AMD’s next-generation family has long been referred to as “Southern Islands”, a codename revealed by SemiAccurate back in March. The recent Catalyst 10.8 codenames had “NI” suffixes all over, suggesting that Southern Islands is Northern Islands after all. SemiAccurate themselves confirm that AMD’s upcoming Radeon HD 6000 is indeed Northern Islands. Instead, it is the 28nm part which we referred to as Northern Islands which is the real Southern Islands. But, what’s in a name? The codenames suggest “Caribbean Islands” would be a more appropriate name! More importantly, several details about the Radeon HD 6000 series is revealed.

Read on for more details…

AMD’s next-generation family has long been referred to as “Southern Islands”, a codename revealed by SemiAccurate back in March. The recent Catalyst 10.8 codenames had “NI” suffixes all over, suggesting that Southern Islands is
Northern Islands after all. SemiAccurate themselves confirm that AMD’s
upcoming Radeon HD 6000 is indeed Northern Islands. Instead, it is the
28nm part which we referred to as Northern Islands which is the real
Southern Islands. But, what’s in a name? The codenames suggest
“Caribbean Islands” would be a more appropriate name! More importantly,
several details about the Radeon HD 6000 series is revealed.

As the rumour mill suggests, the first product will be the Radeon HD 6700 series, as direct competition to the GeForce GTX 460 in the $175-$250 range. However, the October 12th date is not the actual release, but an event, perhaps announcing the Radeon HD 6000 series. The actual release is set for around October 25th. As expected, the HD 6700 series will be followed by the HD 6800 and HD 6900 series, with entry-level and mainstream derivatives in early 2011.

The Radeon HD 6000 series, as we know, is somewhat of a makeshift generation, following TSMC’s late cancellation of 32nm. Earlier speculation suggested that the 32nm part, Northern Islands, was moved out to 28nm, with the 40nm Southern Islands being an intermediate generation with some features of the the 28nm part. However, in reality, it was Northern Islands which was pulled ahead to 40nm. Hence, the HD 6000 series could actually be a much more major upgrade than initially anticipated.

The HD 6000 series brings about the biggest architectural changes since R600 in 2007. AMD is finally splitting up the 4+1 shader cluster. Though a very useful feature when utilized, the final complex shader was rarely used in practical applications. Hence, out of the 1600 SP of the HD 5870, only about 1280 SP were in full utilization. HD 6000 cuts each shader cluster down to 4 shaders of medium complexity, rather than 4 simple + 1 complex. The end result is greater throughput as well as practical performance. In addition to this fundamental improvement, the NI uncore is also said to be improved. NI was designed for 32nm, however, and the cost of moving to 40nm means a large die size. SemiAccurate suggests 380-400 mm2 for Cayman / HD 6800 series. This still makes it much smaller than GF100’s 528 mm2. The performance is expected to increase much more than the 10%-20% increase in die size over the HD 5800 series, however.

Considering TSMC’s 40nm troubles, 32nm cancellation and 28nm delays, and sporadic competition from NVIDIA, many had feared that HD 6000 would only be a minor upgrade. It is clear that AMD is not resting on its laurels, and have gone all out to create a family worth of a new generation.

Reference: SemiAccurate