EDIT: As some people have pointed out in this thread, the shader count may have been reported wrong but the CU is right because sisoftware sandra thinks each CU have 80 shaders and not 64 shaders.
Found this today at sisoftsandra.
According to the site, Tonga have in total 2240 shaders and 35CUs. The site also reports 28CU`s but that is only 1792 shaders (R9 285). The program doesnt put out 2240 shaders in random, so there got to exist a Tonga chip with that amount of shaders.
The memory bus is confirmed 256bit in total due to the 2GB VRAM (needs to be 1.5/3/6GB to be 384bit).
The GPU was tested just recently 3 days ago (R9 300 series?) and what is more interesting is that the GPU have 40% better speed efficiency than the R9 285 that was tested in 2014. 1.29MPix/s/Mhz vs 1.10MPix/s/MHz. AMD may have worked its magic to make it as efficient as they can to be ready to face Nvidia.
If you look at the score, 1194 Mpix/s (full Tonga) vs 1061 MPix/s (R9 285):
its 13% faster. But at the same time, the full Tonga only runs at 928MHz while the R9 285 runs at 965MHz. So if you take that in to consideration,
(35CU * 928MHz) / (28CU * 965MHz), you get +20%, not very far away from the score it was over the R9 285.
If this unknown GPU was also a 28CU, it would have scored 4% LESS than the R9 285. So we know it doesnt have that.
And on top of that we know that Tonga have a die size of 366mm2. The same die size as R9 280X which have 2048 shaders (like R9 285). BUT R9 280X have a 384bit memory bus that takes space, while Tonga have a smaller 256bit bus but have memory optimizations to help it. That should make more room for the additional shaders up to 2240 shaders.
Plus Tonga is GCN 1.2 while R9 280X is GCN 1.0. We know that AMD have made the chips denser from 1.0 to 1.1 so we should also assume the transistors on the full Tonga (1.2) is more dense than R9 280X making even more room for more shaders.
So to summarize:
We may have a full Tonga that have the following specs out soon:
R9 3xx: 35CUs, 2240 Shaders running at 928MHz. 2GB GDDR5 @ 256bit.
It will be placed in the R9 300 series somewhere, AMD seems to have saved it for when it was really needed. Which will be against the Maxwell series. Priced correctly it may not be a bad choice. We saw a 40% better efficiency vs the R9 285, so AMD seem to have tweaked the chip to get better performance out of it.
We know thanks to VR-zone that AMD plan to release Tonga for the 300 series under the name Antigua, so a full Tonga would be much better than releasing R9 285 again.
Found this today at sisoftsandra.
According to the site, Tonga have in total 2240 shaders and 35CUs. The site also reports 28CU`s but that is only 1792 shaders (R9 285). The program doesnt put out 2240 shaders in random, so there got to exist a Tonga chip with that amount of shaders.
The memory bus is confirmed 256bit in total due to the 2GB VRAM (needs to be 1.5/3/6GB to be 384bit).
The GPU was tested just recently 3 days ago (R9 300 series?) and what is more interesting is that the GPU have 40% better speed efficiency than the R9 285 that was tested in 2014. 1.29MPix/s/Mhz vs 1.10MPix/s/MHz. AMD may have worked its magic to make it as efficient as they can to be ready to face Nvidia.
If you look at the score, 1194 Mpix/s (full Tonga) vs 1061 MPix/s (R9 285):
its 13% faster. But at the same time, the full Tonga only runs at 928MHz while the R9 285 runs at 965MHz. So if you take that in to consideration,
(35CU * 928MHz) / (28CU * 965MHz), you get +20%, not very far away from the score it was over the R9 285.
If this unknown GPU was also a 28CU, it would have scored 4% LESS than the R9 285. So we know it doesnt have that.
And on top of that we know that Tonga have a die size of 366mm2. The same die size as R9 280X which have 2048 shaders (like R9 285). BUT R9 280X have a 384bit memory bus that takes space, while Tonga have a smaller 256bit bus but have memory optimizations to help it. That should make more room for the additional shaders up to 2240 shaders.
Plus Tonga is GCN 1.2 while R9 280X is GCN 1.0. We know that AMD have made the chips denser from 1.0 to 1.1 so we should also assume the transistors on the full Tonga (1.2) is more dense than R9 280X making even more room for more shaders.
So to summarize:
We may have a full Tonga that have the following specs out soon:
R9 3xx: 35CUs, 2240 Shaders running at 928MHz. 2GB GDDR5 @ 256bit.
It will be placed in the R9 300 series somewhere, AMD seems to have saved it for when it was really needed. Which will be against the Maxwell series. Priced correctly it may not be a bad choice. We saw a 40% better efficiency vs the R9 285, so AMD seem to have tweaked the chip to get better performance out of it.
We know thanks to VR-zone that AMD plan to release Tonga for the 300 series under the name Antigua, so a full Tonga would be much better than releasing R9 285 again.
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