Sapphire HD 7790 Dual-X Video Card Review

Updated: March 23, 2013

While there are many different types of gamers, all of them want the same thing: Performance. The limiting factor for most though is budget. You may want to play the latest games at the absolute best settings, but you just don’t have the cash and yet still want to play. For that crowd there is always an entry-level video solution by both AMD and NVIDIA and this round we are talking AMD’s next entry into the foray; the all-new AMD Radeon HD 7790, a card meant to play at 1920X1080 at moderate settings. Based on an entirely new 28nm Graphics Core Next ASIC, AMD is looking to solidify their positing in this highly competitive market.

AMD has recently been touting that they would have cards based on their Sea Island chipset and the new Radeon HD 7790 is the first desktop card to make the light of day using the Bonaire series GPU. AMD recognized a gap in their VGA lineup as the 7770 was below the performance standard of their HD 7850 and they needed a card to balance this out and hence the HD 7790 was created. The previous generation Cape Verde GPU has some difference from the new Bonaire, those being the new Bonaire consists of 14 CUs, which breaks down to 896 stream processors along with 56 texture units, giving Bonaire 40% more shading and texturing performance than Cape Verde. Cape Verde had less Stream processors (640) and less texture units as well as having less available memory bandwidth as the Cape Verde was capable of 4.5Gbps and the Bonaire on the 7970 has a 6.0Gbps bandwidth approximately 33% faster than Cape Verde.

As far as the actual chipset die the HD 7790 lies somewhere between the HD 7770 GHz edition and the larger HD 7850 as seen by the graph shown below. Bonaire sits between Cape Verde and Pitcairn in transistor count and die size. Altogether Bonaire comes in at 2.08B transistors, occupying a 160mm2 die. This is as compared to Cape Verde’s 1.5B transistors and 123mm2 die size, or Pitcairn’s 2.8B transistors and 212mm2 die size. For AMD their closest chip in terms of die size in recent history would be Juniper, the workhorse of the Evergreen family and the Radeon HD 5770, which came in at 166mm2. The PCB is very Spartan on the new 7790 and the PCB sizes in under 7’’ long making it very easy to fit in smaller cases where size really matters. Most cards are around 4’’ in height and the HD 7970 is also in this range meaning that 2 space cases cannot be used due to the cards height. The Radeon HD 7970 is its own design and is a new ASIC in the AMD lineup of desktop graphics solutions.

The reference card from AMD is not over-clocked or cooled like the new Sapphire HD 7790 Dual-X OC that offers both out of box overclocking and an alternative and more robust Dual-X cooling solution. Not all of the cards that are being released by the various manufactures will be different than the reference AMD design, but some companies like Sapphire will go that extra step to make a better card for the enthusiast crowd. I am sure that a few other companies will follow this trend and we will see cards with all kinds of after market and non-reference based cards to choose from as the product begins to break into the market. The Radeon HD 7790 comes equipped with 896 Stream processors, 40 Texture units, 16 ROPS, 2.0 Billion Transistors, 1GB GDDR5 memory with a 128-Bit interface with total memory bandwidth of 6.0gbps. The Core clock is set at 1GHz and the card has 1.79 TFLOPS of total Compute Performance. Direct Compute performance on AMD cards many times outshines NVIDIA at the same level as NVDIA often times has stripped down the card (GK 104) in an effort to solely concentrate on gaming aspects. For many gamers this is a totally moot point, but for others who do other things beyond gaming this may be an imperative aspect in their choice of video solution. There are some games like Civilization V that uses Direct Compute to decompress textures on the fly and in those instances the 7970 performs very well and shows solid performance.

PowerTune Technology with Boost is AMDs all-in-one solution to control of your GPU’s various parameters and overclocking. The second-generation implementation of AMD PowerTune technology is designed to further provide higher sustained engine clocks, increased performance and improved power efficiency for the GPU on which this is applied. By utilizing 8 distinct clock & voltage DPM states, which is an increase from the previous 4-clock/voltage states. AMD PowerTune technology can ensure the GPU is running, at all times and at the optimal voltage for each clock speed being requested. My previous experience dictates that AMD is far more conservative with how far their Boost clocks allow as 50Mhz has so far been the most commonly seen Boost with NVIDIA usually going over a 100Mhz more. With water cooling and severe over-voltage more can be obtained, but that is manual overclocking, not Boost. Starting with 7790 and Bonaire, AMD has made changes to the way they handle voltage and clockspeed. Gone is pure clockspeed modulation – inferred states in AMD’s makeup and instead AMD is moving to using a larger number of full states. GCN 1.1 has 8 states altogether, with no inferred states between them. With this change, when PowerTune needs to reduce clockspeeds it can drop to a nearby state, reducing power consumption through both clockspeed and voltage reductions at the same time.

As far as the cards aesthetics go the card has a black PCB to go along with its plastic shroud that has the same color scheme. There are 2 fans located on the top of the card that are used to cool off the GPU and memory. You can see the aluminum fins and cooper heatpipe under the shroud when you turn the card on its side and this is all part of the Dual-X cooling solution. The cooling solution is very similar in looks to Sapphire’s Vapor-X although maybe a bit watered down since the card does not get nearly as hot as the 7970 did during testing. The card also features Flex technology that allows Eyefinity to use 3 monitors by DVI or HDMI and also four monitors using the standard display port connector. This will work well for someone in the business environment who needs to view multiple monitors, but the 1GB of memory will be the Achilles heel when trying to play 3D games at higher resolutions. As far as testing goes, we have continued to use the Red Dawn Extreme system for the last few months and will continue to do so until Haswell is released later this year. We run all the tests and games 3 times and then balance the scores as no two runs are identical and running them frequently may give slightly better accuracy, but it would be seriously time intensive and not enough to warrant doing, All the tests were ran at 1920X1080 as cards at this price level are not designed to handle high resolutions of 2560X1400 or higher. As you can see from our testing the new HD 7790 is indeed a much faster solution than the HD 7770 for only a few dollars more at the sales counter. At 1080p, which is the sweet spot for VGA cards, this card performs very well and from what we hear, CrossFire scaling is very nice as well.

Performance & Benchmarks

The main competition at this price point is the NVIDIA GTX 650 Ti, and the new AMD 7790 outperforms it in every test but two, which are both NVIDIA favorable tests that is no surprise to most users. Both Batman and Resident Evil 6 showed better scores on the GTX 650 Ti over the HD 7790 and this is to be expected with NVIDIA bound games. The card does run a bit hotter than the HD 7770 and the GTX 650 Ti and that may have to do with early drivers that do not adequately control the fan speeds during operation and more fan tuning may be in order. The card ran a bit hotter than the other cards that we tested though and that is most likely due to the fact that the card is basically overclocked right out of the box with everything already turned up for performance gains. For the moment, AMD holds the title for VGA card king at this price level, but NVIDIA as a serious competitor, will most likely have a counter product very soon and could once again shake up the tree. The card should be available through the retail chain by next Tuesday, so for those looking to purchase the card, your wait time will be short. Some of the real highlights of the card are its ability to handle 4 monitors via Flex technology, a great thing for business users, as well as Direct Compute that works well for those doing video editing. With that and its ability to handle the latest games in a 1920X1080 resolution with everything turned up to its High settings the card offers solid results. At the end of the day, the new Radeon HD 7790 is a great addition to the AMD lineup and fits perfect into their product offerings. This product qualifies for a Top Value Award, as it is very solid and well-priced product for the category it is competing in and deserves recognition. Sapphire has taken the new HD 7790 from its reference design into something with just a little bit more by way of better cooling and overclocking. Are you an AMD fan? How do you feel about this new product and how it fares against other cards in this price range? Like always thank you for taking the time to read this review and we appreciate your comments below as you and your opinions matter here on Tech Of Tomorrow.