Instinct MI455X vs B300 SXM6 AC
Contents
Primary details
GPU architecture, market segment, value for money and other general parameters compared.
| Place in the ranking | not rated | not rated |
| Place by popularity | not in top-100 | not in top-100 |
| Architecture | Blackwell Ultra (2025) | CDNA 5 (2026) |
| GPU code name | GB110 | MI450 256CU |
| Market segment | Workstation | Workstation |
| Release date | 11 September 2025 (1 year ago) | 23 July 2026 (less than a year ago) |
Detailed specifications
General parameters such as number of shaders, GPU core base clock and boost clock speeds, manufacturing process, texturing and calculation speed. Real power consumption of some graphics cards can well exceed their nominal TDP, especially if overclocked.
| Pipelines / CUDA cores | 18944 | 32768 |
| Core clock speed | 1665 MHz | 1000 MHz |
| Boost clock speed | 2032 MHz | 2400 MHz |
| Number of transistors | 208,000 million | 320.0 billion |
| Manufacturing process technology | 5 nm | 2 nm |
| Power consumption (TDP) | 1100 Watt | 2500 Watt |
| Texture fill rate | 1,202.9 | 2,457.6 |
| Floating-point processing power | 76.99 TFLOPS | no data |
| ROPs | 24 | no data |
| TMUs | 592 | 1024 |
| Tensor Cores | 592 | no data |
| L1 Cache | 37 MB | 16 MB |
| L2 Cache | 126 MB | 192 MB |
Form factor & compatibility
Information on compatibility with other computer components. Useful when choosing a future computer configuration or upgrading an existing one. For desktop graphics cards it's interface and bus (motherboard compatibility), additional power connectors (power supply compatibility).
| Interface | PCIe 6.0 x16 | PCIe 6.0 x16 |
| Width | SXM Module | EAM Module |
| Supplementary power connectors | no data | None |
VRAM capacity and type
Parameters of VRAM installed: its type, size, bus, clock and resulting bandwidth. Integrated GPUs have no dedicated video RAM and use a shared part of system RAM.
| Memory type | HBM3e | HBM4 |
| Maximum RAM amount | 288 GB | 432 GB |
| Memory bus width | 8192 Bit | 24576 Bit |
| Memory clock speed | 2000 MHz | 1900 MHz |
| Memory bandwidth | 8.19 TB/s | 23.3 TB/s |
| Resizable BAR | + | - |
Connectivity and outputs
This section shows the types and number of video connectors on each GPU. The data applies specifically to desktop reference models (for example, NVIDIA’s Founders Edition). OEM partners often modify both the number and types of ports. On notebook GPUs, video‐output options are determined by the laptop’s design rather than the graphics chip itself.
| Display Connectors | No outputs | No outputs |
API and SDK support
List of supported 3D and general-purpose computing APIs, including their specific versions.
| DirectX | N/A | N/A |
| Shader Model | N/A | N/A |
| OpenGL | N/A | N/A |
| OpenCL | 3.0 | 2.0 |
| Vulkan | N/A | N/A |
| CUDA | 10.3 | - |
| DLSS | + | - |
Pros & cons summary
| Recency | 11 September 2025 | 23 July 2026 |
| Maximum RAM amount | 288 GB | 432 GB |
| Chip lithography | 5 nm | 2 nm |
| Power consumption (TDP) | 1100 Watt | 2500 Watt |
B300 SXM6 AC has 127% lower power consumption.
Instinct MI455X, on the other hand, has an age advantage of 10 months, a 50% higher maximum VRAM amount, and a 150% more advanced lithography process.
We couldn't decide between B300 SXM6 AC and Instinct MI455X. We've got no test results to judge.
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