With our performance tests finished, we turn our attention to power consumption. The chart below shows total system power. But it begins at 57 W, which is the idle system use with its monitor output shut off. After all, our primary interest is each card's impact.

The XFX Radeon R7 240 wins this round with the lowest active idle and load power usage. Interestingly, the new Radeon R7 250 draws more power than the older Radeon HD 7750, likely due to its higher clock rates.
AMD's Radeon HD 7770 pays a price for its segment-leading performance; it's the only card requiring a six-pin auxiliary power cable.

When it comes to thermals, the results are definitely biased to the cards with non-reference coolers. XFX's Radeon R7 240 does well, while the R7 250 isn't as impressive. Then again, a 65 degree maximum load temperature is low compared to what we're used to on the high-end graphics side.
- The Sub-$100 Graphics Card Market
- Introducing The Radeon R7 240 And 250
- Test Setup And Benchmarks
- Results: Metro: Last Light
- Results: Grid 2
- Results: BioShock Infinite
- Results: Battlefield 4
- Results: Assassin's Creed IV: Black Flag
- Power And Temperature Benchmarks
- When It Comes To Graphics, $100 Goes A Long Way
A 400W is overkill if you're running a power-efficient CPU.
Look at the results, the most this system puilled with the R7 240 is 122 Watts under load. That's the whole system, with an overclocked Core i5-2500K!
A good 250W PSU should be fine. AMD is kind of recommending overkill here, but they do that to protect people from poor quality PSUs. A 250W HP shouldn't be a problem as long as the platform isn't power hungry.
Watch the language - G
Watch the language - G
A 400W is overkill if you're running a power-efficient CPU.
Look at the results, the most this system puilled with the R7 240 is 122 Watts under load. That's the whole system, with an overclocked Core i5-2500K!
A good 250W PSU should be fine. AMD is kind of recommending overkill here, but they do that to protect people from poor quality PSUs. A 250W HP shouldn't be a problem as long as the platform isn't power hungry.
*EDIT BY EDITOR*
You're absolutely right! We fixed the charts, thanks for catching that!
A good 250W power supply will have 18-20 amps on the 12V rail, which is fine for the R7 240.
I don't know why you bring up the 7770, it clearly draws a lot more power than the R7 240.
We were talking about the R7 240, not the 7770.
Even the 7770 is only a ~86W card... just barely high enough to require a 6pin PCIe power connection.
What? What the heck are you talking about?