CPU Stability Test allows you to stretch the CPU and check whether you can overclock. It supports a multiprocessor.
CPU Stability Test allows you to torture test your computer's Central Processing Unit (CPU) and find out if it is overclocked. CPU Stability Test tests: CPU, Harddisks, RAM, caches and many sections of your Motherboard. it will test your CPU, caching subsystems, and HDs. Also supports SMP (many CPUs).

The program supports multi-processor systems, features automated crash handling and counting, includes stability rating, and lets you disable the screen saver.

Features:
1. Multi threaded
2. Supports multi-processor systems
3. Error (and CRC) checking
4. Supports MMX

The license of this software is Freeware, you can free download and free use this cpu benchmark software.