The risk of pure bricking are very low. You may, at worst, be forced to do a hard reset of the motherboard BIOS CMOS.
To verify your unlocked system, you should run Prime95 and other system verification tools.
Unlocking is not overclocking, but some parallels exist. OC generally causes higher CPU temperatures. Once unlocked, your processor has a higher TDP (peak thermal output). That means your stock cooler MAY or MAY NOT be adequate. It depends one what AMD shipped with your processor. If you can compare your cooler to someone who has a 125W (or even 140W) TDP AMD processor, you may be able to verify that you have enough cooling.
Upgrading to an aftermarket cooler has several benefits.
- One, you can direct all output
airflow towards a case output fan.
The majority of stock coolers direct
airflow in two directions. This usually causes hot air sent in one of those directions to be recirculated.
- Two, you
can reduce idle temperatures, which
may increase the total lifetime of
your processor.
- Three, you can reduce
peak temperatures, which may increase
the immediate lifetime of your
processor.
- Four, it gives you a chance to use a high-tech thermal compound, which further lowers temperatures.
- Five, they look cool.
Underclocking is usually a way to allow undervolting, which allows for lower temperatures and lower power consumption. Since unlocking a core is usually all about performance, I'm not sure what the point would be. Just get a bigger aftermarket cooler.
Since we are on the subject of heat and performance, please tell us about your total case cooling. Do you have as many cubic feet per minute (CFM) of air coming in through input fans as you do output fans? Is it a case that all air output goes through the power supply?
