Next generation graphics cards from AMD is coming, and the first graphics circuit at 28nm has been dubbed Tahiti. Tahiti will be the top circuits that will be used in HD 7970, which specifications has leaked onto the web.
Det har länge skrivits om den nya grafikarkitekturen GCN (Graphics Core Next) från AMD, som blir deras första på åratal. Det första grafikkortet som kommer nyttja den purfärska arkitekturen heter HD 7970 vilket väntas bli företagets toppmodell med en GPU. Kretsen som driver den är Tahiti och bygger på TSMC:s senaste tillverkningsprocess på 28nm som effektivt ökar transistordensiteten tvåfaldigt mot 40nm.
| Model | Radeon HD 7970 | Radeon HD 6970 |
| Architecture | Southern Islands | Northern Islands |
| Node | 28nm | 40nm |
| Die size |
~380mm² | 389mm² |
| Circuit | Tahiti XT | Cayman XT |
| Transistors | ~4.5 billion | 2.64 billion |
| Radeon cores |
2048 | 1536 |
| GPU frequency |
925 MHz | 880 MHz |
| Memory bus |
384-bit | 256-bit |
| Memory buffer |
3 GB | 2 GB |
| Memory technology |
GDDR5 | GDDR5 |
| Memory freqyency |
1375 MHZz (5500 MHz effectively) |
1375 MHz (5500 MHz effektively) |
| Memory bandwidth |
264 GB/s | 176 GB/s |
| ROPs | 32 | 32 |
| Texture units |
128 | 96 |
HD 7970 that builds on the new GCN architecture sports 32 clusters with 32 execution units each. In total Tahiti and HD 7970 will sport 2048 Radeon cores, and increased the number of texture units from 96 in Cayman to 128. The number of ROPs remains the same; 32.
The memory controller has been upgraded from 256 to 384-bits with the same GDDR5 frequency. This will boost memory bandwidth with 50 percent, and it has also installed 3 GB memory. The card will consume 300W and below using one 8-pin and one 6-pin connector. The card sports four outputs; DVI, HDMI and two mini-DisplayPort.
Despite the turned up specifications AMD has reduced energy consumption when the card is idle. We see in the image above that compared to earlier generations, where HD 6970 consumes 24W at idle. HD 7970 will consume as little as 3W and below using AMD ZeroCore Power Technology, which more or less sounds like the card will turn off when not needed?
