Ascii2,
...The unlocked bios is really safe. You should install it and see what settings I have unlocked.
I have installed the unlocked BIOS. It seems to function much better than the stock BIOS. The fans may be prevented fro spinning down by disabling the option to use Smart Fan (Within PC Health category). The BIOS seems to have a very high shutdown threshold temperature (default 90 degrees Celsius, I believe) such that the CPU core temperature may not exceed the threshold if the fans are off in an ambient temperature of about [23+8/9] degrees Celsius. Wherefore the Smart Fan functionality maintains the fan at a low rate of spin and a temperature quite different but less than the threshold is achieved (around a toasty 55 degrees Celsius for a reasonable clean and non-obstructed computer). The disabling the Smart Fan option in the stock BIOS seemed to fail to allow the fans to cool the CPU to a more reasonable temperature; the unlocked BIOS, however, does have the option functioning correctly. The PC Health options in the C51GGU01 seem to be buggy (more on this below).
You can also fire up modbin6 from a command window. Choose the 611E3P04.BIN to view the stock bios or UNLOCKED.BIN to view the unlocked bios. Once you choose the bios just select Edit Setup Screen from the left Window pane. The hidden settings are shown in black. Let me no how you make out...
I tried looking at the settings in for the unlocked BIOS using MODBIN6 2.01.01 and MODBIN6 2.01.02. Something worth noting is that a "Frequency/Voltage Control" category is defined in BIOS (stock and unlocked), but not used (and also seems not to contain any settings).
Another thing worth mentioning is that the option displayed in MODBIN6 and set to "Normal", "CPU Thermal-Throttling", does not appear in BIOS setup.
My experience with the unlocked BIOS has been positive. Thank you MrG.