AMD is fully aware that details on the coming GT300 from NVIDIA implies something phat coming. AMD may not have restructured its graphics design in an equally drastic manner, but it has time on its side. AMD is hoping to deliver RV870 chip in late summer and perhaps as early as July. German site Hardware-infos has published some new rumors on AMD’s RV870 chip, which seems to confirm the names HD 5870 and HD 5870 X2.
If we move on to the actual graphics processor there are some substantial improvements over the RV770/790 chips. AMD hasn’t just expanded the number of shaders from 800 to 1200, it also increased the number of texture units to 48 [Editor’s note: should 60 if the scaling is linear] and doubled the number of ROPs from 16 with RV770 to 32 with RV870. Not to forget the support for DirectX 11.
The site also published a table that specifies the clock frequencies AMD will use with its new 40nm GPUs and it also reveals some bits on the theoretical performance.
| HD 4870 | HD 4870 X2 | HD 5870 | HD 5870 X2 | |
|---|---|---|---|---|
| GPU clock | 750 MHz | 2x 750 MHz | 900 MHz | 2x 950 MHz |
| Memory clock | 900 MHz | 2x 900 MHz | 1100 MHz | 2x 1150 MHz |
| Performance | 1200 Gflops | 2x 1200 Gflops | 2160 Gflops | 2x 2280 Gflops |
| Texture fillrate | 25.000 MT/s | 2x 25.000 MT/s | 43.200 MT/s | 2x 45.600 MT/s |
| Pixel fillrate | 10.000 MP/s | 2x 10.000 MP/s | 28.800 MP/s | 2x 30.400 MP/s |
| Bandwidth | 115,2 GB/s | 2x 115,2 GB/s | 140,8 GB/s | 2x 147,2 GB/s |
With 50% more shader units and higher clock frequencies, and perhaps tuned shaders too, it comes as no surprise that the performance will be reflected by that. Radeon HD 5870 will deliver 2160 Gflops, which is close to twice that of HD 4870.
Considering the pixel performance we see that the extra ROPs almost triple performance, which together with a higher clocked GDDR5 memory should result in some real pixel spraying mayhem.
Interestingly but perhaps not surprisingly, Radeon HD 5870 X2 looks to become a real beast, not just because they will get two RV870 chips on the same card, but also a frequency boost of 50MHz each.
We have no confirmation on these numbers and urge you to consider them with salt, but if AMD can get its RV870 GPU out by summer it is going to be one exciting fall waiting for NVIDIA to release its GT300.
