AMD Instinct MI455X vs NVIDIA N1 16SM Comparison

Head-to-Head Benchmarks

The database records no direct head-to-head benchmark results between the AMD Instinct MI455X and the NVIDIA N1 16SM. Both entries carry an average benchmark score of 0 and a percentile ranking of 50 against all GPUs, which places them at the median of the recorded distribution but provides no comparative performance data. The absence of measured scores means the two accelerators cannot be ranked against each other through empirical testing in the current dataset.

The AMD Instinct MI455X delivers 157.3 TFLOPS of FP32 compute and an identical 157.3 TFLOPS of FP16 compute at a 1:1 ratio. The NVIDIA N1 16SM delivers 9.609 TFLOPS of FP32 and 9.609 TFLOPS of FP16, also at 1:1. The MI455X thus offers 16.4 times the raw floating-point throughput of the N1 16SM in both precisions, based strictly on the recorded specifications. Texture throughput follows a similar pattern: the MI455X reaches 2,457.6 GTexel/s, while the N1 16SM reaches 300.3 GTexel/s, an 8.2 times advantage for the AMD part. The N1 16SM counters with a pixel rate of 56.30 GPixel/s, while the MI455X records 0 MPixel/s, indicating the AMD accelerator lacks any rasterization output capability.

Memory bandwidth separates the two by an enormous margin. The MI455X uses 432 GB of HBM4 across a 24,576-bit bus, yielding 23.3 TB/s of bandwidth. The N1 16SM uses 128 GB of LPDDR5X across a 256-bit bus, yielding 273.2 GB/s. The MI455X delivers 85.3 times the memory bandwidth of the N1 16SM. The N1 16SM does retain a display output, a single HDMI port, while the MI455X lists no display outputs whatsoever. These recorded figures indicate the MI455X is oriented toward compute throughput, while the N1 16SM includes at least basic display functionality.

Architecture Differences

The two accelerators come from different architectural families and process nodes. The AMD Instinct MI455X uses the MI450 256CU chip built on CDNA 5.0 architecture, fabricated on a 2 nm process at TSMC. The NVIDIA N1 16SM uses the GB20B chip built on Blackwell 2.0 architecture, also fabricated at TSMC but on a 5 nm process. The MI455X belongs to the Instinct (MIx) generation, while the N1 16SM belongs to the Blackwell IGP (N1x) generation.

Transistor counts and die sizes diverge sharply. The MI455X integrates 320,000 million transistors on a 2,990 mm² die, yielding a transistor density of 107.0 million transistors per square millimeter. The N1 16SM lists an unknown transistor count on a 382 mm² die, with no density figure recorded. The MI455X die is 7.8 times larger than the N1 16SM die. The MI455X uses a 2 nm process, while the N1 16SM uses a 5 nm process, a two-generation gap in lithography.

The compute resources differ by an order of magnitude. The MI455X contains 32,768 shading units, 1,024 texture mapping units, and 0 ROPs. The N1 16SM contains 2,048 shading units, 128 texture mapping units, and 24 ROPs. The MI455X has 16 times the shading units and 8 times the texture units, but the N1 16SM has 24 ROPs where the MI455X has none. The N1 16SM also includes 16 ray tracing cores and 64 tensor cores, while the MI455X records no ray tracing cores and no tensor cores. Neither part lists DirectX, OpenGL, or Vulkan API support, indicating both are compute-oriented rather than graphics-oriented.

Clock speeds show a closer relationship than compute resources. The MI455X runs at a 1,000 MHz base clock and 2,400 MHz boost clock. The N1 16SM runs at a 741 MHz base clock and 2,346 MHz boost clock. The AMD part holds a 259 MHz base clock advantage and a 54 MHz boost clock advantage. The memory clocks differ: the MI455X runs memory at 1,900 MHz (7.6 Gbps effective), while the N1 16SM runs memory at 1,067 MHz (8.5 Gbps effective). The N1 16SM achieves a higher effective memory data rate despite the lower clock.

Memory technology and capacity reflect different design goals. The MI455X uses 432 GB of HBM4, while the N1 16SM uses 128 GB of LPDDR5X. The MI455X memory bus is 24,576 bits wide, compared to 256 bits on the N1 16SM. The power envelope also differs: the MI455X has a TDP of 2,300 W and a suggested PSU of 2,700 W, while the N1 16SM has an unknown TDP and no suggested PSU. The MI455X uses an EAM Module slot width with no power connectors, while the N1 16SM uses an IGP slot width, also with no power connectors. The MI455X interfaces via PCIe 6.0 x16, while the N1 16SM uses PCIe 5.0 x16.

Release dates place both in the same timeframe. The NVIDIA N1 16SM was released on 2026-05-31, and the AMD Instinct MI455X was released on 2026-07-22. The N1 16SM is listed as Active in production status, while the MI455X has no production status recorded. The MI455X lists Radeon Instinct as its predecessor, while the N1 16SM has no predecessor recorded. Neither part has a successor listed.

The Verdict

The recorded data shows two accelerators with fundamentally different roles. The AMD Instinct MI455X is a high-throughput compute accelerator with massive memory capacity and bandwidth, designed for workloads that scale across thousands of shading units and a 24,576-bit memory bus. The NVIDIA N1 16SM is a far smaller part with an integrated GPU form factor, a single HDMI output, and enough compute for lighter tasks.

For compute-intensive workloads, the MI455X dominates on every recorded metric that matters: FP32 throughput at 157.3 TFLOPS versus 9.609 TFLOPS, memory bandwidth at 23.3 TB/s versus 273.2 GB/s, and memory capacity at 432 GB versus 128 GB. Its 2,300 W TDP and EAM Module form factor indicate a rack-scale deployment rather than a desktop or embedded use case. The N1 16SM cannot compete on raw compute, but it does not need to; its IGP form factor, 24 ROPs, ray tracing cores, tensor cores, and display output suggest a different class of device.

The N1 16SM wins on form factor and integration. It fits as an IGP, includes 16 ray tracing cores and 64 tensor cores, and offers a display output, none of which the MI455X provides. Its 5 nm process and unknown TDP point to a lower-power design, though the database does not record a TDP figure. The MI455X wins on every compute and memory metric, but it requires a 2,700 W suggested PSU and occupies an EAM Module slot.

The data does not support a single winner across all use cases. The MI455X is the only choice for workloads demanding 157.3 TFLOPS of FP32 compute and 23.3 TB/s of bandwidth, such as large-scale training or inference with 432 GB of on-package memory. The N1 16SM is the only choice for systems needing a display output, ray tracing, tensor cores, and a compact IGP form factor, with 9.609 TFLOPS of compute available in a far smaller package.

FAQ

Q: Which accelerator has higher FP32 compute?

A: The AMD Instinct MI455X records 157.3 TFLOPS of FP32 compute, while the NVIDIA N1 16SM records 9.609 TFLOPS. The MI455X delivers 16.4 times the FP32 throughput.

Q: What are the memory capacities and types?

A: The MI455X uses 432 GB of HBM4 memory with a 24,576-bit bus and 23.3 TB/s bandwidth. The N1 16SM uses 128 GB of LPDDR5X memory with a 256-bit bus and 273.2 GB/s bandwidth.

Q: Does either part support display outputs?

A: The NVIDIA N1 16SM includes one HDMI output. The AMD Instinct MI455X lists no display outputs.

Q: Which architecture and process node does each use?

A: The MI455X uses CDNA 5.0 architecture on a 2 nm TSMC process. The N1 16SM uses Blackwell 2.0 architecture on a 5 nm TSMC process.

Q: What is the power requirement for the MI455X?

A: The MI455X has a TDP of 2,300 W and a suggested PSU of 2,700 W. The N1 16SM has an unknown TDP and no suggested PSU recorded.

Q: Which part has ray tracing and tensor cores?

A: The NVIDIA N1 16SM includes 16 ray tracing cores and 64 tensor cores. The AMD Instinct MI455X records no ray tracing cores and no tensor cores.

Where Each One Wins

The AMD Instinct MI455X wins on every raw compute and memory throughput metric. FP32 and FP16 performance both reach 157.3 TFLOPS, which is 16.4 times the N1 16SM's 9.609 TFLOPS in each precision. Texture rate reaches 2,457.6 GTexel/s, an 8.2 times advantage over the N1 16SM's 300.3 GTexel/s. Memory bandwidth of 23.3 TB/s is 85.3 times the N1 16SM's 273.2 GB/s. Memory capacity of 432 GB is 3.4 times the N1 16SM's 128 GB. The MI455X also holds higher base and boost clocks at 1,000 MHz and 2,400 MHz versus 741 MHz and 2,346 MHz.

The NVIDIA N1 16SM wins on integration and specialized features. It provides 24 ROPs, while the MI455X provides 0, giving the N1 16SM a pixel rate of 56.30 GPixel/s against 0 MPixel/s. It includes 16 ray tracing cores and 64 tensor cores, which the MI455X lacks entirely. It has a single HDMI display output, while the MI455X has no outputs. The N1 16SM uses an IGP form factor, while the MI455X uses an EAM Module, meaning the N1 fits in a far smaller physical footprint. The N1 16SM uses PCIe 5.0 x16, one generation behind the MI455X's PCIe 6.0 x16, but its 5 nm process and unknown TDP suggest a lower power draw, though the database does not confirm this numerically.

The MI455X also wins on memory clock at 1,900 MHz versus 1,067 MHz, though the N1 16SM achieves a higher effective data rate of 8.5 Gbps versus 7.6 Gbps. The MI455X has a larger die at 2,990 mm² versus 382 mm², and a higher transistor count at 320,000 million versus unknown. The MI455X was released later, on 2026-07-22 versus 2026-05-31 for the N1 16SM. The N1 16SM is the only one with an Active production status recorded. Neither part has any benchmark scores, wins, or nearest rivals in the database, so all comparisons rely on specification data rather than measured performance.