Sapphire 1GB HD 4870 Toxic

Verdict: A desirable card with a price to match.

The world of graphics cards is fiercely competitive. Manufacturers such as Zotac and Sapphire modify reference designs in a bid to stamp the cards with their own identity and to make them stand out from the crowd. More memory, quieter and more efficient coolers, and overclocked components are valid and common methods. Sapphire has used all these tactics on its Toxic 1GB HD 4870, with increased clock speeds, 1GB of GDDR5 memory and an excellent Vapor-X cooler. The card costs more than a standard 1GB HD 4870, but the important question is whether or not the various upgrades justify the extra cost.

Regular readers will be familiar with the technology used in the highly effective Vapor-X cooler, but here's a quick summary. The cooler uses the power of evaporation to quickly draw heat away from the GPU and memory. Fixed to the various ICs of the card is a sealed container inside which liquid boils, evaporates and condenses, throwing off loads of heat in the process. The pressure inside the evaporation chamber has been lowered to give the liquid a lower boiling point and increase efficiency. Three heatpipes transfer the heat from the top of the evaporation chamber into the radiators on either side of the 92mm fan.

While folding, the Vapor-X cooler cooled the Toxic's GPU to a healthy 19°C below the reference cooler. Even when the GPU is under full load, the 92mm fan is quiet.

This is just as well, since the Toxic is pre-overclocked, so its components run hotter than those of a stock-speed card. The GPU frequency has been raised by a conservative 30MHz from 750MHz to 780MHz, while the 1GB of quad-pumped GDDR5 runs at 1GHz (4GHz effective) rather than 900MHz (3.6GHz effective).

Armed with its factory overclocks and vapour chamber cooler, the performance of the Toxic was slightly greater than that of a standard 1GB HD 4870. A stock-speed Radeon 1GB HD 4870 managed a playable 25fps minimum and a 27fps average when playing Crysis Warhead at 1,280 x 1,024. The Toxic managed the same minimum frame rate, but added 2fps to the average, pushing it up to 29fps. At higher resolutions, the Toxic was consistently better than a stock-speed card, although it was still unable to provide a playable frame rate with all the detail options on full.

In Far Cry 2, the Toxic produced faster minimum frame rates than a standard 1GB HD 4870. At 1,680 x 1,050 with 2x AA, the difference was particularly notable, with the Toxic producing a 40fps minimum, while a reference card managed only 33fps. Playing Fallout 3 at 1,920 x 1,200 with 4x AA and 8x AF, the Toxic smashed the 39fps minimum of the reference design with a mighty minimum of 50fps.

Folding performance was the usual poor show we've seen from ATI cards of late, with only 3,507ppd generated from project p4755, which was worth 477 points. The card caused our test system to consume up to 286W when folding and 375W when running the X3 benchmark.

With such a formidable cooler bolted to the Toxic, you should be able to draw every last megahertz of overclocking potential from the GPU and memory. The GPU temperature peaked at just 71°C while running Warhead at 1,920 x 1,200, so we had no qualms about aggressively pushing up the clock speeds.

We managed to raise the GPU frequency from 780MHz to 825MHz, and the GDDR5 memory from 1GHz to 1.06GHz (4.24GHz effective). With this overclock, the minimum frame rate of Warhead at 1,280 x 1,024 rose to 27fps, an increase of 2fps. This may be a marginal increase, but it's still welcome, as the frame rate was hovering on the boundary of what we consider to be playable.

Conclusion

There's no doubt that the Sapphire 1GB HD 4870 Toxic is a desirable card. The 1GB version of the HD 4870 is excellent value in its reference guise, and Sapphire's Vapor-X cooler shaves up to 19°C from the GPU temperature of the bog-standard cooler. This Sapphire-only cooler is also quiet, and handles a large overclock well. Most games showed a marginal speed increase with the Toxic over a stock-speed card, although some benefited from higher clock speeds only at certain resolutions. The card's stumbling block is its price: the premium for the overclock and cooler amounts to roughly £40. If you're happy to pay the extra for this well-designed card, you'll be rewarded, but it's a shade too expensive for us to give the Toxic an unequivocal recommendation.