I know, this is not brand new or hot news but I thought, you might be interested in this tool. While surfing the web I found this little 20 KB tool and it comes in handy for testing your CPU cooling effectiveness. It stressed my Athlon as much as I expected but it is really nice to test the cooling system.
These programs are designed to load x86 CPUs as heavily as possible for the purposes of system testing. They have been optimized for different processors. FPU and ALU instructions are coded an assembler endless loop. They do not test every instruction. The goal has been to maximize heat production from the CPU, putting stress on the CPU itself, cooling system, motherboard (especially voltage regulators) and power supply (likely cause of burnBX/MMX errors). Read More...

burnP5 is optimized for Intel Pentium w&w/o MMX processors
P6 is for Intel PentiumPro, PentiumII&III and Celeron CPUs
K6 is for AMD K6 processors
K7 is for AMD Athlon/Duron processors
MMX is to test cache/memory interfaces on all CPUs with MMX
BX is an alternate cache/memory test for Intel CPUs
Burn* will run endlessly _UNLESS_ an arithmetic error is detected. Check up on it with the Task Manager. It will terminate with an error code of 1 if a computational error is detected. It checks every 3-8 seconds. I haven't seen any terminations, the CPUs always lockup first. Let me know if errors happen to you. *** WARNING *** This program is designed to heavily load CPU chips. Undercooled, overclocked or otherwise weak systems may fail causing data loss (filesystem corruption) and possibly permanent damage to electronic components. Nor will it catch all flaws.
*** USE AT YOUR OWN RISK *** Download
Make sure to read the Read file first.