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Clearly, based on these results, the HD 6850 performance scales much better than the Radeon HD 6870. That card is also based on AMD's Barts architecture, which sits in the HD 6850, but it has a full working die where the HD 6850 has one processor cluster switched off.
An overclocked HD 6870, such as the HIS HD 6870 Turbo edition, isn't noticeably faster than a stock model, but the five per cent increase to the speed of a basic HD 6850 that Sapphire offers us here translates to at least the same sort of performance increase – and often more – in games at 1920 x 1080 resolutions.
That's rarely the difference between playable and unplayable, since no £170 card is struggling at that resolution these days, but it does make it almost comparable to the higher spec HD 6870, and raises it (just) clear of the 1GB version of a GeForce GTX 460.
If you want to push it even further, the Sapphire TriXX application for tuning clockspeeds and voltages is a likable and simple app that will let you get even more performance out of the HD 6850 Toxic.
Experienced overclockers will find it wanting, though, because the range of timings it opens up are limited and there's no panel for keeping track of on-board temperatures while you move clock speeds around.
Getting the board running stably at 850MHz was effortless, though.
It's not, however, the fastest card available for the price. Similarly overclocked GTX 460s are available for less, as is the Radeon HD 5850, which is more capable at higher resolutions.
It's a card we'd recommend if you want to tune it further than the factory settings and really customise your rig yourself, because the extra power connector gives you a lot of options to play with. For most other people, though, we'd be obliged to point you in the direction of cheaper cards that are faster out of the box instead.
We liked
The extra clockspeed translates directly into more frames per second, and the customised heatsink is quiet and good looking. Sapphire's overclocking app gives you plenty of control for getting even more out of the card, too.
We disliked
It still doesn't feel right recommending any HD 6850 variant without the usual price caveats. It's a good card, but the GTX 460 and HD 5850 would be the logical choices with this much to spend.
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