Antec Basiq 550W not enough for HD 7870

I have recently completed making myself a new rig which is working fine but the only problem that I am facing is with the graphics card. Since I have got a Antec Basiq 550W, it seems that it is not capable enough to run Radeon HD 7870 with not enough amperage off the 12V rail. When I checked the video card then I noticed that it requires atleast 30A off the 12V rail. But when I checked the PSU then it says it gives 25A. I even tried to plug in 2 PCIe power cords but with 2 different 12V rails, but the monitor was not displaying any output at all. Can anyone please help me to get this graphics card to work? Thanks

If you are using single video card of Radeon HD 7870 then a minimum of 500Watt or greater power supply is needed, and also specified by AMD manufacturer. The same PSU must also have a +12V continous current rating of 27 Amps or higher and 2 PCIe 6-pin power connectors for the card. The main thing to be considered in a Power Supply is to have a Total Continuous amperage available on the +12V Rails rather than the wattage of the PSU.

One such basic Power Supply, with the consideration noted in the above post, that you can go for is CoolerMaster Real Power Pro 550W. It comes with 2 6-pin PCIe power connectors combined with +12v continuous current rating of 36 amps as well. Below is its main features:

1. Comply with the new Intel standard ATX 12V V 2.02 and also the new standard SSI EPS 12V V2.1
2. Compliant with nVIDIA SLI specification
3. Super silent with Intelligent system fan speed control
4. Power Management with HCI (Human Computer Interface)
5. PCI-e connectors
6. Supports output +12 V, +12 V2 and +12 V3
7. Green power design
8. More than 75% efficiency
9. High reliability (MTBF> 400,000 hours)
10. OVP/OCP/OTP/OLP/Short/Full protection
11. Active Power Factor Correction (PF> 0.99)

Even I agree that the Antec Basiq 550W will not work with HD 7870 because of the low number of rails on the PSU, even though the power wattage is adequate. So, better go with CoolerMaster Real Power Pro 550W that comes with 6 other connectors which allows you to connect cables with three Molex (x2), 4 SATA (x2), and 2 molex and 1 floppy (x1). In practice RealPower unfortunately makes a bit of noise. Almost inaudible at low loads, it is noisy at half load and becomes very noisy beyond in normal.