Power Consumption (Idle and Gaming)

Putting a realistic, repeatable load on a GPU to get a decent idea of its real world power consumption and thermal output has long been something with which we've experimented here at bit-tech. We've found that synthetic benchmarks such as FurMark thrash the GPU constantly, which simply isn't reflective of how a GPU will be used when gaming.

It's such a hardcore test that any GPU under scrutiny is almost guaranteed to hit its thermal limit; the mark at which the card's firmware will kick in, speeding up the fan to keep the GPU within safe temperature limits. Conversely, simply leaving a game such as Crysis running at a certain point also isn't reflective of real-world use. There's no guarantee that the GPU is being pushed as hard as other titles might push it, and the load will vary between play-throughs.

We used to use the Canyon Flight test of 3DMark 06, as this was a punishing and repeatable test. However, we've now adopted Unigine's Heaven 3.0 benchmark, as its DirectX 11 features will stress all the parts of a modern GPU. We use the default settings and a resolution of 2,560 x 1,600. We then hit the Benchmark button and watch the power draw from the wall between the grass field scene and the second dragon scene - this is the toughest portion of the test for both Nvidia and AMD hardware.

Power consumption (idle)

Windows 7 Aero Desktop

  • AMD Radeon HD 7750 1GB
  • AMD Radeon HD 7770 1GB
  • AMD Radeon HD 7870 2GB
  • Nvidia GeForce GTX 650 1GB
  • AMD Radeon HD 7950 3GB
  • AMD Radeon HD 7970 3GB
  • Nvidia GeForce GTX 660 Ti 2GB
  • AMD Radeon HD 7950 3GB with Boost
  • Nvidia GeForce GTX 660 2GB
  • Nvidia GeForce GTX 670 2GB
  • AMD Radeon HD 7970 3GB GHz Edition
  • Nvidia GeForce GTX 680 2GB
  • Zotac GeForce GTX 660 Ti 2GB Amp! Extreme
  • AMD Radeon HD 7850 2GB
  • EVGA GeForce GTX 650 Ti 1GB SSC
  • Nvidia GeForce GTX 690 4GB
  • 71
  • 72
  • 75
  • 76
  • 80
  • 80
  • 80
  • 80
  • 80
  • 80
  • 80
  • 81
  • 85
  • 86
  • 87
  • 90
0
10
20
30
40
50
60
70
80
90
System Power consumption in Watts

Power consumption (load)

Unigine Heaven Benchmark (2,560 x 1,600, default settings)

  • AMD Radeon HD 7750 1GB
  • Nvidia GeForce GTX 650 1GB
  • AMD Radeon HD 7770 1GB
  • EVGA GeForce GTX 650 Ti 1GB SSC
  • AMD Radeon HD 7850 2GB
  • AMD Radeon HD 7870 2GB
  • Nvidia GeForce GTX 660 2GB
  • Nvidia GeForce GTX 660 Ti 2GB
  • AMD Radeon HD 7950 3GB
  • Zotac GeForce GTX 660 Ti 2GB Amp! Extreme
  • AMD Radeon HD 7950 3GB with Boost
  • Nvidia GeForce GTX 670 2GB
  • AMD Radeon HD 7970 3GB
  • Nvidia GeForce GTX 680 2GB
  • AMD Radeon HD 7970 3GB GHz Edition
  • Nvidia GeForce GTX 690 4GB
  • 112
  • 126
  • 145
  • 166
  • 173
  • 192
  • 205
  • 224
  • 227
  • 232
  • 240
  • 241
  • 265
  • 273
  • 314
  • 389
0
100
200
300
400
System Power consumption in Watts

Thermal Performance (Idle and Gaming)

We also have GPU-Z running in the background, and leave the Unigine benchmark running for ten minutes to record a peak GPU temperature. We present the temperature as a delta T (the difference between the temperature of the GPU and the ambient temperature in our labs).

Heat (idle)

Windows 7 Aero Desktop

  • AMD Radeon HD 7870 2GB
  • EVGA GeForce GTX 650 Ti 1GB SSC
  • Nvidia GeForce GTX 660 2GB
  • AMD Radeon HD 7770 1GB
  • Nvidia GeForce GTX 690 4GB
  • Zotac GeForce GTX 660 Ti 2GB Amp! Extreme
  • Nvidia GeForce GTX 660 Ti
  • Nvidia GeForce GTX 670 2GB
  • Nvidia GeForce GTX 680 2GB
  • AMD Radeon HD 7970 3GB GHz Edition
  • AMD Radeon HD 7750 1GB
  • AMD Radeon HD 7970 3GB
  • Nvidia GeForce GTX 650 1GB
  • AMD Radeon HD 7950 3GB
  • AMD Radeon HD 7950 3GB with Boost
  • 6
  • 8
  • 9
  • 10
  • 10
  • 10
  • 11
  • 11
  • 11
  • 11
  • 12
  • 14
  • 14
  • 15
  • 16
0
3
5.5
8
10.5
13
15.5
18
Delta T in °C

Heat (load)

Unigine Heaven Benchmark (2,560 x 1,600, default settings)

  • Nvidia GeForce GTX 650 1GB
  • EVGA GeForce GTX 650 Ti 1GB SSC
  • AMD Radeon HD 7870 2GB
  • Nvidia GeForce GTX 660 2GB
  • Zotac GeForce GTX 660 Ti 2GB Amp! Extreme
  • AMD Radeon HD 7750 1GB
  • Nvidia GeForce GTX 660 Ti
  • AMD Radeon HD 7770 1GB
  • AMD Radeon HD 7950 3GB with Boost
  • AMD Radeon HD 7970 3GB
  • AMD Radeon HD 7970 3GB GHZ Editon
  • Nvidia GeForce GTX 680 2GB
  • Nvidia GeForce GTX 670 2GB
  • AMD Radeon HD 7950 3GB
  • Nvidia GeForce GTX 690 4GB
  • 29
  • 37
  • 40
  • 41
  • 41
  • 42
  • 43
  • 44
  • 50
  • 53
  • 54
  • 54
  • 55
  • 57
  • 63
0
10
20
30
40
50
60
70
Delta T in °C

*as there's no stock model of the HD 7850 2GB, it is not included in these graphs

Read our performance analysis.

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