The above table shows currently known codenames and model designation for AMD's next generation 'Southern Islands' graphics cards.
The leak comes amidst AMD's vow to release 28nm graphics cards this year with Q4 dawning on us it would be no surprise to see some rumours and numbers bouncing around. While they are not confirmed and should be taken with a pinch of salt these leaks will always generate interest. Unfortunately there is nothing listed for the flagship dual 7990 but it is possible to go by the numbers of the 7970 and make an educated guess. Only the 7900 series cards will use the GCN (Graphics Core Next) architecture with Compute Units as well as using XDR2 memory, which Rambus touts to be the fastest memory system in the world, offering double the bandwidth per circuit of GDDR5 while using 30% less power. The rest of the 7000 series cards will be using the VLIW4 architecture first seen in the Radeon HD 6000 series though with improved SIMD wide-vector execution.
Other 7000 series notes are:
-Multiple primitive pipelines for setup, etc.
-Real caching in L1, L2, separate color / z caches for graphics and atomics
-Out of order resource allocation
-ECC on srams and drams
This chart shows a comparison of the HD 7970 vs HD 6970.
AMD Radeon HD 7000 Southern Islands 28nm
HD 7990 New Zealand GCN (no details) likely double 7970 with core/memory speed and TDP dependant on NVIDIA competition.
HD 7970 Tahiti XT GCN 1000MHz 32CUs 2048ALUs 128TMUs 64ROPs 256bit XDR2 8.0Gbps 256GB/s 2GB 190W HP
HD 7950 Tahiti Pro GCN 900MHz 30CUs 1920ALUs 120TMUs 64ROPs 256bit XDR2 7.2Gbps 230GB/s 2GB 150W HP
HD 7870 Thames XT VLIW4 950MHz 24SIMDs 1536ALUs 96TMUs 32ROPs 256bit GDDR5 5.8Gbps 186GB/s 2GB 120W HPL
HD 7850 Thames Pro VLIW4 850MHz 22SIMDs 1408ALUs 88TMUs 32ROPs 256bit GDDR5 5.2Gbps 166GB/s 2GB 90W HPL
HD 7670 Lombok XT VLIW4 900MHz 12SIMDs 768ALUs 48TMUs 16ROPs 128bit GDDR5 5.0Gbps 80GB/s 1GB 60W HPL
HD 7570 Lombok Pro VLIW4 750MHz 12SIMDs 768ALUs 48TMUs 16ROPs 128bit GDDR5 4.0Gbps 64GB/s 1GB 50W HPL
Interestingly it differentiates the 28nm fabrication used. Considering that there has been questions about the HP fabrication not being ready, this would suggest that the 7900 series will be released later than the HPL cards. So expect to see the 7870 hitting the shops first.
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