Solution
According to AMD a good quality 450 watt power supply is sufficient for an overclocked pc equipped with a single Radeon HD 5750 graphics card:

http://www.johnnylucky.org/graphic-cards/gpu-power-requirements.html

Both AMD and nVIdia are conservative with their recommendations. Both companies overestimate total pc power requirements because there is a tendency among consumers to purchase very cheap, low quality psu's of questionable performance and reliability.

I am not familiar with the Dany 450W. I checked Google. The Dany450W appears to be a local or regional brand. There were search results for vendors in Karachi.

Normally I recommend Seasonic, Corsair, XFX, and sometimes Antec. However, they are not available in all countries...
According to AMD a good quality 450 watt power supply is sufficient for an overclocked pc equipped with a single Radeon HD 5750 graphics card:

http://www.johnnylucky.org/graphic-cards/gpu-power-requirements.html

Both AMD and nVIdia are conservative with their recommendations. Both companies overestimate total pc power requirements because there is a tendency among consumers to purchase very cheap, low quality psu's of questionable performance and reliability.

I am not familiar with the Dany 450W. I checked Google. The Dany450W appears to be a local or regional brand. There were search results for vendors in Karachi.

Normally I recommend Seasonic, Corsair, XFX, and sometimes Antec. However, they are not available in all countries. Which psu's are available in your country?

 
Solution
Link your vender if possible; that would make it easier to recommend a brand of ps. Overclocking the processor depends on alot of factors, including the quality of the power supply and luck of the draw. The motherboard bios settings are also important.