Differences Between Windows NT Workstation 4.0 and Windows NT Server 4.0

Since the first release of the Windows NT platform in 1993, Microsoft has followed a strategy of providing the same kernel architecture, user interface and Application Programming Interface (API) across both the Windows NT Workstation and Server products, while optimizing, pricing, and licensing the products for two specific segments - the interactive desktop operating system and the high performance server. Consistent with that strategy, the Windows NT 4.0 platform is available in two versions: Windows NT Server 4.0 and Windows NT Workstation 4.0.


SUMMARY OF DIFFERENCES BETWEEN WINDOWS NT SERVER 4.0 AND WINDOWS NT WORKSTATION 4.0

The table below outlines some of the technical differences between Windows NT Workstation 4.0 and Windows NT Server 4.0.

Functionality Windows NT Workstation 4.0 Windows NT Server 4.0
Pricing/Licensing $319 (maximum of 10 computers connected - includes sharing such as file & print, peer Web services - see license for details) $809 - 5 client access licenses

$1,129 - 10 client access licenses

*Additional client access licenses required for more than 10 users - see license for details

System Design Goals Keep workstation responsive to the local user with minimum memory footprint. Network performance is the priority. Use all available memory and CPU to provide fastest network file access.
Windows 95 User Interface Yes Yes
Win32 API Yes Yes
Memory Minimum 12 MB RAM Recommended 16+ MB RAM Minimum 16 MB RAM Recommended 32+ MB RAM
Hard Disk Minimum 110 MB Minimum 160 MB
Number of Processors Supported 2 32
Fault Tolerance None Mirroring, Duplexing, RAID 5
Number of Inbound Dial-in Connections 1 256
File & Print Serving Peer (limited - see license) Yes - requires Client Access Licenses
HTTP, Gopher, FTP Serving Peer (limited - see license) Yes - Internet Information Server
DNS Server No Yes
DHCP Server No Yes
WINS Server No Yes
Index Server No Yes - available free on Internet
Web Authoring No Yes - Microsoft FrontPage included
Services for Macintosh No Yes
File and Print Services for NetWare No Yes - add-on product
Directory Services Manager for NetWare No Yes - add-on product
Runs Microsoft BackOffice and BackOffice Server Logo Applications No Yes
Administrative Control Local administrative control and restricted remote administration Centralized administrative control across all desktops and servers
Performance Tuning
  • User's foreground application maintains highest priority.
  • Applications granted minimum memory at startup.
  • Scheduler uses short timeslices for maximum user response.
  • Network services retain highest system priority. File cache is preserved above all other services.
  • Applications granted maximum requested memory at startup.
  • Scheduler uses long timeslices to respond to network requests.

DETAILS ON WINDOWS NT PERFORMANCE OPTIMIZATIONS

Since its inception, Windows NT Workstation has been tuned to provide the best possible performance for a single interactive desktop user. In contrast, Windows NT Server has been tuned to provide great performance when used as a server operating system, with multiple users making simultaneous connections to the server. For example, a user who is working at their PC wants a highly-responsive desktop, with fast graphics and the ability to quickly switch between multiple tasks. However, responding to user input and graphics performance are less important on a dedicated server where sharing files, printers, and Web pages are the priority. With this release Microsoft continues to optimize performance for both server or workstation applications by eliminating scalability bottlenecks of Windows NT Server, configuring network components for minimal memory consumption on Windows NT Workstation 4.0, and tuning network caches depending on usage.

Below are key areas of the Windows NT core system that are performance-tuned for usage as a workstation or server:

  • Task Scheduling - In order to provide maximum user responsiveness, the task scheduler in Windows NT Workstation divides its time into very short timeslices, so that multiple tasks can be loaded and unloaded rapidly, without the user experiencing delays. Users can quickly switch from one task to another, and the system remains responsive. The task scheduler in Windows NT Server divides its time into longer timeslices, allowing the server to better handle network requests without interruption. This is particularly important with Symmetric Multiprocessing (SMP) applications where thread and cache synchronization is critical across each processor.
  • Memory Allocation - In Windows NT Workstation applications are granted the minimum necessary memory at load time, as workstation users typically load and unload various applications in a single session. In Windows NT Server applications are granted all memory requested (if available) at load time, as servers are typically configured with more memory than workstations and server-based applications are infrequently loaded and unloaded.
  • I/O Throughput - A critical distinction of the architecture of Windows NT Server is that access to key system resources is dynamically and equally parceled out. A small number of worker tasks or threads service the queue of incoming user requests with dynamic load balancing across CPUs and high performance access to protected virtual memory space and network I/O. Windows NT Workstation does not have the same number of dedicated resources to support a heavy file server load and funnels any incoming network requests through a single queue.
  • File Cache - In Windows NT Server, the file cache is given the highest memory priority in order to boost network performance. In Windows NT Workstation, the user's foreground process is given the highest memory priority in order to provide maximum responsiveness.

The following graphs illustrate how these optimizations affect the performance of each product.* The first graph shows that, as the number of clients connecting to each system increases, Windows NT Server 4.0 allows the percentage of CPU time taken by network file sharing to approach 100 percent, while Windows NT Workstation 4.0 keeps network CPU time low to keep the system responsive to local applications and user input.

*NOTE: This information is presented to demonstrate the effect of increased client load on Windows NT Workstation 4.0 and Windows NT Server 4.0. In production environments, Windows NT Workstation 4.0 is not licensed, tested or supported beyond 10 simultaneous inbound computers connecting to the workstation computer (see License for details).

The benefit of keeping the network CPU utilization of Windows NT Workstation 4.0 low is evident in the following graph, which shows the Winstone32 test scores for local interactive performance. As the number of clients increases, the Winstone32 score for Windows NT Workstation 4.0 stays high, indicating high performance for local applications. On Windows NT Server 4.0, because the CPU is consumed with networking operations, the Winstone32 score decreases rapidly, and times out after approximately 30 users.

By allowing the network CPU utilization to freely scale with the number of connecting clients, Windows NT Server 4.0 is able to maintain high network performance as the number of clients increases. The following graph shows that the client wait time stays low as more clients connect to Windows NT Server 4.0, while quickly increasing when connecting to Windows NT Workstation.

Summarizing these performance optimizations, Windows NT Workstation 4.0 is tuned for maximum user responsiveness and minimum memory footprint, while Windows NT Server 4.0 is tuned for faster I/O and network throughput. Windows NT Workstation will always sacrifice peer network sharing performance for user responsiveness, while Windows NT Server sacrifices fast graphic redraw and user input for file server performance.


CONCLUSION

Microsoft is committed to providing a consistent kernel architecture, user interface, and API across the Windows family of products, while at the same time tuning and optimizing each product appropriately for its primary user. The performance enhancements in Windows NT Workstation 4.0 make it a compelling high-powered, interactive desktop operating system. Likewise, the enhancements to Windows NT Server 4.0 make it the clear choice for multipurpose server usage.

The combination of Windows NT Server, and Windows NT Workstation or Windows 95 on client PCs running Microsoft Internet Explorer continue to be the best Internet/intranet value available. Microsoft is committed to continue working closely with customers to develop the best solutions possible.

Performance graphs based on WinStone and Microsoft WebCat performance tests. For more information on Windows NT Server 4.0 performance, see http://www.microsoft.com/ntserver/ntsbench.htm.

1996 Microsoft Corporation