What computer do you have?
I have a Thinkpad R61 and I can say, If i push my computer to the limit, it gets too hot. There is actually a bug in the thinkpad_acpi driver. It is well documented in Launchpad
you can run these commands and see what happens
$ cat /proc/acpi/ibm/fan
You should see that it is has similar settings as:
This seems to keep my computer at around 70 Degrees for the GPU and 60 Degrees for the CPU. But 3000 rpm is definitly not the max speed my fan can go.
To manually set your fan to max speed. Run the following code as root
$ sudo -i
# rmmod thinkpad_acpi
# modprobe thinkpad_acpi fan_control=1
# echo level disengaged | tee /proc/acpi/ibm/fan
The first line gives you super user privileged allowing you to tinker with the inner workings of your system.
The next two lines reload the driver allowing you to manually control the fan (this is dangerous as you can actually turn your fan off).
The last line lets the fan go in free running mode.
After the fan rampup (~30s), you should hear your computer doing lots of noise. This is normal, this is just your fan actually working. Mine goes at around 5500 rpm (see almost twice the speed.....).
To set the fan back to auto
$ echo level auto | tee /proc/acpi/ibm/fan
I hope this helps.