HEXUS.bang4buck, temps, and overclocking
HEXUS.bang4buck.
In a rough-and-ready assessment of the cards' bang per buck, we've aggregated the 1920x1200 frame rates for the three games, normalised them* and taken account of listed the cards' current pricing.
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 iChiLL GeForce 8800 GT 512MiB | ZOTAC GeForce 8800 GT 512MiB AMP! Edition | ZOTAC GeForce 8800 GTS 512MiB AMP! Edition | Sapphire Radeon HD 3870 Atomic 512MiB | HIS Radeon HD 3870 X2 1,024MiB |
|---|---|---|---|---|---|
| Actual aggregate marks at 1920x1200 | 146.06 | 153.55 | 158.21 | 113.44 | 173.77 |
| Aggregate marks, normalised*, at 1920x1200 | 112.2 | 118.16 | 119.85 | 89.97 | 127.88 |
| Current pricing, including VAT | £189 | £199 | £229 | £175 | £290 |
| HEXUS.bang4buck score at 1920x1200 | 0.593 | 0.594 | 0.523 | 0.514 | 0.44 |
| Acceptable frame rate (av. 60fps) at 1920x1200 | No (ET, LP) | No (ET, LP) | No (ET, LP) | No (ET, LP) | No (ET, 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 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 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.
Decent gaming performance and a sub-£200 etail price produce an attractive HEXUS.bang4buck metric. You pay more for it than, say, the Sapphire Atomic card, but the increase in pure 3D performance is worth it when evaluated on our three games.
Temperatures
| Graphics cards | Inno3D iChiLL GeForce 8800 GT 512MiB | ZOTAC GeForce 8800 GT 512MiB AMP! Edition | ZOTAC GeForce 8800 GTS 512MiB AMP! Edition | Sapphire Radeon HD 3870 Atomic 512MiB | HIS Radeon HD 3870 X2 1,024MiB |
|---|---|---|---|---|---|
| Ambient temperature in degrees C | 22 | 21 | 18.5 | 17.5 | 19 |
| Idle temperature in degrees C | 43 | 52 | 58 | 48 | 56 |
| Load temperature in degrees C | 56 | 74 | 76 | 77 | 80 |
| Ambient-to-load delta in degrees C | 34 | 53 | 57.5 | 59.5 | 61 |
The Accelero X1 cooler is in a league of its own, clearly, and beats the pants off both the single- and dual-slot reference coolers found on the ZOTAC GeForce 8800 GT and GTS 512 cards.
Overclocking
The sample card was successfully overclocked from its default 700/1,500/2,000MHz clocks to 780/1,650/2,220MHz with complete stabiilty. Any higher on the core and we'd begin to see artifacts in Enemy Territory: Quake Wars. 2,250MHz memory was stable for around five minutes, we noted, and that's with no specific card-directed cooling in place.The extra clockspeed offered around 10 per cent more performance than the pre-overclocked numbers you see on the previous pages.
An above-average overclocker for the GeForce 8800 GT SKU but that could, and probably is, just be down to a press golden-sample model.
