SpeedFan Portable is a system tool that can read the temperatures, voltages and fan speeds. It works by checking the status of your hard disk using S.M.A.R.T. or SCSI attributes in computers with hardware monitor chips. Use it to change the speed of the fans to keep your computer from overheating. The software is fully configurable and requires no installation. You can also create custom events to automatically handle just about every situation. SpeedFan requires roughly 3.76MB of free space for portable installation.
Fan Speed and Temp Control – SpeedFan Portable
Authors Website: almico.com/speedfan.php
Download: Download Speedfan
It appears that the latest version of this tool is not portable.