Set Sail For Uncharted NT Performance

I guess you can say that I've always questioned authority. When I hear, "Don't do that," my usual response is, "Why? What would happen if I did ?" Although my questioning nature sometimes frustrated my teachers (and perhaps contributed to a few gray hairs), such rebelliousness has its virtues. Questioning authority--in this case, Microsoft--has helped me discover new levels of system performance for Windows NT.

Mutiny on the MS Bounty
I never heeded Microsoft's decree that NT is a completely self-optimizing operating system, one that users don't need to tweak to achieve maximum performance. "Just add more expensive hardware," said Microsoft, "and the promised land of faster performance will be yours." Bah! I knew there must be ways to improve NT's performance with my existing equipment. Remembering the significant performance increases I achieved by tweaking other Microsoft operating systems, I doubted that Microsoft's developers made NT so different that they removed every possibility for the user to enhance performance. I realized that I could no longer be a mild-mannered, obedient NT user; this job clearly required a Registry pirate. With this mindset, I donned my eye patch and sword (and Registry editor), and set sail for uncharted NT performance. In this article (and in future articles), I'll log the results of my expeditions.

Pirate's Rule #1:
Default Settings Equal Milquetoast Performance
The first thing any good NT performance pirate needs to know is that default settings are usually not ideal. The good news about default settings is that they work for most users. The bad news is that they don't give everyone the best performance for a particular situation or application. After all, how can a system be truly self-optimizing if it doesn't know how you're using it? Are your applications disk bound, compute bound, or both? Does the amount of physical RAM you have far exceed your typical working set (the amount of memory a process uses or allocates), or are you running close to the edge? Do you want the highest priority to go to foreground or background tasks, or do you want execution spread evenly among all tasks? The answers to these questions significantly affect NT's performance. Furthermore, if you haven't explicitly told NT how you want the system conFigured, NT is automatically answering these questions for you. If you're like me, you'll want more involvement in the decision-making process.

Pirate's Rule #2:
The Best Buried Treasure Is in the Registry
Several Registry modifications play an important role in optimizing NT. After you understand these buried gems, you can significantly alter your system's performance. Some changes can substantially boost your system's overall speed, but inappropriate changes can decrease performance. Therefore, as I discuss each Registry modification, I'll provide enough information to help you make intelligent decisions about each change and determine which changes are appropriate for your situation. You need to be proficient in using NT's Registry editors (REGEDT32.EXE and REGEDIT.EXE) and always be prepared for disaster, which leads us to Pirate's Rule #3.

Pirate's Rule #3:
Smart Pirates Make Backups
Any modification to the system Registry, no matter how well documented or well intentioned, always involves a certain degree of risk. Any of the Registry modifications I discuss in this article can potentially damage your NT installation or make it unbootable. Therefore, you need a full system backup and an updated copy of the Emergency Repair Disk (use RDISK /S so that you get the SAM and SECURITY Registry hives in addition to the usual information that the RDISK utility backs up) before you make any changes to the Registry. I recommend that you make an additional copy of the Registry using the REGBACK.EXE utility from the Microsoft Windows NT Workstation Resource Kit or Microsoft Windows NT Server Resource Kit CD-ROMs. If your boot partition is a FAT volume accessible via an MS-DOS boot disk and the Registry becomes corrupt or damaged, you can replace the damaged version in the %SYSTEMROOT%\SYSTEM32\CONFIG folder with the uncompressed copy.

You can also restore a damaged Registry by using the option to "Press spacebar now to invoke Hardware Profile/Last Known Good menu" during NT's boot process, or by using NT Setup's option to "Repair a damaged Windows NT installation" (which uses the information stored on the Emergency Repair Disk to restore the system Registry). However, the ultimate method of performing Registry backups and restores is to use a utility designed specifically for that purpose, such as the ConfigSafe NT utility from imagine LAN. This handy utility lets you make multiple backups of your system Registry and dynamically restore your choice of versions if a problem occurs. One final utility toolkit to consider is the set of NT tools available at the NT Internals Web site (http://www.ntinternals.com and http://www.winternals.com). The NTRecover utility is handy for doing dead-system recovery when your system won't boot at all; another handy utility is NTFrob, which gives you an amazing level of control over just about every aspect of NT's file cache.

Pirate's Rule #4:
The Proof Is in the Benchmark
One final rule to keep in mind: Do not conclude that a change is effective or worthwhile until you've proved it with a benchmark. To determine the effect of a particular change, use a benchmarking utility to gain both before and after pictures of system performance. Also, remember to make only one change at a time; then, reboot the system and test. Otherwise, you won't be able to pinpoint the source of a performance improvement or degradation. I recommend two complementary benchmarking utilities that serve different purposes. U Software's Bench32 is a very effective NT and Windows 95 utility that measures CPU, memory, disk, and video performance and compares them to a baseline system. BAPCo's SYSmark for Windows NT 4.0 is a real-world application benchmark utility. Rather than measuring raw throughput for I/O subsystems, this utility measures the performance of several business applications, such as Microsoft's Word, Excel, and PowerPoint. (For more information about these two benchmark utilities, visit the U Software and BAPCo Web sites.)

First Stop: The Paging File
Let's begin our voyage by examining one of the most important contributing factors to an NT system's overall performance: the disk subsystem. NT heavily uses the paging file to swap program code and data from memory to disk and back. NT's use of the paging file is significant even on systems with large amounts of installed memory. Don't fall into the trap of believing that just because your system has lots of available RAM, the paging file goes unused. It doesn't. Although use of the paging file will certainly decrease, NT will continue to use the paging file to swap system code, user code, and data between memory and disk. Therefore, how well NT performs paging on a system is extremely important. Even systems with fast CPUs and lots of memory will suffer from a non-optimized paging file.