HEXUS.bang4buck, temps, power-draw, and overclocking
HEXUS.bang4buck.
In a rough-and-ready assessment of the cards' bang per buck, we've aggregated the 1,920x1,200 frame rates for the three games, normalised them* and taken account of listed the cards' prices.
But there are more provisos than we'd care to shake a stick at. We could have chosen three different games, the cards' prices could have been derived from other sources and pricing tends to fluctuate daily.
Consequently, the table and graph 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.
| Graphics cards | Inno3D GeForce 9800 GX2 1024MiB | Inno3D GX2 in SLI | BFG GeForce 9800 GTX | Sapphire Radeon HD 3870 X2 1024MiB | Sapphire HD 3870 X2 in CrossFire | Sapphire Radeon HD 3870 X2 1024MiB |
|---|---|---|---|---|---|---|
| Actual aggregate marks at 1920x1200 | 271.73 | 295.17 | 167.84 | 174.27 | 231.35 | 107.04 |
| Aggregate marks, normalised*, at 1920x1200 | 205.8 | 237.58 | 127.72 | 128.84 | 158.38 | 82.76 |
| Current price | £375 | £750 | £210 | £245 | £490 | £125 |
| HEXUS.bang4buck score at 1920x1200 | 0.549 | 0.317 | 0.608 | 0.526 | 0.323 | 0.662 |
| Acceptable frame rate (av. 60fps) at 1920x1200 | No (ET, LP) | No (ET, LP) | No (ET, LP) | No (ET, LP) | No (LP) | No (LP) |
* 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 bang4buck score of 30 marks. The minimum allowable frame rate is 20fps but that scores zero.
As an example, should a card score 120fps we treat it as 90fps as only half the frame rate above 60fps is counted for the bang4buck - this is the formula: (120-((120-60)/2)). Similarly, should it score 30fps, we count it as only 15fps: (30+((30-60)/2)).
The reasoning behind such calculation lies with playable frame rates.
Should card A score 110fps in a benchmark and card B 160, then card B would otherwise receive an extra 50 marks in our HEXUS.bang4buck assessment, even though both cards produce perfectly playable frame rates and anything above 60fps is a bonus and not a necessity for most.
Similarly, without our adjustments, the aggregated HEXUS.bang4buck total for two very different cards would be identical if, in a further benchmark, card A scored a smooth 70fps and card B an unplayable 20fps. Both would win marks totally 180, yet the games-playing experience would be vastly different.
A more realistic (and useful) assessment would say that card A is better because it ran smoothly in both games - and that view would be accurately reflected in our adjusted aggregation, where card A would receive 150 marks (85+65) and card B 100 (100+0).
In effect, we're including a desired average frame rate, in this case 60, and penalising lower performance while giving frame rates higher than 60fps only half as much credit as those up to 60fps. If this doesn't make sense or you have issue with it, please hit the HEXUS community.
Here's the HEXUS.bang4buck graph at 1,920x1,200.
The graph divides the normalised score by the price.
Power-draw and temperatures
Power-draw was measured with the systems at idle and with them running 3DMark06's Canyon test at 1,920x1,200 4xAA, 16xAF. The underlying platforms are listed on page four.| Graphics cards | Inno3D GX2 in SLI | Sapphire HD 3870 X2 in CrossFire |
|---|---|---|
| System wattage idle | 307 | 211 |
| System wattage load | 574 | 575 |
ATI's Radeon HD 3870 X2 GPUs consume considerably less when idling but around the same as a pair of GeForce 9800 GX2s when under load.
Bear in mind that we're looking at power-draw on a DDR2-based NVIDIA platform, and the quoted figures will drop a touch when using a DDR3-oriented nForce 790i Ultra SLI, for example.
An idle difference of ~100W may not sound like much, but it will cost a little extra each year to run. Not life-shattering amounts, sure, but money's money, right?
Both GeForce 9800 GX2 cards' GPUs idled at roughly 60°C, which rose to around 80°C under load, well within thermal specifications. Now, if only that cooler could be made quieter.
