AMD Instinct MI355X vs NVIDIA N1X 48SM Comparison

Head-to-Head Benchmarks

The recorded database contains no head-to-head benchmark entries for the AMD Instinct MI355X and the NVIDIA N1X 48SM. Both parts have an average benchmark score of zero, and neither has any benchmark results listed. The wins tally is zero for both sides. This means the comparison must be built entirely from specification-level data and architectural analysis rather than direct performance measurements.

What the data does show is a clear separation in raw compute capabilities. The AMD Instinct MI355X delivers 78.64 TFLOPS of FP32 throughput, while the NVIDIA N1X 48SM delivers 28.83 TFLOPS. That puts the AMD part at roughly 2.73 times the FP32 throughput of the NVIDIA part. In FP16, both maintain a 1:1 ratio with their FP32 numbers, so the same 78.64 versus 28.83 TFLOPS spread applies. Texture rate tells a similar story: the MI355X reaches 2,457.6 GTexel/s versus 900.9 GTexel/s for the N1X 48SM, a factor of about 2.73 as well.

The pixel rate comparison is inverted, though. The NVIDIA N1X 48SM has a pixel rate of 112.6 GPixel/s, while the AMD part shows 0 MPixel/s. That zero is critical: the MI355X has no ROPs listed, meaning it is not designed for rasterization output at all. The N1X 48SM has 48 ROPs and a functional display pipeline with one HDMI output. For any workload that requires drawing to a framebuffer or driving a display, the NVIDIA part is the only one that can do it.

Memory bandwidth is another major divide. The MI355X uses 288 GB of HBM3e across an 8192-bit bus, producing 8.19 TB/s of bandwidth. The N1X 48SM uses 128 GB of LPDDR5X across a 256-bit bus, producing 273.2 GB/s. The AMD part has exactly 30 times the raw bandwidth of the NVIDIA part. That difference is enormous and directly affects any memory-bound compute task, from large model inference to dense matrix operations.

Clock behavior also differs. The MI355X has a base clock of 1000 MHz and a boost of 2400 MHz. The N1X 48SM has a base of 741 MHz and a boost of 2346 MHz. While the boost clocks are close, the AMD part sustains a much higher base clock, which matters for prolonged compute loads that do not hit boost conditions. The memory clock on the MI355X is listed at 2000 MHz with 8 Gbps effective, while the N1X 48SM runs at 1067 MHz with 8.5 Gbps effective. The effective data rate is slightly higher on the NVIDIA part, but the bus width difference overwhelms that.

FAQ

Q: Which part has higher FP32 compute throughput?

A: The AMD Instinct MI355X delivers 78.64 TFLOPS of FP32, which is 2.73 times the 28.83 TFLOPS of the NVIDIA N1X 48SM.

Q: Can the AMD Instinct MI355X drive a display?

A: No. The MI355X has no display outputs and a pixel rate of 0 MPixel/s. The NVIDIA N1X 48SM has one HDMI output and a pixel rate of 112.6 GPixel/s.

Q: What memory type and bandwidth does each use?

A: The MI355X uses 288 GB of HBM3e over an 8192-bit bus with 8.19 TB/s bandwidth. The N1X 48SM uses 128 GB of LPDDR5X over a 256-bit bus with 273.2 GB/s bandwidth.

Q: How many shading units does each part have?

A: The MI355X has 16,384 shading units. The N1X 48SM has 6,144 shading units.

Q: Which part has ray tracing and tensor cores?

A: Only the NVIDIA N1X 48SM lists ray tracing cores (48) and tensor cores (192). The AMD MI355X has no RT core or tensor core count listed in the database.

Q: What is the process node for each chip?

A: The MI355X uses a 3 nm process from TSMC. The N1X 48SM uses a 5 nm process from TSMC.

Architecture Differences

The architectural split is fundamental. The AMD Instinct MI355X is built on CDNA 4.0, a compute-focused architecture designed for accelerators. It uses the MI350 256CU chip, which indicates 256 compute units. The NVIDIA N1X 48SM is built on Blackwell 2.0, specifically the GB20B chip, and belongs to the Blackwell IGP (N1x) generation. The name "48SM" refers to 48 streaming multiprocessors.

The process nodes differ: the AMD part is on TSMC 3 nm, while the NVIDIA part is on TSMC 5 nm. Die size reflects the different roles. The MI355X has a die size of 2380 mm², which is enormous and typical of a dedicated accelerator with massive memory interfaces. The N1X 48SM has a die size of 382 mm², much smaller and consistent with an integrated graphics processor. Transistor counts diverge similarly: the MI355X has 185,000 million transistors, while the N1X 48SM has an unknown count. The AMD part also lists a transistor density of 77.7M per mm².

Memory architecture is a major differentiator. The MI355X uses HBM3e with an 8192-bit bus, which is a stacked memory design that trades power and cost for extreme bandwidth. The N1X 48SM uses LPDDR5X with a 256-bit bus, a standard low-power memory interface. The MI355X has no ROPs, no pixel rate, and no display outputs. The N1X 48SM has 48 ROPs, 48 RT cores, 192 tensor cores, and one HDMI output.

The NVIDIA part includes specialized hardware for ray tracing and tensor operations, which are absent from the AMD specification sheet. The AMD part instead has a much larger shading unit count (16,384 versus 6,144) and TMU count (1,024 versus 384). Both parts list PCIe 5.0 x16 as the bus interface, and both use no power connectors, but the AMD part lists a TDP of 1400 W and a suggested PSU of 1800 W. The NVIDIA part has an unknown TDP and no suggested PSU.

Specification Differences

The following fields differ between the two parts:

• Chip: MI350 256CU versus GB20B
• Architecture: CDNA 4.0 versus Blackwell 2.0
• Generation: Instinct (MIx) versus Blackwell IGP (N1x)
• Process node: 3 nm versus 5 nm
• Die size: 2380 mm² versus 382 mm²
• Transistor count: 185,000 million versus unknown
• Base clock: 1000 MHz versus 741 MHz
• Boost clock: 2400 MHz versus 2346 MHz
• Memory clock: 2000 MHz (8 Gbps effective) versus 1067 MHz (8.5 Gbps effective)
• Memory size: 288 GB versus 128 GB
• Memory type: HBM3e versus LPDDR5X
• Memory bus width: 8192 bit versus 256 bit
• Memory bandwidth: 8.19 TB/s versus 273.2 GB/s
• Shading units: 16,384 versus 6,144
• TMUs: 1,024 versus 384
• ROPs: 0 versus 48
• RT cores: none listed versus 48
• Tensor cores: none listed versus 192
• Pixel rate: 0 MPixel/s versus 112.6 GPixel/s
• Texture rate: 2,457.6 GTexel/s versus 900.9 GTexel/s
• FP32: 78.64 TFLOPS versus 28.83 TFLOPS
• FP16: 78.64 TFLOPS versus 28.83 TFLOPS
• TDP: 1400 W versus unknown
• Slot width: OAM Module versus IGP
• Display outputs: No outputs versus 1x HDMI
• Dimensions: 102 mm length, 165 mm width versus none listed
• Release date: 2025-06-11 versus 2026-05-31
• Production status: not listed versus Active
• Predecessor: Radeon Instinct versus none listed

Where Each One Wins

The AMD Instinct MI355X wins decisively in raw compute throughput. Its FP32 and FP16 figures are 2.73 times higher than the NVIDIA part. Texture rate is also 2.73 times higher. Memory bandwidth is 30 times higher. For workloads that depend on massive parallel compute and streaming data, such as large-scale matrix multiplication, dense neural network training, or scientific simulation, the MI355X is the stronger choice on paper. The larger memory capacity (288 GB versus 128 GB) also allows larger datasets to reside on-chip without spilling to system memory.

The NVIDIA N1X 48SM wins in every area related to graphics output and specialized acceleration. It has a functional pixel pipeline with 48 ROPs and a pixel rate of 112.6 GPixel/s. It includes 48 ray tracing cores and 192 tensor cores, which the AMD part does not list. It has one HDMI output, so it can drive a display. The smaller die size (382 mm² versus 2380 mm²) and lower unknown TDP suggest it fits in power-constrained environments, though the database does not list a TDP for the NVIDIA part.

The NVIDIA part also has a higher effective memory data rate (8.5 Gbps versus 8 Gbps), though the bus width difference makes this irrelevant for aggregate bandwidth. The N1X 48SM has a production status of Active, while the MI355X has no production status listed. The release dates differ by nearly a year, with the MI355X dated 2025-06-11 and the N1X 48SM dated 2026-05-31.

The Verdict

The data describes two devices with almost no functional overlap. The AMD Instinct MI355X is a dedicated accelerator with extreme compute throughput, immense memory bandwidth, and no display capability. The NVIDIA N1X 48SM is an integrated graphics processor with a modest compute footprint, a functional raster pipeline, and display output.

Choose the MI355X for workloads that require maximum FP32 or FP16 throughput, very large memory pools, or extremely high bandwidth. The 78.64 TFLOPS compute and 8.19 TB/s bandwidth place it in a different category from the N1X 48SM's 28.83 TFLOPS and 273.2 GB/s. The 288 GB memory capacity is more than double the NVIDIA part's 128 GB.

Choose the N1X 48SM for any task that needs graphics output, ray tracing, or tensor acceleration. The 48 ROPs, 48 RT cores, 192 tensor cores, and HDMI output are capabilities the MI355X does not have at all. The 112.6 GPixel/s pixel rate confirms it can handle rasterization work. The smaller die and unknown TDP also suggest a lower power envelope, though the database does not confirm that.

For pure compute density, the MI355X wins. For any display or graphics-related function, the N1X 48SM is the only option. The two parts are not competitors in the traditional sense; they serve different roles in a system. The benchmark data contains no direct comparison scores, so the verdict rests on the specification differences, which are stark and unambiguous.