Help deciding between PSUs

[solvectro]

Hi guys
I was originally planning on getting a HD7750 but my current cheap PSU only has 18amps (probably less) on its +12v rail while the required amount is 16amps. Being a cheap PSU do you guys think it'll be able to handle the 7750 during extended periods of gaming?

If not I was thinking of getting one of these:

Antec VP-450P 450W Dual +12v rails - 18Amp
http://pricespy.co.nz/product.php?p=904886

Silverstone Strider Essential ST40F-ES 400W Single +12v rail - 25Amp
http://pricespy.co.nz/product.php?e=545235

Silverstone Strider Essential ST50F-ES 500W Single +12v rail - 34Amp
http://pricespy.co.nz/product.php?e=545236

Which of these would be able to run a HD7770 or HD7850 without much overkill?

Thanks alot guys

 

[ko888]

For a system using a single reference design Radeon HD 7850 graphics card AMD specifies a minimum of a 500 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 27 Amps or greater and have at least one 6-pin PCI Express supplementary power connector. Some of the non-reference design Radeon HD 7850 graphics cards require at least two 6-pin PCI Express supplementary power connectors.

The Silverstone Strider Essential ST50F-ES 500W is your safest option.

 

[solvectro]

What about for the HD7770? Would the Antec work fine under extended periods of gaming?

 

[ko888]

What about for the HD7770? Would the Antec work fine under extended periods of gaming?

For a system using a single Radeon HD 7770 GHz Edition graphics card AMD specifies a minimum of a 500 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 23 Amps or greater and have at least one 6-pin PCI Express supplementary power connector.

The Antec VP Series 450 Watts (VP450P), with its maximum combined +12 Volt continuous current rating of 30 Amps and with one 6-pin PCI Express supplementary power connector, is more than sufficient to power your system configuration with a single Radeon HD 7770 GHz Edition graphics card.

 

[solvectro]

Best answer selected by solvectro.

 

[solvectro]

Cheers, thanks alot for the concise answers