AMD reclaimed the top spot in the single-GPU category with the launch of the 7970 at the very beginning of January, at least until Nvidia comes back with a new flagship card for 2012. Meanwhile, AMD's ready to grab some new customers with a card that's nearly as fast as the 7970 but $100 cheaper. The 7950, which rings in at $450, is a direct competitor for Nvidia's GTX 580.
The Radeon 7950 drops its memory clock to 5GHz from the 7970's 5.5GHz and has fewer texture units and stream processors. The 100MHz difference in clock speed is somewhat offset by overclocking, however: Sapphire and MSI are both offering 7950s clocked at 900MHz, near the 7970's 925MHz base. Both are fast enough to surpass the GTX 580 in some benchmarks, but Anandtech and Tom's Hardware saw the two cards return surprisingly different results.
AMD's new 7950 doesn't offer dramatically better speeds than the year-old GTX 580, but it seems to overclock well and is dramatically less power hungry than the GTX 580 under load.
Take Dirt 3's benchmark, for example. While Anandtech got 71 frames per second in a 2560x1600 Ultra configuration with the 7950 and 4xAA, Tom's Hardware got only 51 fps with no AA. And where Anand saw the GTX 580 return about five fewer frames per second than AMD's card, Tom's Hardware saw them separated by 1 fps.
With the same settings in Metro 2033, Anandtech got 33 fps from the AMD 7950 and 27.5 frames out of the GTX 580. Tom's Hardware got 26.7 fps from the AMD card and only 22 fps from the GTX 580.
AMD's new 7950 will not offer dramatically better speeds than the year-old GTX 580, but it will get a nice speed boost in overclocked form and is dramatically less power hungry than the GTX 580 under load. Anandtech found that the overclocked Sapphire HD 7950 OE ran quieter cooler, and drew less power than any other card in its class. That looks like a strong contender for the 7950 model to get, at least from the initial batch of overclocked cards.
We have just received a 7950 reference board from AMD, and will be sharing our own benchmark numbers soon.