Gigabyte Radeon HD 7970 3GB OC Review

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Taking Image Quality to the Next Level

Taking Image Quality to the Next Level

In this section we take a number of games we have tested previously in this review and bring things to the next level by pushing the in-game settings to the highest possible level. All other methodologies remain the same.

Crysis 2

Dirt 3

Metro 2033

Shogun 2: Total War

The Witcher 2

 

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Temperature & Acoustics / Power Consumption

Temperature Analysis

For all temperature testing, the cards were placed on an open test bench with a single 120mm 1200RPM fan placed ~8” away from the heatsink. The ambient temperature was kept at a constant 22°C (+/- 0.5°C). If the ambient temperatures rose above 23°C at any time throughout the test, all benchmarking was stopped. For this test we use the 3DMark Batch Size test at its highest triangle count with 4xAA and 16xAF enabled and looped it for one hour to determine the peak load temperature as measured by GPU-Z.

For Idle tests, we let the system idle at the Windows 7 desktop for 15 minutes and recorded the peak temperature.

Gigabyte’s Windforce 3x cooler may be large but it is also one of the best performing heatsinks on the market. The combination of an extensive fin array and three large fans allow this HD 7970 to become the coolest running we have come across to date. Not only will this make overclocking a bit easier but we’re hoping that it will prolong the longevity of certain onboard components as well.

Acoustical Testing

What you see below are the baseline idle dB(A) results attained for a relatively quiet open-case system (specs are in the Methodology section) sans GPU along with the attained results for each individual card in idle and load scenarios. The meter we use has been calibrated and is placed at seated ear-level exactly 12” away from the GPU’s fan. For the load scenarios, a loop of Unigine Heave 2.5 is used in order to generate a constant load on the GPU(s) over the course of 20 minutes.

Along with great temperature results are these astoundingly low acoustical numbers. Considering that XFX’s card also sports a custom heatsink design, we really can’t fault Gigabyte in any way since they’ve show what it takes engineer a cooler that can boast ultra low temperatures alongside near silent operation. We really couldn’t have asked for more.

System Power Consumption

For this test we hooked up our power supply to a UPM power meter that will log the power consumption of the whole system twice every second. In order to stress the GPU as much as possible we once again use the Batch Render test in 3DMark06 and let it run for 30 minutes to determine the peak power consumption while letting the card sit at a stable Windows desktop for 30 minutes to determine the peak idle power consumption. We have also included several other tests as well.

Please note that after extensive testing, we have found that simply plugging in a power meter to a wall outlet or UPS will NOT give you accurate power consumption numbers due to slight changes in the input voltage. Thus we use a Tripp-Lite 1800W line conditioner between the 120V outlet and the power meter.

We don’t usually say much in this section since overclocked cards normally exhibit higher power consumption than reference models. Naturally, the Gigabyte OC follows this same trail regardless of its low temperatures which leads us to believe that AMD’s Tahiti XT core isn’t as susceptible to efficiency loss through heat as a core like Fermi was.

 

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Overclocking Results

Overclocking Results

Ah yes, overclocking. This is yet another area where the HD 7970 shines and Gigabyte’s WindForce 3X heatsink allowed us to push core speed to new heights but we were voltage limited due to a decision to stick to reference voltages. Nonetheless, nearly hitting the 1.2GHz mark with 24/7 stability is nothing to thumb our noses at and the OC was able to accomplish this without a massive increase in fan speeds. Memory speed meanwhile hit good levels as well.

Final Clock Speeds:

Core: 1198MHz
Memory: 6204MHz (QDR)

 

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Conclusion

Conclusion

For the time being, AMD’s HD 7970 sits atop the GPU market, holding the honor of being the fastest single core graphics card on the market. While that position may be challenged in the coming months by NVIDIA’s Kepler, at this point there just aren’t any alternatives if you want the highest possible in-game framerates. Gigabyte’s HD 7970 OC offers much of the same in terms of performance but it goes far beyond reference offerings in some other key areas.

Let’s start off this conclusion with something you were all watching out for: whether or not the overclock on this card made any difference. The short answer to that is an absolute “no”. Gigabyte may call this an “OC Edition” but the increase in clock speeds doesn’t improve gameplay in any way, shape or form. Bumping clocks by less than 10% is simply a quick and easy way for board partners to charge a premium on otherwise reference-based cards. On the flip side of that coin, even a small performance increase is better than nothing and like most other HD 7970 cards, this one has a ton of overclocking headroom.

Where Gigabyte’s HD 7970 stands above the competition’s shoulders is in the temperature and acoustics categories. The WindForce 3X heatsink with its Tri Cool design allows this card to reach extremely low temperatures for an air cooled solution while maintaining a nearly silent noise profile. Incredibly, this carries into the overclocking realm as well. Even with the card hitting upwards of 1.2GHz, we didn’t see temperatures exceed 77 degrees or acoustical readings above 50 decibels. To us, this alone is worth Gigabyte’s $50 premium over a reference design.

When first starting out on this review we had trouble finding justification for the HD 7970 OC’s price of $600 and based solely upon performance, it just isn’t worth this kind of money. However, after experiencing a cool running core and nearly silent fan speeds throughout testing this became one of our all time favorite products of the last few months. It embodies everything we could possibly want out of a high performance graphics card and due to the WindForce 3X heatsink, Gigabyte’s HD 7970 OC wins our Dam Innovative Award.