A full three months since the release of the Tahiti-based AMD Radeon HD 7970 every graphics card maker has issued at least one original variant of it. To emphasize the advantages of its brand, each product is made as different from the reference sample as possible and comes with a custom cooling system, pre-overclocked frequencies or even different BIOS settings in order to deliver higher performance at less noise.
The most advanced graphics cards of this kind feature custom PCBs with high-quality components, improved power circuitry and, possibly, double amount of onboard memory. Of course, it takes some time to prepare them for the market, so they come about later on. And now it's time for us to check out as many as three original Radeons from Gigabyte, Sapphire and XFX. We’ll measure their temperature and noise and evaluate their overclocking potential. As for performance tests, we will focus on benchmarking CrossFireX configurations built out of Radeon HD 7970s and Radeon HD 7950s. Let's get started!
Gigabyte Radeon HD 7970 Ultra Durable 3GB (GV-R797OC-3GD)
Gigabyte’s Radeon HD 7970 Ultra Durable is shipped in a large box covered with descriptions of product features.
We've got few accessories here: just two power cables, a CrossFireX bridge, a CD with drivers and an installation guide.
There are no adapters or video cables or discs with games in the box. The card comes to retail at $499 and its warranty period is 2 years.
Gigabyte's Radeon HD 7970 Ultra Durable looks more elegant and attractive compared to the reference AMD Radeon HD 7970 version. The face side of the PCB is covered by a glossy-black plastic casing with three fans:
The card measures 285x126x38 millimeters, which is a mere 7 millimeters longer than the reference Radeon HD 7970. It is equipped with one dual-link DVI-I connector, one HDMI and two mini-DisplayPorts:
Like with the reference sample, there’s a vent grid in the card’s mounting bracket above the connectors to exhaust the hot air out of the system case.
Again like the reference sample, the Gigabyte card has a BIOS switch, two MIO connectors for CrossFireX, and two power connectors:
The cooling system is fastened with only four screws, so it was easy for us to take it off. We then saw a 278-millimeter-long turquoise-colored PCB. It copies the reference PCB in design but has a much more attractive color.
Like the reference Radeon HD 7970, the Gigabyte card has a 5+1 power system with 5 phases for the GPU and 1 phase for the graphics memory.
Belonging to the Ultra Durable series, the product features high-quality components: a PCB with 2 ounces of copper, Japanese solid-state capacitors, ferrite-core chokes, and low RDS(on) MOSFETs. Consequently, Gigabyte claims the card to have a 5 to 10% lower GPU temperature, 10 to 30% higher overclocking potential and 10 to 30% higher efficiency compared to the reference sample.
There is a CHiL Semiconductor CHL8228G controller managing the card's power supply:
Like on every other card of this series, the 28nm die of the Tahiti XT processor is slightly sunken below the protective frame:
The GPU has a standard Tahiti XT configuration but its 3D clock rate is increased from the standard 925 MHz to 1000 MHz. That’s a high, although not the highest, frequency as original Radeon HD 7970s go. The GPU voltage of our sample of the card is 1.175 volts. In 2D mode the card drops its GPU clock rate and voltage to 300 MHz and 0.85 volts, respectively.
The card is equipped with a total of 3 gigabytes of onboard memory in 12 FCBGA-packaged GDDR5 chips from Hynix Semiconductor, labeled H5GQ2H24MFR R0C.
Oddly enough, the Gigabyte card has the same memory frequency as the reference version, namely 5500 MHz. It's unclear why they didn't pre-overclock it at least by 300 MHz, considering that this series of graphics cards can usually overclock their memory to 7000 MHz and higher. Even if Gigabyte thinks that memory frequency isn't a decisive factor for this card's performance, they might have pre-overclocked it just for show.
Here are the Gigabyte Radeon HD 7970 Ultra Durable specs and the card’s GPU quality level as reported by GPU-Z:
Now let’s take a look at Gigabyte’s exclusive cooler Triangle Cool:
It is rather simple in design. The heatsink consists of three sections, two of which are made of slim aluminum fins press-fitted onto three 6mm heat pipes whereas the middle one, also made of aluminum fins, is attached to the aluminum base.
This heatsink would be of the direct-touch variety if Gigabyte didn’t have to solder an additional copper plate to the heat pipes to ensure proper contact with the sunken-in GPU die. The whole arrangement is cooled by three 80mm fans with translucent impellers. Their speed is PWM-regulated automatically.
We checked out the card’s temperature while running Aliens vs. Predator (2010) in five cycles at the highest settings (2560x1600, with 16x anisotropic filtering and 4x antialiasing). We used MSI Afterburner 2.2.0 Beta 15 and GPU-Z 0.5.9 as monitoring tools. This test was carried out with a closed system case at an ambient temperature of 26°C. We didn’t change the card’s default thermal interface.
While testing this card, we found BIOS version F2 being available for download from Gigabyte's official website. The new BIOS is claimed to optimize the cooler's fan speed. So, let's see if there are any changes in the automatic fan regulation mode:
It’s clear that the graphics card is quieter with the newer BIOS (the max speed of the fans is 3470 RPM before and 2560 RPM after the update) while the GPU temperature only rises by 4°C (from 62 to 66°C). Gigabyte's original cooler looks highly efficient overall.
At the maximum speed of 4590 RPM, the GPU was only 61°C hot:
Do not forget that the Gigabyte card's GPU is pre-overclocked to 1000 MHz as opposed to the reference Radeon HD 7970's 925 MHz.
As for further overclocking, our sample of the card could only reach a GPU clock rate of 1070 MHz:
The GPU was 69°C hot and the top speed of the fans in automatic mode was 2890 RPM.
When we increased the voltage from the default 1.175 to 1.250 volts, the CPU was stable at 1165 MHz.
Working at this frequency, the GPU was 71°C hot and the top speed of the three fans in automatic mode was 3150 RPM.
Considering the frequency and voltage of the overclocked GPU, we should praise Gigabyte’s cooler once again. The graphics memory could be overclocked from 5500 to 6840 MHz (+24.4%).
We guess we should tell you about one peculiar feature of our sample of the Gigabyte Radeon HD 7970 Ultra Durable. Ours turned out to be a musical card as its chokes emitted a hiss whenever we launched a 3D application. The hiss was as strong as to drown out the sound of the card's cooler. Of course, it was all rather uncomfortable, but the problem seems to be limited to the specific sample we’ve got for our tests. The positive side for us was that we could easily identify by that hiss whether CrossFireX mode worked or not (and even how effectively it worked!) when our Gigabyte Radeon HD 7970 Ultra Durable was set as the slave card.