HEXUS.bang4buck and bang4watt
Putting all the numbers into perspective, let's take a closer look at overall performance and value for money.
In a rough-and-ready assessment of the cards' bang for buck, we've aggregated the frame-rates for all our gaming benchmarks, normalised them1 and taken account of today's pricing.
But there are more provisos than we'd care to shake a stick at. We could have chosen 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 tables below highlight a metric that should only be used as a yardstick for evaluating comparative performance with price factored in.
Value analysis at 1,920x1,080 |
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| Graphics card | Aggregate FPS | Normalised FPS1 | Approx. price | Bang4buck | Power consumption | Bang4watt2 | ||
| 2x Sapphire Radeon HD 7950 OC (3,072MB) | 549.20 | 437.40 | £750 | 0.58 | 330 | 1.33 | ||
| Sapphire Radeon HD 7950 OC (3,072MB) | 335.30 | 298.15 | £375 | 0.80 | 193 | 1.54 | ||
| 2x EVGA GeForce GTX 580 SC (1,536MB) | 548.80 | 454.40 | £770 | 0.59 | 536 | 0.85 | ||
| EVGA GeForce GTX 580 SC (1,536MB) | 311.90 | 266.15 | £385 | 0.69 | 262 | 1.02 | ||
Value analysis at 2,560x1,600 |
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|---|---|---|---|---|---|---|---|---|
| Graphics card | Aggregate FPS | Normalised FPS1 | Approx. price | Bang4buck | Power consumption | Bang4watt2 | ||
| 2x Sapphire Radeon HD 7950 OC (3,072MB) | 315.40 | 242.40 | £750 | 0.32 | 330 | 0.73 | ||
| Sapphire Radeon HD 7950 OC (3,072MB) | 201.00 | 121.50 | £375 | 0.32 | 193 | 0.63 | ||
| 2x EVGA GeForce GTX 580 SC (1,536MB) | 341.10 | 302.45 | £770 | 0.39 | 536 | 0.56 | ||
| EVGA GeForce GTX 580 SC (1,536MB) | 181.40 | 92.10 | £385 | 0.24 | 262 | 0.35 | ||
1 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.
2 the HEXUS.bang4watt score is a crude measurement of how much normalised performance the GPU provides when evaluated against system-wide 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 real-world Total War: Shogun 2.
Summary
It's important to remember that our bang4buck is based on a few titles and doesn't take other architectural advantages into account; power-draw, operating temperature and noise output isn't considered. For the purpose of this metric, we're evaluating how much gaming performance per pound each configuration offers.
The results are no surprise. Sapphire's Radeon HD 7950 OC is an outstanding performer at full-HD 1080p, and at £375 it offers more bang4buck than a £385 EVGA GTX 580 SC. But the tables are turned when multiple GPUs come into play, as a result of poor CrossFire scaling in a couple of titles, the NVIDIA cards are a safer bet in SLI.
