I am having some issues overclocking my AMD Athlon II X2 50 @3.00GHZ. I've read that people are able to get speeds of over 3.5GHZ out of it and I would like to know how. I read a few threads and tried upping the FSB a little but it doesn't let me. Once I save and restart my PC goes into safe mode.
I had an Athlon II X2 240 Stock 2.8 Overclocked to 3.5 Stable. I had a MSI 990FXA-GD65 with a bad board that I had no control over adjusting the vcore, but I could still overclock it. Core was locked, and all I had to do was adjust the FSB from 200 to 250.
(My old board VCore was so bad I couldn't use my new FX-8350 at stock settings (4.2 turbo would error with prime 95)
I don't know all of your hardware or its age, but the PSU recomended is a ballpark 350+ watts. You may want to go through the calculator to check how much you really should be using. You did not post your cooler so that's an unknown factor right there on how is it handling the thermal temps. The board is also a AM2+/AM2, your also bottle necked by using DDR2, having a lower HT than an AM3+/AM3 boards.
Frankly with the age of your board, age of the processor, weak psu and other limitations, it's time to move on like I did. Your CPU, Board, Ram and PSU, dump it and replace them. Everything else in your case is reuseable. If you were using a stock heatsink, upgrade that as well.
Time to look at Intel Ivy/Sandy Bridge, or AMD FX Vishera/Phenom II (do not get FX Zambezi); and switch to a DD3 AMD and better ram. That is the best advice I can give you.
Edit: If you really insist on overclocking it, you can try to see if you can incrementally increase the voltage on the vcore, but I question if your PSU can handle that. Once you start upgrading one thing, you might as well upgrade everything
Edit: BTW if you were on a budget and can't do a complete overhaul, you can try what I did and upgrade it intermittently in 3 stages if you stick with AMD.
1st Stage PSU
2nd Stage Mobo & Ram (AM3+/AM3 Board can still use your CPU but you need DDR3)
3rd Stage CPU (and cooler if you only have stock)
If you went Intel you would upgrade Mobo, Ram and CPU by 2nd Stage.
I'm not in the UK, so I won't be able to give you full advice on what to buy, other UK forum goers may be able to help further there.
Still, my best advice, don't go with those pre-built systems. £464.52 is about $737.75 US according to google.
So in comparison with the US market prices http://pcpartpicker.com/p/nZDl
$502.62 is about £316.47
Significant savings if your willing to build it, and over clock it yourself. You can potentially shave off costs by gutting and reusing parts of your old system in a new system. Anything you can save would be better spent elsewhere.
You also have greater quality control over what goes into the system. I notice that 600 watt psu they advertise has no brand name listed. A junk brand would cost half as much as a quality psu, and would likely fry your computer should it fail.
You still have a good video card so really skip on board graphics and go for a dedicated amd processor like the fx series. If you need better graphics you can budget it down the road depending on your use.
Anyway I digress, go read the sticky on how to ask and be as much detailed as possible