AMD seems to never tire of launching new graphics cards. We're still in the first quarter of 2012 and we've already enjoyed six new 7000-seres Radeons, but the red team's not going to stop there.
And perhaps with good reason. There's a chance NVIDIA will lay the smackdown on Radeon HD 7970 with the soon-to-be-unleashed GeForce GTX 680, but if that's the case, AMD already has its retaliation lined up in the form of the Radeon HD 7990.
The long-rumoured card will one day take its place atop the 7000-series food chain and, like the 6990 before it, will do so by employing two GPUs on a single PCB. This time around they'll be 28nm chips based on the GCN architecture and, according to Chinese website inpai.com.cn, each will feature the full complement of HD 7970 features.
That means a total of 4,096 processors (2,048 from each Tahiti XT core), 256 texture units, 64 ROPs and a massive 6GB of memory shared across GPUs via two 384-bit channels. So it's two 7970s in CrossFire on a single board? Not quite, as the leak intimates that each GPU will be clocked at 850MHz (down from 925MHz on the HD 7970) and the frame buffer will hit an effective 5,000MHz (down from 5,500MHz).
Either way, it'll be a monstrous card with a frightening price tag, and the same site suggests that the HD 7990 will launch as soon as April. Whether that's true or if this is just a bit of pre-Kepler noise remains to be seen, but here's a look at how the dual-GPU card could stack up to existing 7000-series range:
| GPU | Radeon HD 7990 (6,144MB) | Radeon HD 7970 (3,072MB) |
Radeon HD 7950 (3,072MB) |
Radeon HD 7870 (2,048MB) |
Radeon HD 7850 (2,048MB) |
|---|---|---|---|---|---|
| Codename | New Zealand | Tahiti XT | Tahiti Pro | Pitcairn XT | Pitcairn Pro |
| DX API | 11.1 | 11.1 | 11.1 | 11.1 | 11.1 |
| Architecture | GCN | GCN | GCN | GCN | GCN |
| Process | 28nm | 28nm | 28nm | 28nm | 28nm |
| Transistors | 4.3bn (x2) | 4.3bn | 4.3bn | 2.8bn | 2.8bn |
| Die Size | 352mm² (x2) | 352mm² | 352mm² | 212mm² | 212mm² |
| Processors | 4,096 | 2,048 | 1,792 | 1,280 | 1,024 |
| Default memory | 3GB (x2) | 3GB | 3GB | 2GB | 2GB |
| Compute units | 64 | 32 | 28 | 20 | 16 |
| Texture Units | 256 | 128 | 112 | 80 | 64 |
| ROP Units | 64 | 32 | 32 | 32 | 32 |
| GPU Clock (MHz) | 850 | 925 | 800 | 1,000 | 860 |
| Shader Clock (MHz) | 850 | 925 | 800 | 1,000 | 860 |
| GFLOPS | 6,963 | 3,789 | 2,867 | 2,560 | 1,761 |
| Memory Clock (MHz) | 5,000 | 5,500 | 5,000 | 4,800 | 4,800 |
| Memory Bus (bits) | 384 (x2) | 384 | 384 | 256 | 256 |
| Max bandwidth (GB/s) | 240 (x2) | 264 | 240 | 153.6 | 153.6 |
| Power Connectors | Unknown | 8+6 | 6+6 | 6+6 | 6-pin |
| TDP (watts) | Unknown | 250 | 200 | 175 | 130 |
| CrossFire Support | Unknown | 4-way | 4-way | 2-way | 2-way |
| Release MSRP | Very expensive | $549 | $449 | $349 | $249 |
