How To Stress Test Your Hardware and Keep Your PC Stable

We've shown you how to build many a PC, and chances are, you might have even attempted to build your own. Or perhaps you're looking to give your old machine a bit of an upgrade, and swap out a couple of parts. Either way, your job isn't done when you close up the case; just because a piece of hardware appears to work at first glance, doesn't mean deeper problems can't be lurking underneath.

When things go wrong with your PC, it's often hard to pinpoint where the problem lies. Crashes may become common place, or obscure errors could appear with increasing frequency. While software may easily be the culprit, a hardware problem is also just as likely — especially when dealing with a new system build or overclocked setup. 

The goal with any PC is to have a perfectly stable environment — one free of hardware-induced crashes or freezing — and the internet is rife with applications to help you do just that. Read on as we show you how to stress test your hardware to its breaking point, ensuring your PC experience is near bulletproof and problem-free.

Each of the apps we recommend here is best used over long periods of time — a span of hours, or even overnight. Testing your graphics card or CPU for just a few short minutes won't cut it, especially when diagnosing an obscure or load-related issue. Instead of cutting corners, put aside an afternoon or evening and solve your problems the right way. Or better yet, run these overnight!

To start, you'll need to download a utility like HWMonitor, which allows you to accurately measure the core and external temperature sensors for all of your PC components. Combined with SpeedFan, or a similar application, you'll have a great set of monitoring software to keep an eye on things like temperature and fan speed — important when trying to determine the stability of a system, especially if you suspect something's gone wrong.

Number Crunching And You: Stressing Your CPU

 Unlike other components within your PC, CPU problems aren't always so easy to identify. While checking your email might work without issue, resource-heavy tasks might bring your system to a halt. A stable CPU should have the ability to make reliable mathematical calculations without error, and without crashing your machine.

The standard for this sort of thing is a torture test called Prime95. The application was originally written for researchers, with the goal of combining computing power to discover new prime numbers. However, it was soon realized that the program taxed both CPU and RAM in such a way that it made a very effective testing tool. And that's exactly what we're going to do.

Prime95 offers three primary testing options, placing varying levels of stress on different components of your machine. Small FFT does basic RAM testing, but lots of CPU stress. In-place Large FFT increases the scope of RAM testing, but pushing your CPU for maximum heat and power consumption. Finally, for a mix of both, Blend combines comprehensive RAM and CPU testing at the same time. In most cases, In-place Large FFT will be your best bet, especially if run overnight. If your system succeeds without error, CPU instability is likely not an issue.

Best of all, unlike previous versions, Prime95 now supports testing across all cores. However, be sure to enable "Round off checking" from the Advanced menu. Otherwise, calculation errors won't be reported, and a BSOD or crash will be the only way to know a problem has occurred.  

Another great option is the more recent IntelBurnTest application. Based on Intel's own CPU testing utility Linpack, this tool promises to stress the CPU, Northbridge and other PC components to their absolute max — and very quickly too. Just keep in mind, this is an Intel-only tool, leaving you AMD users to stick with Prime95, or alternatives like OCCT.

And of course, be careful; while Prime95 does a great job at stressing CPU logic, IntelBurnTest will cause your CPU to heat up very quickly, perhaps to a dangerous degree with inadequate cooling. In fact, one of our MacBook Pros hit 100 °C within a minute of testing. Laptop users, you've been warned. 

RAMember To Test Your Memory (Sorry)

RAM is another component that's hard to diagnose if troubles arise, but luckily, there's only one program you'll need to identify any serious issue. Memtest86+ is the current king of memory diagnosis, and an updated version of the original Memtest86 project. Numerous tests handle everything from random writes to moving data in an attempt to find even the most obscure of RAM-based faults.

For best results, you'll want to run Memtest86+ off a USB stick, CD-ROM, or even a floppy disk if you're feeling nostalgic. While it is possible to run certain Memtest86+ builds from within Windows or Linux, OS components loaded in RAM can produce unreliable or inaccurate results.
     A total of nine tests are available for use, and increase in scope the farther down the list you go. Lower level tests are good for picking up obvious problems — useful if you've just built a new PC, or you're planning on testing a new stick of RAM. However, for less obvious issues — a level 5 test, for example, provides a good balance between execution time and error detection.

For an accurate diagnosis, it's recommended you let Memtest86+ make at least one pass through the first couple of tests — "sufficient to catch all but the most obscure errors" say the original developers. However, for more comprehensive results, it's a good idea to let multiple passes run overnight, and hope the application is still running by morning. 
 

Games, Glitches and Graphics: Stressing Your GPU

Compared to other PC components, graphical issues are often easier to identify because of their visual nature — usually seen in the form of pixelated garbage or oddly-colored textures. Some will cry foul that we don't mention 3DMark's suite of apps here, but remember, we're stress testing, and not benchmarking. The goal here is to push the GPU to its limits — a necessary task when dealing with a suspected card problems or an overclock gone wrong.

FurMark is a great application that replaces the once popular ATITool. As the name implies, FurMark stresses your system's graphics card by rendering incredibly detailed fur on a moving object in real time. Things like anti-aliasing, resolution and other settings can all be modified to max-out your graphics card's capabilities, allowing you to identify potential glitches or cooling and temperature issues.

Another good utility is the DirectX-based tool rthdrbil. Unlike FurMark, this app pushes your graphics card by rendering complex HDR lighting and reflections in real-time, thanks to an array of fast-moving spheres. It's one of the more impressive graphic renderers to watch, and multiple instances should be more than enough to bring a system to its knees.

Finally, there's often no better method for testing real-world performance than with some actual games. The S.T.A.L.K.E.R series, for example, is notorious for its demanding game engine, and offers a benchmarking tool for free on its website that you can also use to help evaluate potential problems. Other recent games, like Just Cause 2, also offer PC demoes than can be used to tax a system, and provide a better indication of real-world stability than a spinning donut of fur. FurMark and rthdrbil should still be used as your primary testing apps, but demanding game benchmarks are a good final step before certifying your system stable and problem free.

And if you do find a problem with any of your PC's components? Contact the manufacturer. Some hardware stores will accept returns on a newly purchased CPU or graphics card, as long as the product's problem can be verified. The manufacturer itself will often have RMA programs, which allow you to return the problem part for another model or repair too.

Of course, these are just a few of the most popular applications used to stress and test our systems and builds. What we're most curious to know is, what do you use? Do your programs of choice match ours, or do you have some better suggestions for PC build and overclock newbies?