Personaly I use SiSofts SANDRA Lite for all my benchmarking, hasn't let me down, ever. Its free for home use. More info about SANDRA is here. http://www.sisoftware.co.uk/index.html?dir=&location=pinformation&langx=en&a= Get it here. http://www.sisoftware.co.uk/index.html?dir=&location=downandbuy&langx=en&a= give it a try.
Want to cripple your system to really find out what it can do? Check out any program from Futuremark. Full versions you pay for, but you can run the program in demo mode to see what it will do.