Tools for finding PC-performance bottlenecks-by Fred Langa

By Fred Langa

That old saying, "A chain is only as strong as its weakest link," has its Windows analogue: "A PC is only as fast as its slowest subsystem."

You can use Windows' built-in performance-monitoring tools to detect which of your PC's major subsystems could be causing slowdowns.

Ideally, a PC's four major hardware subsystems — CPU, drive, memory (RAM), and networking — work together as a seamless whole, handing tasks off from one to another without delay or difficulty.

But if one subsystem can't keep up with its workload, the entire PC can bog down while the other subsystems wait for it to catch up.

Fortunately, there's an easy way to tell whether your PC has a hardware-based bottleneck.

All versions of Windows starting with Vista include a graphical performance-monitoring tool (Win7 and Win8 actually offer two) that shows, in near-real-time, how a PC's major hardware subsystems are being affected by their workload.

These monitoring tools vary somewhat, depending on the Windows version (even the names are different), but they're all extremely simple to use for basic performance monitoring. Side-by-side graphs display each subsystem's moment-by-moment level of activity, giving you a visual representation of workload changes, even as you run tasks on the PC.

Figure 1 shows an example clipped from Win8's Task Manager. Other monitor-tool versions look somewhat different but convey the same type of information.

Figure 1. Task Manager displaying subsystem activity for a healthy Win8 PC under a light workload

If your system has a hardware bottleneck, at least one of the graphs will be seriously out of step with the others. It'll typically show a sustained, high level of activity, while other subsystems have relatively low activity levels. For example, Figure 2 shows C: drive access pegged at 100 percent.

Figure 2. A serious mismatch in subsystem activity — 100 percent C: drive utilization — might indicate a bottleneck worth investigation.

Keep in mind, however, that every instance of high activity doesn't necessarily represent a true bottleneck. Sometimes, high subsystem activity is due to totally benign causes, as I'll show in a moment.

But if the monitors show that a particular hardware subsystem is routinely or frequently maxed out during normal, everyday system operations, the subsystem is likely to be the weak link in your PC's performance chain. It's probably the cause of most system slowdowns.

Deciphering Windows' built-in performance-monitoring tools. The rest of this article will show how to access and use Windows' performance-monitoring tools. I'll explain how to interpret what the graphs reveal and what to do if you suspect you've found a bottleneck.

Although this article focuses just on troubleshooting hardware-based bottlenecks, Windows' monitoring tools also provide detailed, fine-grained information about numerous aspects of software performance. Below, you'll find links to additional information for exploring more advanced monitoring-tool uses.

Accessing Win8's dual performance monitors

Windows 8 has a pair of performance monitors; the easiest to access and use is the Performance tab built into Win8's Task Manager. It's significantly more useful and better-looking than its Windows 7 counterpart.

To access it, open Task Manager by your preferred method — Win8.1 offers several ways. For example, there's the classic Ctrl + Alt + Del method. But you can also pop up the advanced-user menu by either clicking Windows key + x or right-clicking the Start button on the Desktop. Whichever menu you get to, select Task Manager.

You can open Task Manager directly by clicking Ctrl + Shift + Esc or by right-clicking an empty space on the Taskbar and selecting Task Manager. (If Task Manager opens as a small, relatively simple window, click the More details link at the bottom.)

With Task Manager open, select the Performance tab. You'll see a window that looks something like that shown in Figure 3 (though, of course, your performance details will differ).

Figure 3. Win8's Task Manager/Performance view is the easiest and best-looking performance-graphing tool Microsoft has ever offered.

Windows 8 also offers a version of the classic Windows Resource Monitor, which provides an extensive list of highly detailed performance-monitoring functions. The Win8 Resource Monitor operates much like the Win7 version, described in the next section.

Win8's Resource Monitor is available from Task Manager — simply click the Open Resource Monitor link at the bottom of the window. You can, of course, also enter resmon into the Win8 search box and click its name when it appears. Once open, Win8's Resource Monitor will look similar to Figure 4.

Figure 4. Win8's Resource Monitor still has an old-school look, but it lets you drill deeply into system-performance information.

For more information on Win8's Performance Monitor and Resource Monitor, see:

• "A visual tour of Win8's new Task Manager" – June 12, 2014, Best Practices
• "Windows 8 Task Manager in-depth" – Microsoft Windows blog
• "The Windows 8 Task Manager" – MSDN blog
• "Performance management: Monitoring CPU resources" – TechNet blog.

Note: Microsoft offers scant help for Win8's Resource Monitor. But as mentioned earlier, the Win8 tool operates much like Win7's. See the Win7 "More information" links below for additional guidance.

Accessing Win7's performance-monitoring tools

Windows 7's Task Manager also has a Performance tab. But as noted above, it's far more limited than its Win8 counterpart. I recommend skipping directly to Win7's Resource Monitor. Either click the link at the bottom of the Performance tab in Task Manager, or click Start and enter resmon into the search box. Click resmon when it appears. (You might be prompted for admin permission.) Win7's Resource Monitor will look like what's shown in Figure 5. (It's nearly identical to the Win8 version shown in Figure 4.)

Figure 5. Like its Win8 counterpart, Win7's Resource Monitor provides a detailed look at what's going on inside Windows.

For more information on performance monitoring in Win7, see:

• "What's new in performance and reliability monitoring" – TechNet page
• "Performance monitoring getting started guide" – TechNet page
• "Resource availability troubleshooting getting started guide" – TechNet page.

Vista's Reliability and Performance Monitor

The Reliability and Performance Monitor tool is located in Vista's Management Console.

To access it, click Start, right-click Computer, and then click Manage. (Again, you might be asked for admin permission.) When the Computer Management console opens, click Reliability and Performance in the left pane (see Figure 6).

Figure 6. Vista's Reliability and Performance monitor is found within the Computer Management console.

For more information, see:

• "Windows Vista performance and reliability monitoring step-by-step guide" – TechNet page
• "Selected scenarios for monitoring performance with Windows Vista" – TechNet page

Using Windows' performance-monitoring tools

To save space, I'll refer to all of Windows' performance-monitoring tools — Win8's Task Manager–based Performance monitor, Win7's and Win8's Resource Monitor, and Vista's Reliability and Performance Monitor — by the generic name of performance monitor.

The best way to check your PC for hardware bottlenecks is to open a performance monitor and position its graphs so that they're visible — or at least easily accessible — while you go about your everyday computing tasks.

While you work, keep an eye on the performance graphs; you want to become familiar with how your PC responds to varying workloads. For example, note drive, CPU, and networking activity as you open applications, copy large and small files from one place to another, and download videos from the Web.

At times, some or all of your hardware subsystems will have relatively short bursts of maximum usage. That's completely normal; it's not necessarily a sign of trouble. In fact, it's what you want: to execute tasks as quickly as it can, a PC should bring all available resources to bear.

Some tasks will give one subsystem a long and heavy workout. For example, the Disk graph should show maximum activity when you're running a full system backup. If you're recalculating a giant spreadsheet or editing and rendering a large video file, you'd expect your CPU to be working flat-out for a while.

Such easily explained, high levels of sustained activity are generally not signs of a severe system bottleneck. On the other hand, frequent and/or long, unexplained slowdowns — especially during routine, day-to-day operations that shouldn't cause trouble — are another matter.

When your PC suddenly slows for no apparent reason, take a look at your performance graphs. If one particular subsystem is frequently registering sustained, maximum activity while the other subsystems are operating at much lower levels, it's almost assuredly the processing bottleneck.

Balancing performance across all subsystems

Obviously, it makes no sense to have a super-fast CPU and a slow hard drive or to try running memory-intensive applications such as virtual machines or video editing with just 2GB of RAM. If one subsystem is a frequent bottleneck for your computing work, you can improve performance by servicing, upgrading, or replacing that subsystem. Here are some ideas.

Disk bottlenecks: If performance monitoring indicates that a hard drive is causing frequent slowdowns, first try to correct the problem with a full round of disk maintenance and diagnostics. For how-to information, see the Jan. 16, 2014, Top Story, "Keep a healthy PC: A routine-maintenance guide"; skip down to the subsection labeled "Disk health."

If your hard drive is FAT-formatted (e.g., FAT32), consider converting it to NTFS, which is usually faster. The Windows built-in convert.exe tool can perform this conversion on the fly. See the Microsoft Windows article, "Convert a hard disk or partition to NTFS format."

Obscure drive alignment problems can also rob performance, especially on traditional, spinning-platter drives. For a discussion of drive alignment and some suggested tools (free and paid), see the Oct. 4, 2012, LangaList Plus column, "Drive alignment and solid-state drives."

If disk maintenance or software fixes don't improve things, your only real option is to upgrade to a faster hard drive.

Note: Before you shop for a new drive, measure your current drive's throughput and access speed with tools such as the Disk Throughput Tester (free; site) or HD Tune (free/paid; site). Then, when shopping for a new drive, you can focus on only those with significantly better/faster specs.

CPU bottlenecks: Visit your system vendor's website or the mainboard/chip manufacturer's site to see whether it offers diagnostic software. CPUs and mainboards are often tested as a unit. For example, Intel's Diagnostic and Performance Tools page offers links and descriptions for dozens of tools used to test CPUs and mainboards.

Other examples include the Dell diagnostic Knowledge Base webpage and HP's "Testing for hardware failures (Windows 7)" page.

If your CPU/mainboard is healthy, you're left with upgrading to a processor with more cores (info) and/or a higher clock rate (info). That might be possible, depending on the type of components and age of your system. But it's far simpler, surer, and — in the long run — usually less expensive to simply replace the entire PC with a newer, faster model — one whose components were designed to work together from the start.

Memory (RAM) bottlenecks: Check the memory subsystem's health with Microsoft's free Windows Memory Diagnostics Tool (MS Windows page). You can also try third-party tools such as the free, open-source Memtest86 (site) or Memtest86+ (site).

If your RAM is healthy, and you routinely come close to using all available memory, your best option is to add more RAM. Check your system documentation for the type and speed of memory chip the machine can use. If all memory slots are filled, you might have to replace your current memory modules with higher-capacity versions.

If your system already has all the RAM it can support, your only real option is a new mainboard or — far more simply — a new system.

Network bottlenecks: Networking problems can affect transfer speeds with network-attached storage devices and your ability to work online, but they rarely cause a general PC slowdown. Most networking issues are outside the PC — problems with cables, modems, and routers; Wi-Fi saturation; and so on. Still, for completeness, here's how to check for bottlenecks in a PC's networking subsystem.

First, run Windows' Network Diagnostics tool to see whether there's an easily correctable software or configuration problem. To do so, right-click the network icon in the Windows desktop's notification area. (If it's not visible, click the small "Show hidden icons" triangle icon in the notification area.) Select Troubleshoot problems and then let the automated repair tools do their thing.

If you prefer a more focused, manual approach, see "Network diagnostics & tracing in Windows 7" in a TechNet Magazine page. (Win8's and Vista's diagnostics are similar.)

Next, test your PC networking hardware with whatever tools the manufacturer offers. For example, Intel's "Administrative tools for Intel network adapters" page offers a collection of free diagnostic and management tools. A Realtek page offers a variety of similar tools for its networking hardware, including the simply named "Windows Diagnostic Program."

You can dig much deeper, if you wish

Although this article focuses on just one high-level task — identifying hardware bottlenecks — keep in mind that Windows' monitoring tools are actually capable of providing deeply detailed information on both hardware and software performance.

If the information in this article doesn't resolve your performance problem, use the performance-monitoring links provided above for your Windows version. In either case, you'll likely find that current versions of Windows have all the tools needed to track down exactly what's causing PC slowdowns.

Source: http://windowssecrets.com/top-story/tools-for-finding-pc-performance-bottlenecks/