Gigabyte Radeon HD 7970 SOC ReviewCelebrating Tahiti's "half birthday" last month, AMD relaunched its
Radeon HD 7970 with a factory-overclocked
"GHz Edition" offering that increased the reference design's core clock speed from 925MHz to 1GHz with the intention of claiming the company now offered the world's fastest GPU. Unfortunately, the festivities were short-lived for several reasons.
Not only was it already possible to buy an HD 7970 running at those speeds and beyond, but AMD wasn't truly able to nab the performance crown back from Nvidia as the HD 7970 GHz Edition and the
GTX 680 are about equal. Additionally, it was hard to get excited about such a marginal performance bump when it's associated with a $50 price hike.
To date, there are no official HD 7970 GHz Edition cards available and in hindsight, AMD could have collaborated with a board partner to deliver something more impressive. On the bright side, Gigabyte has taken matters into its own hands with the new HD 7970 SOC (Super OverClock) card, which seems to be far more interesting than AMD's solution.
It's been about a year since we reviewed the
Gigabyte GeForce GTX 580 SOC which pushed a hot GF110 GPU 10% harder and still managed to provide an impressive amount of overclocking headroom using Gigabyte's OC Guru software. The Gigabyte Radeon HD 7970 SOC is an entirely different beast that sets a new standard for extreme air-cooled graphics cards.
Armed with five fans, nine heatpipes and a king-sized vapor chamber, one might consider the HD 7970 SOC to be overkill, and to that we say "hell yes!"
Our inner enthusiast has a penchant for all things impractical -- even if they're tough to recommend from a value perspective. Let's move on and see what Gigabyte's premium offering brings to the table.
Super OverClock Radeon HD 7970 The herculean HD 7970 SOC measures 11.4" (29cm) long, which is the actual PCB length, as the cooler doesn't overhang the board. In comparison the PCB of the standard HD 7970 measures 10.4" (26.5cm) long and roughly 11.0" (28cm) with the cooler.
As you'd expect, Gigabyte has completely redesigned the HD 7970 PCB, upgrading various critical components. The company markets these upgrades under the "Ultra Durable VGA+? banner which includes NEC/TOKIN Proadlizer 5 (film capacitors) which are said to provide amazing current capacity and extremely low ESL/ESR for better overclocking. By using a bank of five proadlizers, they transmit more stable power even during heavy loads.
The HD 7970 SOC exclusively uses Japanese solid capacitors which contain a solid organic polymer, while electrolytic capacitors use a common liquid electrolyte. This is said to make them more durable while providing better electronic conductivity.
Gigabyte also uses Ferrite Core Chokes comprised of an iron-oxide compound that holds energy much longer than common iron-core chokes at high frequencies. Also used are Low RDS (on) MOSFET?s which are specially designed to produce lower switching resistance for faster electric current charging and discharging.
All this is found on a 2oz copper PCB, which is twice the amount of copper inner layer found on traditional PCBs. In the past, Gigabyte has said that doubling the amount of copper improves heat dissipation efficiency from critical areas of the component such as the GPU power zone.
More details and photos on the next page. Benchmarks follow right after that.
Test System Specs & 3Dmark 11 Core i7 Test System Specs
- Intel Core i7-3960X Extreme Edition (3.30GHz)
- x4 2GB G.Skill DDR3-1600(CAS 8-8-8-20)
- Gigabyte G1.Assassin2 (Intel X79)
- OCZ ZX Series (1250w)
- Crucial m4 512GB (SATA 6Gb/s)
- Gainward GeForce GTX 680 Phantom (2048MB)
- Gainward GeForce GTX 670 Phantom (2048MB)
- Gainward GeForce GTX 680 (2048MB)
- Gigabyte GeForce GTX 590 (3072MB)
- Gigabyte GeForce GTX 580 (1536MB)
- Gigabyte GeForce GTX 570 (1280MB)
- Gigabyte GeForce GTX 560 Ti (1024MB)
- AMD Radeon HD 7970 GHz Edition (3072MB)
- Gigabyte Radeon HD 7970 SOC (3072MB)
- HIS Radeon HD 7970 (3072MB)
- HIS Radeon HD 7950 (3072MB)
- HIS Radeon HD 7870 (2048MB)
- HIS Radeon HD 7850 (2048MB)
- HIS Radeon HD 6990 (4096MB)
- HIS Radeon HD 6970 (2048MB)
- HIS Radeon HD 6950 (2048MB)
- HIS Radeon HD 6870 (1024MB)
- Microsoft Windows 7 Ultimate SP1 64-bit
- Nvidia Forceware 301.42
- AMD Catalyst 12.7
According to 3Dmark 11 Pro, the Gigabyte HD 7970 SOC is 17% faster than a standard HD 7970 and 7% faster than the GHz Edition card. Without any voltage modifications, we were able to reach a core clock speed of 1.2GHz resulting in a score of 3362pts, 6% higher than Gigabyte?s factory overclock and 23% faster than the standard 7970.
Eventually, we arrived at a core clock of 1260MHz and 1600MHz for the GDDR5 memory which boosted the 3Dmark score to 3554fps -- 31% faster than the standard 7970 and quicker than both the previous-generation dual-GPU cards.
Benchmarks: Battlefield 3, Crysis 2 Compared to a standard HD 7970, Gigabyte's SOC offering was 19% faster at 2560x1600 while it was also 14% faster than the GHz Edition card. Our 1200MHz core overclock only boosted performance by another 2%, while 1260MHz was 6% faster, likely due to the massive increase in GDDR5 frequency.
Whereas the HD 7970 GHz Edition was slightly slower than the GTX 680, losing by 1fps, the HD 7970 SOC was 5fps faster. Meanwhile, our 1.3v overclock allowed the SOC card to match the performance of the dual-GPU GTX 590.
When testing Crysis 2 at 2560x1600, the HD 7970 SOC was 6% faster than the standard and GHz Edition cards, which scored an equal 32fps. Gigabyte's solution also managed to outpace the GTX 680, while our custom 1200MHz and 1260MHz overclocks boosted the performance by 3% and 6%, respectively. Again, this made the 1.3v configuration faster than the GTX 590.
Power Consumption & Temperatures At its factory settings, the Gigabyte Radeon HD 7970 SOC-equipped system consumed 359 watts, 1.4% higher than the GHz Edition and 8% higher than a standard 7970. Our 1.2GHz overclock only increased load consumption by 1.6%, however, when increasing the voltage to 1.3v to achieve 1.26GHz, the load draw increased 12% to 403 watts. That's a significant jump, though it's mostly justifiable when you consider the performance gains.
Gigabyte claims its WindForce 5X cooler reduces temperatures by 18% over AMD's reference design. We recorded a 15% drop, though it's worth noting that the HD 7970 SOC ships with a factory overclock and Gigabyte's 18% claim might be derived from running its product at the same speed as the reference card (925MHz). Nonetheless, 15% is quite impressive, as is the SOC unit's noticeably quieter operation.
Overclocking the HD 7970 SOC to 1.2GHz only increased the load temperature 6% to 72 degrees, while adding the extra voltage for our 1260MHz overclock elevated temperatures 19% to 81 degrees. Even so, at 81 degrees the heavily overclocked Gigabyte card is about the same temperature as AMD's GHz Edition. It also makes about the same amount of noise, so again, impressive results from Gigabyte.
Final Thoughts Gigabyte's Radeon HD 7970 SOC takes air-cooling to an obnoxious level and many enthusiasts will argue it's too large, too loud, too heavy, too expensive and simply too impractical. All of those points are valid, yet we don't mind. The way we see it, the HD 7970 SOC is
meant to be all of the above. It's supposed to be the most extreme HD 7970 money can buy, and there's no denying it accomplished that feat.
The card spans 11.4" (29cm), but why should you care? Most
enthusiast cases can handle that with room to spare -- though it also occupies three expansion slots, which could be a concern depending on your motherboard's layout and the number of expansion cards you need.
Surprisingly, the SOC was fairly quiet when gaming until we cranked the settings up to 1.3v and 1.26GHz, at which point it was about equal to the
HD 7970 GHz Edition. There is at least one glaring weakness on this front, however: the SOC uses 40mm fans that have to spin pretty hard to keep the card cool and they aren't exactly known for their long lifespan.
The SOC's 3.5lb body was a non-issue. We didn't spot any PCB flex, which is common in cards that weigh half as much. You can likely thank the rear-mounted aluminum heat spreader for this, as it distributes the load well.
All told, the card's weakest points are also its strongest if you intend to overclock heavily, which is precisely what the SOC is designed for. Although we arrived at a maximum overclock of 1.26GHz, this should only be used as a rough guide as seasoned overclockers may fare better.
Gigabyte expects the Radeon HD 7970 SOC to become available in early August and we believe it will retail for around $530. If this estimate is accurate, the 7970 SOC will be a bargain hunter's nightmare, costing 20% more than the standard
Gigabyte 7970 OC. But for those who appreciate the excessive side of computing, the HD 7970 SOC certainly delivers.
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