The new Radeon HD 7790 is based on AMD's new Bonaire graphics core, which is an evolutionary step towards new GPU technology. It uses more shaders and a new dynamic clock algorithm that promises higher performance than AMD's original PowerTune Boost. In our testing, we see nice performance results that sit right in between the HD 7770 GHz Edition and HD 7850. This makes the HD 7790 capable of full-HD 1080p gaming, but in some titles, you might have to go easy on anti-aliasing levels, or reduce details slightly for the best gaming experience. Sapphire's HD 7790 Dual-X comes with a good increase on clock speeds out of the box. They provide another 5% real-life performance improvement.
Overclocking on our card worked amazingly well, reaching 1265 MHz GPU. Much better than the ASUS HD 7790 DC II that we also tested today. Real-life performance improvement after overclocking turned out to be 14.5%, which nearly resulted in HD 7850 performance levels. Unfortunately, voltage control is not possible at this time because all cards use a new voltage controller that is incompatible with current overclocking software. AMD has promised an updated SDK that adds voltage control for Bonaire in the future.
Sapphire went in with a board design that's quite close to reference, but they changed a few minor things around. The biggest change for you is certainly the 6-pin power connector's placement. It is now on the long edge of the card, like on recent NVIDIA cards. This makes plugging the power connector in and out much easier. Sapphire also included a little heatsink on the voltage regulators, which is a nice treat, even though I don't think such cooling is absolutely necessary.
The HD 7790 delivers excellent performance-per-watt numbers; actually, the card is the most power efficient one we have ever tested. This should provide a good idea of things to come for future Radeon graphics cards. In our testing, the card never exceeded 100W, not even in Furmark, so it will run perfectly fine with weaker power supplies—something that's important in this market segment. While slightly improved, Blu-ray power consumption is still not as good as that of NVIDIA's cards, but we are getting there.
Thanks to the low power consumption, heat output of the card is quite low, which means board partners can use less complex cooling solutions. Sapphire opted for a dual-fan design, and it delivers great temperatures. Noise levels in idle are great, and the card should be inaudible during desktop work. While gaming, fan speed will increase and end up noisier than I would have expected. The card is certainly not "loud," but it could do better in that department. With load temperatures of 60°C, Sapphire had plenty of headroom for better fan settings. The ASUS HD 7790 DC II that we also reviewed today does better here.
Pricing of the reference design HD 7790 is very reasonable with $149. Sapphire is asking a fair $10 price premium for their overclocked version with the better cooler. All HD 7790 cards come with a Bioshock Infinite game coupon—one of the most anticipated titles this season. If you don't need the game, you can easily sell the coupon for $20-$30, which helps offset the cost of the card. Compared to the GTX 650 Ti, costing $140 at this time, the HD 7790 is a bit faster but also a bit more expensive, so there is no clear winner here unless you factor in the game coupon that will make the HD 7790 the better deal. Sapphire also includes an HDMI cable with the card, which is nice, even if it only costs a few bucks. If you are willing to spend a bit more money, the HD 7850 is available for $180. It provides around 20% higher performance and comes with two game coupons (another $20 worth of resale value). There are many options in the sub-$200 segment right now, but you really can't go wrong with either choice—it all comes down to your budget.