PC stress test and temperatures: Checking stability

In short: With stress tests and temperature display you find out whether a PC runs stably under load, cools sufficiently and whether overclocking or new hardware causes problems.

In more detail: Crashes, blue screens, restarts or performance drops often arise from overheating, unstable memory or too little power supply capacity. A stress test loads the components deliberately and reveals such errors.

In Depth

Tools

• Watching temperatures and clock: HWiNFO, HWMonitor, Core Temp, MSI Afterburner (overlay in games); on Linux sensors, htop.
• CPU test: Prime95 (very hard), Cinebench (performance and temperature), OCCT, AIDA64, stress-ng (Linux).
• GPU test: FurMark (very high, careful), 3DMark, Unigine Heaven/Superposition.
• RAM test: MemTest86 (from USB), Windows Memory Diagnostic, memtester.
• Drives: CrystalDiskInfo (SMART), CrystalDiskMark.
• Games and real applications are the most realistic test.

Which temperatures are fine?

Rough guide values under load: CPU up to about 85 °C acceptable (manufacturers state maximum values, about 95 to 100 °C, at which it throttles, thermal throttling), GPU up to about 80 to 85 °C, SSD under 70 °C. At idle 30 to 50 °C. Permanently near the limits shortens lifetime and reduces performance. Laptops reach higher values than desktop PCs.

If it gets too hot

1. Remove dust (fans, heatsinks), give the case fresh airflow.
2. Mount the cooler properly, renew thermal paste.
3. Adjust fan curves in the BIOS.
4. Undervolting lowers temperature and consumption.
5. On laptops pad, stand, cleaning.
6. With overclocking dial back.

Procedure and caution

First check the system state (drivers, BIOS, updates, thermal paste). Test step by step (10 to 30 minutes, then longer), watch temperatures and abort if they exceed limits. Errors and restarts during the test point to hardware problems (RAM, power supply, overclocking, cooling). Extreme tests such as FurMark can overload hardware; use them only briefly and monitored. Back up data beforehand.

See also: Cooling and thermal paste, Undervolting, Overclocking, Drive and SSD health