HEXUS.bang4buck and bang4watt
Putting all the numbers into perspective, let's take a closer look at overall performance.
In a rough-and-ready assessment of the cards' bang for buck, we've aggregated the 1,920x1,080 frame-rates for six games, normalised them* and taken account of the single-cards' prices.
But there are more provisos than we'd care to shake a stick at. We could have chosen six different games, the cards' prices could have been derived from other sources and pricing tends to fluctuate daily, especially for new-release GPUs.
Consequently, the table below highlight a metric that should only be used as a yardstick for evaluating comparative performance with price factored in. Other architectural benefits are not covered, obviously.
| Aggregate FPS (1,920x1,080) |
Normalised* FPS (1,920x1,080) |
Current pricing | bang4buck (1,920x1,080) |
Power consumption** | bang4watt*** (1,920x1,080) |
|
|---|---|---|---|---|---|---|
| Sapphire Radeon HD 6790 1,024MB | 264.30 | 206.20 | £120 | 1.72 | 93 | 2.22 |
| AMD Radeon HD 6790 1,024MB | 269.00 | 212.50 | £115 | 1.85 | 90 | 2.36 |
| Sapphire Radeon HD 6850 1,024MB | 332.50 | 284.85 | £140 | 2.03 | 82 | 3.47 |
| HIS Radeon HD 5770 1,024MB | 240.40 | 177.30 | £100 | 1.77 | 81 | 2.19 |
| Sapphire Radeon HD 5750 1,024MB | 210.30 | 135.45 | £90 | 1.51 | 56 | 2.42 |
| KFA2 GeForce GTX 550 Ti LTD OC 1,024MB | 310.10 | 263.15 | £140 | 1.88 | 110 | 2.58 |
| Gigabyte GeForce GTX 550 Ti OC 1,024MB | 298.60 | 254.10 | £130 | 1.95 | 102 | 2.49 |
| EVGA GeForce GTX 460 1,024MB | 349.50 | 302.55 | £140 | 2.16 | 120 | 2.52 |
| KFA2 GeForce GTX 460 768MB | 317.90 | 272.25 | £125 | 2.18 | 98 | 2.78 |
| Inno3D GeForce GTS 450 | 230.30 | 166.05 | £90 | 1.85 | 71 | 2.34 |
* the normalisation refers to taking playable frame rate into account. Should a card benchmark at over 60 frames per second in any one game, the extra fps count as half. Similarly, should a card benchmark lower, say at 40fps, we deduct half the difference from its average frame rate and the desired 60fps, giving it a HEXUS.bang4buck score of 30 marks. The minimum allowable frame rate is 20fps but that scores zero.
** the GPU power consumption is derived from subtracting a flat rate of 40W - indicating system power-draw without a card - from the Aliens vs. Predator load figure. While this figure isn't solely indicative of power pulled by the GPU, as the CPU also throttles up, it's a better metric than using peak system-draw alone.
*** the HEXUS.bang4watt score is a crude measurement of how much normalised performance the GPU provides when evaluated against GPU power-draw that's shown in the table: the former is divided by the latter. We're using the peak power-draw numbers obtained by running Just Cause 2.
Analysis
The HD 6790 does quite well until attention is turned to Star Craft 2, where 1080p performance is significantly lower than otherwise equivalent GeForce cards'.
Do the math and the HEXUS.bang4buck and bang4watt scores are handsomely bettered by the Radeon HD 6850 and, even, two pre-overclocked GeForce GTX 550 Tis.
