is a snap to install on Windows 2003!

  • Shared adapter memory: Causes a NIC's buffers to map directly into computer RAM addresses. This fools the computer into thinking that it's writing to its own memory when it's really accessing a NIC's buffers. In other words, the computer treats a NIC's RAM as if it were its own.

  • Shared system memory: Reverses the preceding item, and enables an on-board NIC processor to write to an area in the computer's RAM as if it were NIC buffer space. This enables a NIC to treat computer RAM as its own and may be preferable to shared adapter memory because it allows a NIC to manage memory and frees the CPU for other tasks.

As network traffic loads go up, the value of these options follows apace. When selecting a NIC for your server, purchase the fastest PnP-compatible NIC you can afford. Invest in a 32-bit, bus-mastering, PnP-compatible NIC that uses either shared adapter or shared system memory and includes added buffer space, and you won't be disappointed.

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Windows Server 2003 for Dummies
Windows Server 2003 for Dummies
ISBN: 0764516337
EAN: 2147483647
Year: 2003
Pages: 195

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