cpu speed graph for Dell/Alienware laptops

Back in the day (until 2007) there was a program called i8kfangui that was super handy, developed independently, that would keep track of your computer's temperatures, fan speeds, and CPU load/speed, and display a rolling graph of it that you could observe at any time.

That program is no longer being developed and I'm curious if you know of any replacements. I've tried HWMonitor and SpeedFan, but neither of them show historical CPU clock speed, which for me is the most important figure.

Basically I want to know when the computer forced the CPU to drop its clock speed due to excessive temperature (i.e. when CPU+GPU are maxed out). This helps me know when I need to clean the fan. I can't look at the monitor while the CPU+GPU are maxed out, I can only go back and look at it a few minutes later.

Any other suggestions?