CPUs and Cache
Will you need to upgrade your CPUs? Perhaps. If you're running a 386, you must upgrade to at least a 486, NT Server 5.0's minimum for basic servers, according to the Hardware Design Guide. Therefore, you can't upgrade a DOS or Windows 3.x legacy system that has less than a 486 processor to NT 5.0. Organizations with large numbers of older platforms can use a Windows-terminal approach rather than upgrade all users' desktops. Older systems that have 486 or Pentium CPUs and enough RAM and disk space will probably work fine under NT 5.0, as long as the machines are on Microsoft's Hardware Compatibility List (HCL--http://www.microsoft
.com/hwtest/hcl).
Intel no longer manufactures CPUs slower than the Pentium MMX, so if you upgrade, you'll have to upgrade to a Pentium MMX or better CPU. The Hardware Design Guide recommends a Pentium Pro or better, or a RISC processor (Alpha processors only--NT no longer supports MIPS or PowerPC processors). The Hardware Design Guide requires basic and enterprise servers to have at least 200MHz CPUs and requires SOHO servers to have 180MHz CPUs. NT 5.0 doesn't require symmetric multiprocessing (SMP) boxes, but it supports them. Multiprocessing systems must meet Intel's Multiprocessor Specification (MP Spec), version 1.4 or later. All SMP systems available today meet the specification, but some SMP systems from a few years ago don't. Those older systems won't perform well under NT 5.0.
Cache is another important hardware element. The Hardware Design Guide and PC98 System Design Guide specifications don't require cache for basic servers, but you need cache for NT 5.0 to run well. The more cache you have, the better your system will perform. PC98 System Design Guide-compliant machines that use cache must implement Level 2 cache as write-back, which means the cache controller responds immediately to the CPU and later writes transactions to the main memory, rather than writing out transactions before signaling the CPU. Write-back prevents the cache from slowing down the system during periods of high bus traffic. Chips with faster internal buses also improve system performance.
The PC98 System Design Guide and Hardware Design Guide specifications require that each processor on systems with Pentium Pro or better CPUs have its own Level 2 cache. This requirement underscores the importance of independent cache for each CPU. Tests in the Windows NT Magazine Lab (see "HP NetServer 5/166 LS4," May 1996) have demonstrated that computers with 1MB or 2MB off-chip independent cache modules are significantly faster than machines with 512KB shared-cache units. Most machines manufactured today have independent cache for each CPU, but some older systems use shared-cache modules. The Hardware Design Guide requires SOHO server CPUs to have 256KB of Level 2 cache and enterprise server CPUs to have 512KB of Level 2 cache.
Other Features
Many of the technologies PC98 System Design Guide and the Hardware Design Guide describe have been around for years. By including these technologies in the NT 5.0 specifications, Microsoft has added them to the list of technologies NT officially supports. (For more information about new hardware that NT 5.0 supports, including Advanced Configuration and Power Interface--ACPI, Universal Serial Bus--USB, and Intelligent Input/Output--I2O, see Nik Simpson, "Business Server Development and NT 5.0," page 117.)
When you're shopping for a new machine that will run NT 5.0, your first search criterion needs to be finding a system that doesn't have an ISA bus. Basic and enterprise servers can include ISA slots, but the primary expansion controllers for your disks, network, and video output cannot reside in them. SOHO servers must not contain ISA expansion slots. When you purchase new peripherals, look for devices with 32-bit tuned drivers and adapter cards that support bus mastering and Plug and Play (PnP). When you buy a server, look for a system that has the following features.
System bus. Your new system needs a bridged dual-bus PCI architecture. Such an architecture lets you place a system's NIC and disk controller on separate buses to achieve higher aggregate data throughput (264MB per second--MBps--or faster). In addition to the bridged dual-bus architecture, look for a system with a 64-bit, 66MHz PCI bus, even if the system also includes a 32-bit bus. Look for a server that has a motherboard with an onboard PCI-based VGA controller and the capability to hot-swap ACPI devices.
You need to look at your new system's device drivers. To be compatible with the Hardware Design Guide, drivers must meet several criteria. They must be fully 32-bit. They must store configuration settings in the Registry, rather than in .ini files. You need to be able to use Windows-based methods for installing and removing drivers from the hard disk. The drivers must let you use scripts to perform unattended device setups. They must use unique filenames and come with Help files. They must support PnP and power management I/O request packets. Drivers that are Windows Driver Model (WDM)-compliant need to be WDM mini-drivers. Finally, your drivers must not support real-mode or 16-bit protected-mode operation; they must support only 32-bit protected-mode operation. (This limitation is one reason why software can't write directly to hardware in any version of NT.)
If you're planning to buy a new server, look for a system bus feature that isn't part of either NT 5.0 specification: Intel's new 100MHz system bus. The 100MHz bus improves the architecture's ability to support the forthcoming 450MHz Pentium II CPUs and next year's 8-way Slot 2 Deschutes designs.
Network components. NT Server is a network OS (NOS), so the OS derives its power from the network standards and devices it supports. The network device interface specification (NDIS) 5.0 defines NT 5.0's variations from the NDIS 3.0 and NDIS 4.0 networking standards. NDIS 5.0's list of the networking capabilities that NT 5.0 supports includes PnP, new driver architecture, network power management, Windows hardware instrumentation, and task offload of TCP/IP checksum (error detection) and Point-to-Point Protocol (PPP) compression and encryption. NDIS 5.0 also includes broadcast media extensions for use with broadcast components such as TV cards. It includes support for asynchronous transfer mode (ATM); asymmetric digital subscriber line (ADSL); streaming media; Quality of Service (QOS--for example, guaranteed bandwidth); and intermediate driver support for features including broadcast, Virtual LANs (VLANs), and LAN emulation over media such as ATM, television, and FireWire (IEEE 1394). (For more information about NDIS 5.0, see http://www.microsoft.com/hwdev/devdes/ndis5.htm.)
The Hardware Design Guide recommends that servers have a NIC that is also an integrated hub with five or more non-ISA ports. The NIC needs to automatically detect the carrier mode (e.g., full- or half-duplex) and carrier speed (e.g., 10 megabits per secondMbpsor 100Mbps) and change the NIC configuration to match. The NIC also needs to have automatic hub, switch, or router detection; automatic transceiver type detection; the ability to communicate with drivers across a PCI bridge adapter; filtering for at least 32 simultaneous multicast addresses (for push technologies such as NetShow, Active Desktop, and Internet Explorer--IE--4.0); support for performance tuning and configuration through the Registry; BIOS boot; and Dynamic Host Configuration Protocol (DHCP) and Trivial File Transfer Protocol (TFTP) support for remote system setup. The Hardware Design Guide also outlines requirements for modems and interfaces for ATM, ADSL, and ISDN.
Prev. page
1
[2]
3
next page 
