Dual-GPU Tahiti cards have been available on the market for quite some time now, but they were limited to just a couple of brands. Today marks the launch of AMD's Radeon HD 7990 reference design, making this card a lot more widespread. AMD's Radeon HD 7990 features a pair of 28nm Tahiti GPUs with 2048 stream processors per core, a 384-bit memory bus and 3GB GDDR5 memory per chip. The core clockspeed is 950MHz (1000MHz with boost) and the memory is clocked at 6000MHz. The card has a TDP of 375W and draws power from two PCIe power connectors.
Pricing of the card is $999, similar to NVIDIA's GeForce GTX 690, and you can expect retail availability in about two weeks. One thing to take into consideration though is that you receive a whopping eight free games with this card under AMD's Never Settle gaming bundle: Far Cry 3, Far Cry 3: Blood Dragon, Crysis 3: Hunter Edition, Bioshock: Infinite, Tomb Raider, Hitman Absolution, Sleeping Dogs, and Deus Ex: Human Evolution.
Lets take a look at a pair of reviews to get a sense of how AMD's latest flagship performs. First up is AnandTech, the site says the card delivers roughly 100% of the performance of the GTX 690, but notes they still need to do frame interval benchmarking to make a final determination on performance. One area where the Radeon HD 7990 fails to match the GTX 690 is power consumption, its TDP of 375W is significantly more than the GTX 690's 300W, but the Radeon HD 7990 does offer 2GB GDDR5 memory more than the GTX 690. Ultimately, AnandTech feels this card should have arrived roughly a year ago and notes it's hard to get excited about a dual-GPU card with this kind of performance at this stage in the game:
Regardless, the end result is that AMD is delivering the dual-GPU Tahiti card the world has been waiting for roughly a year later would be expected. Being late doesn’t make it a bad card, it’s just hard to get excited about a dual-GPU card with this kind of performance at this stage in the game. Anyone still in the market for such a card is going to be pleased to have more options, but otherwise most hardcore gamers have probably upgraded to something like 7970CF or GTX 690 in the intervening 12 months.
TPU writes AMD's Radeon HD 7990 shows excellent performance in games where CrossFire is working as intended, but notes that in five out of eighteen games that make up TPU's tests, CrossFire didn't scale or showed negative scaling.
To look at things from a different perspective, we created a second set of performance summary graphs that excluded all these problematic games, representing a scenario better suited to CrossFire usage, but the HD 7990 still only managed to beat the GTX 690 by 6% at 2560x1600, which is hardly a convincing result with the scaling issues looming in the background. Some people might argue that we could see better CrossFire scaling in the future because AMD graphics technology will power all future consoles, but I'm not so sure about that. Console developers don't develop for CrossFire and are happy that they only have to support a single hardware configuration.>/blockquote>