Nvidia Blackwell architecture GB20x specifications exposed

This year, NVIDIA will unveil the next generation of gaming graphics cards, the GeForce RTX 50 series based on the Blackwell architecture, expected to arrive as early as the fourth quarter. As with the previous GeForce RTX 30/40 series, the initial focus will be on high-end products, with the RTX 5090 and RTX 5080 debuting first.

According to earlier reports, the GeForce graphics cards based on the Blackwell architecture will feature five chips: GB202, GB203, GB205, GB206, and GB207, with corresponding memory bus widths of 512/384-bit, 256-bit, 192-bit, 128-bit, and 128-bit. The RTX 5090 will be equipped with the GB202, while the RTX 5080 will use the GB203. The new products will be manufactured using TSMC’s customized 4NP process, an improvement over the existing 4N process.

Recently, a netizen revealed the specifications of several chips, including:

• GB202 – 12×8, 192 SMs / 24,576 CUDA cores, 512-bit, GDDR7, 33% more CUDA cores than the AD102.
• GB203 – 7×6, 84 SMs / 10,752 CUDA cores, 256-bit, GDDR7, 5% more CUDA cores than the AD103.
• GB205 – 5×5, 50 SMs / 6,400 CUDA cores, 192-bit, GDDR7, 16.6% fewer CUDA cores than the AD104.
• GB206 – 3×6, 36 SMs / 4,608 CUDA cores, 128-bit, GDDR7, the same number of CUDA cores as the AD106.
• GB207 – 2×5, 20 SMs / 2,560 CUDA cores, 128-bit, GDDR6, 16.6% fewer CUDA cores than the AD107.

For example, the GB202 features 12 GPCs, each with 8 TPCs, and assuming each TPC has 2 SMs, this corresponds to 192 SMs. In specific products, some SMs might be disabled, and even the memory bus width might be reduced. It is said that the RTX 5090 will not utilize all SMs, and it is expected to use between 170 to 180 of them.

It can be seen that the high-end GB202 and GB203 have become larger in scale, while the GB205, which replaces the AD104, has decreased in size with its lower positioning. This is likely to correspond to the RTX 5070, which is not good news for mainstream users. Additionally, the entry-level GB207 has widened the gap with the GB206 and, due to cost and positioning considerations, is not equipped with GDDR7 but still uses GDDR6, although rumors suggest both might be supported.

Recent news from COMPUTEX 2024 indicates that the RTX 5080 is rumored to debut before the RTX 5090, although the release of the new graphics cards might be delayed until early 2025.