Under The Radeon HD 7970 Super Overclock's Hood
This model is not based on AMD's Radeon HD 7970 GHz Edition design, and we think that’s a good thing. A massive cooler invites us to see just how far we can overclock Gigabyte's board, and we haven't had good experiences with tweaking the GHz Edition card due to its PowerTune with Boost feature.
Gigabyte is actually fairly conservative with its factory-set 1080 MHz GPU frequency. Even AMD's reference design can hit that without much of an issue. Of course, we'll see how much further than that we can actually go.
Three gigabytes of GDDR5 memory operate at 1375 MHz, matching AMD’s reference design. This is a disappointingly low number, particularly since Gigabyte’s marketing materials originally claimed 1550 MHz. The modules themselves come from Hynix, and we did manage to push them beyond 1500 MHz on our own.
The Radeon HD 7970 Super Overclock features one dual-link DVI, one HDMI, and two mini-DisplayPort outputs. It's other specs are as follows:
| Header Cell - Column 0 | Gigabyte 7970 Super Overclock | AMD Radeon HD 7970 GHz Edition | AMD Radeon HD 7970 | Nvidia GeForce GTX 680 |
|---|---|---|---|---|
| Stream Processors | 2048 | 2048 | 2048 | 1536 |
| Texture Units | 128 | 128 | 128 | 128 |
| Full Color ROPs | 32 | 32 | 32 | 32 |
| GPU Clock | 1080 MHz | 1000 MHz Base1050 MHz Boost | 925 MHz | 1006 MHz Base1058 MHz Boost |
| Texture Fill Rate | 138.2 Gtex/s | 134.4 Gtex/s | 118.4 Gtex/s | 128.8 Gtex/s |
| Memory Clock | 1375 MHz | 1500 MHz | 1375 MHz | 1502 MHz |
| Memory Bus | 384-bit | 384-bit | 384-bit | 256-bit |
| Memory Bandwidth | 264 GB/s | 288 GB/s | 264 GB/s | 192.3 GB/s |
| Graphics RAM | 3 GB GDDR5 | 3 GB GDDR5 | 3 GB GDDR5 | 2 GB GDDR5 |
| Die Size | 365 mm² | 365 mm² | 365 mm² | 294 mm² |
| Transistors (Billion) | 4.31 | 4.31 | 4.31 | 3.54 |
| Process Technology | 28 nm | 28 nm | 28 nm | 28 nm |
| Power Connectors | 2 x 8-pin | 1 x 8-pin, 1 x 6-pin | 1 x 8-pin, 1 x 6-pin | 2 x 6-pin |
| Maximum Power (TDP) | 300 W | 275 W | 250 W | 195 W |
Although it looks impressive, Gigabyte's front shroud is purely cosmetic. The cooler is closed off and attached to the card’s PCB with six screws.
PCB Comparison
In the image above, Gigabyte's Radeon HD 7970 Super Overclock is up top and AMD's reference Radeon HD 7970 is below. It's easy to see the differences between them. In addition to a larger PCB, Gigabyte's card has a bigger VRM with higher-quality components.
The inductor coils and voltage transformers consist of encapsulated ferrite coils and low-RDS(on) MOSFETs, putting them in an entirely different league as AMD's own design. This should become an advantage in overclocking.
On the back of the Radeon HD 7970 Super Overclock we find five proadlizers (high-capacity tantalum polymer capacitors). The power circuitry explains why the card is as long as it is.
The back plate’s only function is to stabilize Gigabyte's 7970 so that it doesn’t bend under the heavy cooler's weight. As far as quality goes, the on-board components leave nothing to be desired.
