Beyond the support for an entirely new platform, the watchwords for hardware support in Windows Server 2003 are sustainability and recoverability:
A new database has been introduced in Windows Server 2003 that acts as a "bad-boy" list of drivers that are known to cause problems. If you attempt to install a device using one of these drivers, the system prompts you with a warning and refuses to do the installation. The list is kept current via Windows Update. For details, see www.microsoft.com/hwdev/driver/drvprotect.htm.
This feature was first introduced in Windows 2000 and has been improved in Windows Server 2003. You can choose to automatically download digitally signed updates from Microsoft or you can download them manually to a central server for evaluation and testing prior to internal deployment. The Software Update Service (SUS) from Microsoft automates the download of updates to a central server where they can be deployed after testing.
If you upgrade a device driver and the server becomes unstable, you can use Driver Rollback to return to the old driver. This is an improvement over the Last Known Good Configuration gambit, which restores the pre-existing Registry entries but not the drivers themselves.
Larger Registry size.
The Registry size in Windows Server 2003 is limited only by the available space on the operating system volume. Previous versions of Windows, including Windows 2000, imposed a Registry size limit (RSL) of about 80 percent of paged pool memory. This change significantly improves the scalability of terminal servers, where each concurrent user has a copy of the user profile loaded in memory.
New Registry structure.
Related portions of the Registry (called cells) are now kept closer together, with better support for large cells. This improves seek and load times.
Changes to the kernel and kernel-mode debugging tools have improved the ability of developers to tighten their code. We, as system administrators, benefit because we can use the same tools for troubleshooting.
Improved memory usage.
Changes to the way paged pool memory is allocated in Windows Server 2003 greatly conserves memory and makes it possible to handle very large files during backups. Also, the system now allocates identical 4K memory pages by assignment rather than by copying, which prevents applications such as web services from using lots of memory doling out the same information to different users. The total number of contiguous memory pages has been doubled to improve support for terminal servers and applications that require large datasets.
Large driver support.
The amount of memory available to a driver has been increased from about 200K in Windows 2000 to 1GB in Windows Server 2003. This improvement is especially good news for video adapter manufacturers.
Hot memory addition.
High-availability servers such as Stratus ftServers and the new IBM Summit technology servers give administrators the ability to add memory while a machine is running. Windows Server 2003 supports this feature by dynamically resizing memory when the new RAM is added. This does not work in reverse, however. If memory must be removed for swapping, the server must be shut down.
Improved multiprocessor support.
Classic Symmetric Multiprocessor (SMP) servers share their processors on a single bus, which creates bottlenecks. Newer servers use a cache-coherent Non-Uniform Memory Allocation (ccNUMA) scheme for sharing processors. In ccNUMA, processors are married to RAM that is physically situated nearby. These sections of closely allied CPU and RAM connect to each other via a series of crossbars in much the same way that cities in southern California are connected together by freeways. Windows Server 2003 supports ccNUMA architecture by allocating memory calls between "near" memory and "far" memory so that threads and memory stay in the same location.
Improved DMA handling.
If you have advanced ATA drives that take advantage of the fast transfer speeds provided by UltraDMA (Direct Memory Access), you'll be happy to know that Windows Server 2003 does a much better job of determining the correct DMA mode for a device than earlier Windows operating systems. Also, Windows Server 2003 dynamically evaluates the DMA performance of a device and shifts it to PIO (Programmed I/O) operating if it fails DMA too often. This helps maintain support for older CD-ROM devices.
Improved Device Removal handling.
Although it is not common to yank components off a running server, you may have servers with removable drives or Universal Serial Bus (USB) peripherals. The proper way to remove a device is to inform the operating system first, but surprise removals are more the rule than the exception. Windows Server 2003 prepares for the surprise removal of drives and drive media by disabling write caching on all removable media drives except IEEE 1394 FireWire.