# OCBase (OCCT) OCCT, from OCBase, is an all-in-one stability testing, stress testing, benchmarking, and monitoring tool for PCs. It has been around for more than twenty years and has passed 70 million downloads, which in this category counts for a lot: stability tools earn trust slowly, by being the thing that found the fault everything else missed. The name comes from "OverClock Checking Tool", and that is still its core job. You changed something (a memory profile, a voltage curve, an undervolt, a new part) and now you need to know whether the machine is actually stable, not just stable enough to boot and open a browser. ## What it tests - **CPU**: configurable stability tests with different instruction sets and data sets, from cache-friendly to memory-bound - **RAM**: memory testing and benchmarking, with presets. This is where most "random crash" mysteries actually live, usually an over-optimistic XMP or EXPO profile - **GPU (3D)**: adaptive 3D testing meant to replicate real gaming load rather than a synthetic worst case - **GPU (compute)**: separate compute workloads, which matters now that GPUs do AI and machine learning work rather than only graphics - **Power supply**: a combined CPU and GPU load designed to push the PSU. The site's own line is that power supplies hate this, and it is not joking - **Multiple GPUs at once**, including different brands in the same machine Around all of that: live monitoring of temperatures, clocks, voltages, and power, with configurable alerts that stop the test before something gets damaged, plus reports you can compare between runs and shareable stability certificates. ## Licensing Four tiers: Personal (free), Pro, Enterprise, and Enterprise+. The free Personal version is enough for anyone tuning their own machine, and the benchmarks are free. The paid tiers exist for people running this commercially: PC builders, repair shops, RMA departments, and industrial deployments. Windows is the primary platform, and a Linux version now exists as well, which is welcome given how much critical infrastructure runs on [[Linux]]. ## Notes from using it Test one thing at a time. The instinct is to run the "all-in-one" test and be done, but a failure then tells you almost nothing. Memory first, then CPU, then GPU, then the power test. When something fails, you know what to change. Set the alert thresholds before starting, not after. That is the difference between a test that protects your hardware and a test that damages it while you are away from the desk. Watch the run rather than trusting the verdict. An error after eight hours matters, but so does a machine that passes while sitting at 95°C. Passing a stress test and being a well-configured machine are two different results. And remember what these tools actually measure: they can prove instability, never stability. A clean twelve-hour run raises your confidence. It does not issue a guarantee. ## My take Most people build or upgrade a PC, enable the one-click memory profile in the BIOS, and then spend the next two years blaming random crashes on Windows, drivers, or a game. Two hours with OCCT would have found the real cause on day one. That is why I keep it around: not as an overclocker's toy, but as the tool that turns "my PC is weird sometimes" into a specific, fixable fault. Same reasoning as a good test suite. You are not looking for a green checkmark, you are looking for the failure while it is still cheap to find. ## References - Official website: https://www.ocbase.com/ - Download: https://www.ocbase.com/download - Documentation: https://www.ocbase.com/wiki - Benchmark database: https://www.ocbase.com/benchmark ## Related - [[FurMark]]: narrower and heavier on the GPU specifically; the two complement each other - [[Fan Control]]: OCCT provides the load, Fan Control shapes the response to it - [[HWiNFO]]: independent sensor readings to cross-check a run - [[GPU-Z]]: for identifying the graphics card involved - [[Linux]]: now a supported platform