Short answer - Maybe
Longer answer - So long as your motherboard has overclocking options available in the BIOS (and from Gigabyte's website, it looks like yours does), you should be able to overclock. How far depends on several factors:
■ Cooling - Overclocking will cause your CPU to produce more heat. You will need a decent cooling solution if you don't want it to overheat.
■ Voltage - Increasing the voltage fed to the CPU can stabilise overclocks, but also produces more heat (see point 1), and excessive voltage can shortens the life of the CPU, cause it to degrade, or outright die. Look up AMD's maximum voltage for your CPU (at a guess I'd imagine for a 65nm Phenom it'd be around 1.55V), and make sure not to exceed that
■ Silicon Lottery - Not all CPUs overclock equally. Due to the manufacturing process some are able to hit higher overclocks than others. this is the main reason why overclocking is not an exact science - if 4 people have CPU A, person 1 might be able to reach 3GHZ at 1.45V, person 2 might need 1.50V, person 3 might be able to do it at 1.40V and person 3 might not be able to reach 3GHz at all, his CPU might max out at 2.7GHz no matter the voltage. Since it's essentially random how good an overclocker your chip will be, it's often referred to as the silicon lottery
■ Motherboard - Since your CPU is not a Black Edition, it has a locked CPU multiplier. This means you will need to overclock using the FSB/Base clock (I believe Gigabyte call it the CPU Host Frequency. CPU speed is determined using the formula:
Code:
Core Speed = FSB speed x clock multiplier
In your case, the Phenom 9650 runs on a 200MHz FSB, and has an 11.5x multiplier. Since you can't increase the multiplier, you will need to increase the FSB speed. Again, how far this will go depends on the motherboard, for the same reasons as specified for the CPU above (increasing the FSB speed is essentially just overclocking the motherboard chipset). Check the motherboards manual for how to actually alter the FSB speed
If you're new to overclocking, I suggest you read some of the guides floating around on websites such as this one, and remember rule #0 of overclocking:
Don't overclock anything you absolutely can't afford to lose
Hope that helped, and good luck!