OCCT

OCCT is a tool for stability and stress testing of computer hardware components. It performs specific tests on the CPU, GPU, RAM, and power supplies, generating intense loads to detect errors or instabilities. The program integrates a real-time monitoring system that displays temperatures, voltages, and frequencies during the tests.

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• OCCT CPU test. This test subjects the processor to a variable and cyclic load, alternating periods of maximum activity with periods of lower load. Its design detects instabilities that might not appear under a constant and sustained load, identifying problems related to fluctuating voltage or temperature.
• Linpack CPU test. It uses the well-known Linpack benchmark to focus an extremely intense and sustained workload on the central processing unit. It evaluates stability under precision mathematical calculations, being effective at finding errors in aggressive overclocks or in the CPU's floating-point unit (FPU).
• Memory test. Executes a custom algorithm that writes, reads, and verifies data patterns in the system's RAM. Its main objective is to discover errors in memory modules (bad blocks), failures in communication between the memory controller and the modules, or instabilities caused by incorrectly adjusted timings (latencies).
• 3D test for GPU. Generates a complex and continuous three-dimensional load on the graphics processing unit using its internal rendering engine. This test evaluates the stability of the GPU core under thermal and load stress, useful for validating overclocks and verifying the system's cooling capacity.
• VRAM test for Video Memory. Focuses specifically on the graphics card's video memory (GDDR). It fills the VRAM with data and performs read/write operations to detect errors in the memory chips, which can manifest as visual artifacts, driver crashes, or blue screens related to the GPU.
• Power Supply test. Combines a maximum and simultaneous load on the CPU and GPU to create the highest possible power demand on the system. This test verifies the responsiveness and stability of the power supply unit (PSU) under consumption peaks, potentially revealing faults in voltage rails or insufficient power capacity.
• Real-time monitoring. Integrates a monitoring engine that captures and displays data from a multitude of system sensors in graphs. It presents data such as temperatures of all CPU and GPU cores, voltages, fan speeds, clock frequencies, component usage, and power consumption, facilitating the correlation between load and physical parameters.
• Thermal protection thresholds. Allows you to set maximum temperature limits for the CPU and GPU. If during any test these components reach the user-defined threshold, the program automatically stops execution to prevent damage from overheating.
• Graphical report generation. At the end of a test session, it allows exporting a complete report containing graphs of all monitored parameters during the execution period. This report serves as a diagnostic document for later analysis or for sharing results.
• Monitoring-only test. Allows activating the monitoring and graphing system without running any internal stress tests. This function is used to observe hardware behavior while running other applications or games, or to perform a passive system diagnosis.
• Automatic test mode. Runs a predefined sequence of tests (CPU, GPU, memory) consecutively without user intervention. It provides an overall system stability assessment after an extended period of combined tests.
• Error detection system. Continuously analyzes data during tests for inconsistencies, such as calculation errors (WHEA), hardware failures reported by sensors, or system hangs. Any detected error is logged and presented to the user as an indicator of instability.

OCCT was created and is developed by a French programmer under the alias Ocb1953. Active development of the tool began around the year 2003. Originally conceived as a utility for overclockers, its name is an acronym for OverClock Checking Tool. The program is primarily written in the C++ programming language, which contributes to its performance and low-level control over the hardware.

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