SiSoft Sandra is a system information and diagnostic tool that can provide all kinds of useful information about your PCs hardware.
There's comprehensive information about many system components, for instance. And we mean "comprehensive". If you double-click the Processors module, say, you won't just get the model name and speed. It'll also tell you the number of cores, processor package, core voltage rating, minimum and maximum voltage, cache details, current temperature, and a whole lot more.
The program provides a range of benchmarks to test the speed of your hard drives, removable storage, file system, mobile device file transfer, processor speed, video rendering, memory bandwidth and network performance, amongst others. These checks are particularly useful if you're trying to optimise your system with hardware or software tweaks: run the benchmark before your speedup tweak, and afterwards, and you'll see exactly how much effect it's had.
And if, say, you've just overclocked your PC, then SiSoft Sandra can also run a burn-in test to confirm that everything is stable. If it passes then your PC is probably fine. If it fails, your PC crashes or locks up, then you'll know there's a problem somewhere, and can reduce your overclock accordingly.
There's plenty of features available here, then, but if you upgrade from the free Lite version then you'll gain many more: wireless networking benchmarks, 13 hardware and 14 software information modules, amongst others. Well worth a closer look.
This is the brand new "2014" edition, with support for Windows 8.1.