GFX Card Trouble

[Tech Muffinz]

So I bought an R9 280 a few days a go along with a 535W PSU. I installed them and I noticed that the GFX card is not as good as it should be. I get less FPS and performance than when i use my previous card. GTX 660 superclocked. Is this a faulty card, or is this a not strong enough PSU. Also, Could It be a bottleneck? (I don't think it is)

Also I tried Dual PSU. i took my old PSU and make it power only my GFX card and I made it The other one power everything in the system except the GFX card.

PC Specs:
AMD FX-6100 6 cores 3.3ghz
8 GB ram
535W PSU
MSI R9 280
Biostar A880GZ
2 TB Hard Drive

 

[Tech Muffinz]

Also I meant to state that I ran Firestrike Benchmark and the GPU was at 98% the whole time of the graphics test. The CPU was not at 100% it was from 20-60%

 

[Shaun o]

The card should require 280W or more when stressed.
One of the biggest flaws people forget about though is how many amps the Psu can also provide on the 12v power rail.
The 12v Pci-e connectors from the Psu to the 280 card use this.

When a Card states its power consumption in wattage and amps.
You still have to factor in what all the other components in the system use for example from the 12v rail.
Examples are optical drives hard drives, and or any other Pci or Pci-e based cards in the system.

If the Amp current is slightly below what the card needs then it will cause a problem.
Supply and demand.

So yes it could be a fact you need a better wattage psu and one with a higher amp rating for the 12v supply.

 

[Tech Muffinz]

how many amps whould you suggest? I have two Hard drives an optical drive and my 280.

 

[Tech Muffinz]

Also on MSI afterburner and GPU-Z the Voltage/VDDC are at a constant 1.25V. Could that mean it isn't getting enough power?