hey i have a Lenovo Thinkpad Laptop with Ubuntu 12.04 installed. It runs slow. I tried "System profiler and Benchmark" to test the computer. but the application quits and closes after the first few benchmark test. before it even gets to the other tests. So i tried "Hardinfo" that installed on the Puppy Linux live cd. that did the same thing (the apps look just a like). the memory usage isnt the problem on this pc. its the cpu processes. just running the "system profiler" app that comes with ubuntu uses about 34% on each core, default with nothing running its 5-10% on each core. i cant really find what the deal is other than that ubuntu is a cpu hog. so im testing unity2D at the moment to see how it goes. if you have any other suggestions, feel free to answer this question. thanks
Lubuntu would be a better alternative.
Honestly, I would go for a very specific install with a tiny distro, or probably ubuntu minimal disc to avoid any unnecessary packaged that would make the life hard for you hardware; consider using a window & file manager double instead of a full desktop enviroment.