If you look at the mid-range graphics card market today, you’ll see two distinct clusters of products priced around Rs 8,000 and Rs 18,000, with nearly nothing in between. Nvidia’s GT 640 and GTX 650 are positioned slightly lower than AMD’s Radeon HD 7750 and 7770 in the Rs 6,500—9,000 range. On the other hand, the Radeon HD 7850 and 7870 sit somewhere below the GeForce GTX 660 and 660 Ti in the Rs 16,000—22,000 range. With the impending discontinuation of the extremely popular HD 7850 1GB, that middle area is in danger of becoming even emptier.
Luckily, AMD has sensed the gap and has decided to step in with a new model, the Radeon HD 7790. Cards based on this GPU will effectively replace the 7850 1GB, but at a lower price and potentially lower performance. Nvidia isn’t holding back either, and a beefed up variant of its GeForce 650 ti with “Boost” suffixed to it has also launched this past week. We’ll take a look at the latter GPU in its own review soon, but we’ve managed to take some preliminary scores that we’ll include for the purpose of comparison with today’s focus, the Radeon HD 7790.
Asus' DirectCU II cooler is less obtrusive than AMD's reference design
GPU Features and architecture
Surprisngly, the 7790 isn’t just a tweaked version of an existing card. AMD won’t have a whole new generation out till much later this year, but that apparently isn’t stopping it from creating all-new chips for the current generation. The 7790 GPU, codenamed Bonaire, is an all-new version of the familiar Graphics Core Next architecture that the entire 7000 series is based on. As compared to Cape Verde, aka the 7770, Bonaire comes with 14 compute units, which is AMD’s terminology for GCN’s modular execution blocks, each of which includes vector and scalar units, texture filters, a scheduler, and a small L1 cache block. For the purpose of comparison, Cape Verde comes with only 10 compute units. All of this translates to significantly higher processing bandwidth per clock cycle—AMD points out that the benefits will mainly apply to texturing and tessellation.
The other major improvement comes in the power savings department. Bonaire can adjust itself to finer-grained power states than its predecessors, and switch between them faster too. This lets the GPU cut out power which was previously required to keep itself ready to ramp up speed.
A full complement of ports on the rear panel
The Asus HD7790-DCU2 OC
Unusually, our very first review sample of an HD 7790 card is not an identical reproduction of the GPU vendor’s reference design. Asus has ditched AMD’s usual shroud in favour of its own copper-and-aluminum DirectCU II cooler. This card is clocked a mere 75 MHz faster than the stock 1 GHz speed; a barely noticeable difference. The memory runs at 1.6 GHz as opposed to the 1.5 GHz stock speed, pushing bandwidth up from 6.0 Gbps to 6.4 Gbps. Asus claims the DirectCU II assembly allows the card to run 20 percent cooler and significantly quieter, allowing for more overclocking headroom. Asus also provides its GPU Tweak utility to let users adjust voltages, fan speeds and various overclocking parameters.
The cooler sticks out way beyond the relatively stubby card’s end, and unfortunately hot air will blow out through the back as well as into your cabinet. The rear panel hosts the standard array of dual-link DVI, single-link DVI, DisplayPort and HDMI sockets, and there’s a lone six-pin ATX power connector on the other end. In operation, the fans were barely audible no matter how hard our tests pushed them. Temperatures also never rose above 54 degrees C under load. The DirectCU II unit only makes direct contact with the GPU itself, not the power circuitry or the RAM chips, but we suspect that cooling would be sufficient for moderate overclocking—as long as it’s done slowly and carefully.
Processor: Intel Core i7-2600K CPU @ 3.40GHz
Motherboard: GIGABYTE P67A-UD3R
Memory: G.Skill Ripjaws 8GB (4GB x 2) @1600MHz
Storage: Plextor PX-256M2S SSD (boot drive), WD Velociraptor 300GB (secondary)
PSU: Cooler Master Silent Pro 1000W
OS: Windows 7 Ultimate 64-bit
3DMark is a computer benchmarking tool created and developed by Futuremark Corporation to determine the performance of a computer's 3D graphic rendering and CPU workload processing capabilities. The latest version makes extensive use of all the new features in DirectX 11, including tessellation, compute shaders and multi-threading. We used the “Performance” preset for this benchmark.
Battlefield 3 is a first-person shooter video game developed by EA Digital Illusions CE and is based on the new Frostbite 2 game engine. The game only supports DX10 and DX11, which enables enhanced in-game destruction with Destruction 3.0, creating more refined physics than its predecessor and quasi-realtime radiosity using Geometrics' Enlighten technology. The game is a visual treat and a nightmare for graphics cards, which makes it perfect for our test. We used the “Ultra High” preset, Post AA – High, Blur – Full, Field of View – 90, Level – “Fear no Evil”.
Dirt 3 is a rallying video game and the third in the Dirt series of the Colin McRae Rally series, developed and published by Codemasters. The game is extremely scalable and features DX11 tessellation effects. We used the built-in benchmark tool, along with “Ultra” quality preset.
Metro 2033 is a first-person shooter video game that continues to bring even the toughest graphics cards down to their knees. The game has a lot of DX11 eye-candy, which really puts a strain on any GPU. All DX11 features were enabled for the benchmark and we used the “Tower” level for our test.
Batman: Arkham City
A sequel to Arkham Asylum, Arkham City features a more open world gameplay as well as DX11 elements. For this test, we disabled Nvidias’s PhysX, since it would be unfair to AMD’s cards. Everything else was maxed out.
Crysis 2 is a first-person shooter developed by Crytek and is based on the new CryEngine 3. Just like the first iteration of the game, Crysis 2 continues to be one of the best looking shooters to date. The settings used for this benchmark were ‘Ultra High’ preset in Adrenalin, DX11 and High-resolution texture patch.
Verdict and Price in India
The Radeon HD7790 handily outclasses the 7770 as expected, and also comes surprisingly close to the 7850 which still sells for a little bit more. It would have been a very compelling GPU had it not been for Nvidia's interference in the form of the GeForce GTX 650 Ti Boost, which defeats it in most gaming tests. The Boost should cost slightly more on the street, but its performance advantage makes up for that difference. Perhaps anticipating this, AMD is offering buyers of any 7790 card a free copy of Bioshock Infinite, one of this season's best rated games. The PC version retails at Rs 999, so you can count that as a neat value-add if you were planning to play it and hadn't bought it already.
A great card for Rs 11,000, but a little more money will buy better performance from Nvidia
If your budget strictly tops out at Rs 11,000, then this is the best card you can buy. The 7790 GPU is superior to its own predecessors and the competiton's offerings at the same price, and Asus' DirectCU II design gives this card a solid advantage that most reference design cards don't have. We're also impressed with the new GPU's power saving attributes, and the Bioshock Infinite bundle is admittedly tempting. Without any direct competition, this card would have won an unqualified recommendation from us, but sadly we have to admit that Nvidia's new offering provides better value for your money.
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