Stresslinux is a minimal Linux distribution intended for testing your hardware as thoroughly as possible. It brings many of the stress testing tools together, programs like stress, cpuburn, hddtemp, bonnie, netperf, memtester, bandwidth and lm_sensors. Between them, these programs can give all parts of a computer, the CPU, memory, hard drives, network, cooling and the rest, a thorough workout and report back on their health or otherwise.
Stresslinux is useful for overclockers, system builders and for those needing to know that computers they are about to deploy are sufficiently reliable while running under high load. It is available as an ISO image or a bootable USB image. there is also a VMware virtual machine disk image and a PXE network boot file, which is useful if you have several machines to test and all can be done from one computer using PXE and remote logins.
This is a minimal distribution without a graphical interface, because that only gets in the way of some tests, so you will need some familiarity with the command line to use Stresslinux.
A good way of ensuring the reliability of your systems before you rely on them.