AMD Radeon HD 7790 Revealed



Product: AMD Radeon HD 7790
Company: AMD
Author: James Prior
Editor: Charles Oliver
Date: March 21st, 2013

Summary & Award

There are positives and negatives of filling in the blanks of product line up once you get a good grasp of the process technology, and the architecture. AMD has made a highly competitive mid-range GPU at a competitive price point. The problem is it makes me think that Cape Verde should never have been the 7700 series, but instead the 7600 series, and Bonaire was the 7700 all along - just delayed. What kind of delay? Perhaps the design team was on loan to another business unit, Playing around with the semi-custom guys who are Stationed in various now consolidated sites. Those GPU specifications sure seem familiar these days, minus a bit of memory bus width and the odd HSA specification or two. I wonder if these are, or will be, popular developer relations cards.

Radeon HD 7790 variable clock rate

The attention to power and efficiency shows in the HD 7790; it's a lot smarter about clock rate than the HD 7770 it outperforms so easily. It's got the measure of the GeForce GTX 650 Ti easily, but the HD 7850 already did that. However, the HD 7850 1GB is leaving the market due to lack of memory chips: 1 gigabit GDDR5 chips have ceased production, leaving the 7850 2GB at around $185. The Radeon HD 7790 pricing is good, and the free Bioshock Infinite game bundle is a very attractive value-add; a brand new triple-A game with a $150 GPU? Great stuff. The newest iteration of AMD Boost is the best yet - smooth and efficient and designed to run top GPU clock in all real world applications.

Where AMD needs a little more time is drivers; this card is fresh with dice in the mirror - Tomb Raider shows visual corruption, Unigine Valley has degraded performance in Crossfire, and Far Cry 3 stutters, worse so in Crossfire. AMD has a little bit of time to take review feedback onboard before the card hits the shelves, so there's hope for issue resolution. NVIDIA's drivers didn't give us any problems worth noting, and the smoothness index numbers speak volumes about where AMD has been optimizing to improve GCN cards, although rough spots definitely remain. We wouldn't advise Radeon HD 7790 Crossfire anytime soon; get a faster single GPU card for around $250-$280 instead.

AMD Radeon HD 7790 line up highlights

Both Sapphire and Gigabyte's custom designs are worthy of consideration, having advantages and disadvantages each. The better bundle is with the Sapphire card, with HDMI cable and Crossfire bridge; the Gigabyte card has dust protectors for all exposed ports and connectors. On balance I'd rather have the dust protectors, dust in long unused ports is the bane of troubleshooting new display or card configurations. However, the Gigabyte card's custom PCB also moves the Crossfire connector, making it just a few mm farther back from the backplate than reference design AMD cards. When trying to run Crossfire, this places stress on the Crossfire bridge, causing improper connections and ultimately blue screens. We were able to work around this issue by using adjacent PEG slots and a long Crossfire bridge, included with the Sapphire card (but not the Gigabyte one).

The custom heatsinks do their job, quietly. The Gigabyte card is easier to clean, the Sapphire card quieter under load even when pressed up against another card (in our case first our Creative X-Fi then the Gigabyte card). Sapphire pushes the edge a bit more with their 1600Mhz / 6.4Gbps memory clock, able to do so more comfortably because their heatsink covers all the memory chips, not just two like Gigabyte.

The embargo lift today on the 22nd means you've got time to consider the different partner options and wait and see what else appears before the mass availability date - April 2nd. Will there be some price war shenanigans before then, flubbing the value assessments of the cards published today? Gigabyte get 4 stars, you don't mess with connector placement, even with a nice compact PCB. We award the Sapphire Radeon HD 7790 Dual-X today's winner's medal, and our 4 1/2 star award. Tweak that PCB design a bit or ramp that clock a little harder, polish the drivers a bit harder, and it's a 5-star card.

Gigabyte GV-R779OC Award
Sapphire Radeon HD 7790 Dual-X OC Award