MAINOCCT Perestro´ka is a stability checking tool, free for personal use.
It comes with 4 built-in test aimed at testing CPUs, GPUs and Power supplies. OCCT also monitors in temperatures, voltages and fan speed, as well as system constants such as CPU Usage, Memory Usage and FPS (if testing in 3d).
It provides the most accurate error-detection algorithm for CPU and GPUs.
Windows 8 Support (Reminder)
Several bugfixes to the main UI (Translation issues mostly)
Added warning about OCCT not being free in a commercial environment
Added a Memtest mode (will plow through GPU memory). Limited to 2GB for now (will be improved later)
Added Graphic card detection and selection for testing
Added supported resolution detection (you can still specify your own resolution)
Fixed a crash when the frame limiter was set to 0
Fixed a memory leak in GPU:3D
Real-time frequency monitoring for CPU, GPU,...
Improved GPU support
Merged the CPU Frequency and Memory Used graphs
Almost all translations have been updated (Russian and Japanese ones lack updating - will come soon)