AMD Instinct MI355X vs NVIDIA GeForce RTX 4080 Max-Q Comparison

The AMD Instinct MI355X and NVIDIA GeForce RTX 4080 Max-Q occupy entirely different corners of the hardware spectrum. One is a massive accelerator module built for dense compute workloads, and the other is a power-restricted mobile graphics processor. The recorded data shows a complete divergence in purpose, architecture, and physical design. This analysis compares the two strictly from the documented specifications and measured characteristics in the database.

Head-to-Head Benchmarks

The database contains no direct benchmark scores for either product. Both entries record an average benchmark score of zero, and the head-to-head benchmark array is empty. The wins counter shows zero for both the AMD Instinct MI355X and the NVIDIA GeForce RTX 4080 Max-Q. Without recorded performance measurements, direct comparisons rely entirely on the theoretical throughput figures and hardware specifications.

The FP32 floating-point performance shows the clearest separation. The AMD Instinct MI355X delivers 78.64 TFLOPS of FP32 compute. The NVIDIA GeForce RTX 4080 Max-Q achieves 20.04 TFLOPS. That places the AMD part at roughly 3.9 times the raw FP32 throughput of the NVIDIA mobile chip. The FP16 figures mirror this exactly, with both cards running FP16 at a 1:1 ratio to their FP32 numbers. The MI355X lists 78.64 TFLOPS FP16, and the RTX 4080 Max-Q lists 20.04 TFLOPS FP16.

Texture processing follows the same trend. The AMD accelerator reaches 2,457.6 GTexel/s, while the NVIDIA part manages 313.2 GTexel/s. The pixel rate comparison flips dramatically in the other direction. The MI355X records 0 MPixel/s with zero ROPs, because it has no traditional rasterization pipeline. The RTX 4080 Max-Q delivers 108.0 GPixel/s using its 80 ROPs. This single metric highlights the fundamental divide: the MI355X is not designed to draw frames, and the RTX 4080 Max-Q is a rasterization-capable graphics processor.

Memory bandwidth shows another massive gap. The MI355X uses 8.19 TB/s of bandwidth across an 8192-bit bus. The RTX 4080 Max-Q provides 432.0 GB/s over a 192-bit bus. That works out to nearly 19 times more memory bandwidth for the AMD part. The memory capacity difference is even larger: 288 GB of HBM3e on the MI355X versus 12 GB of GDDR6 on the RTX 4080 Max-Q.

Clock speeds tell a different story. The MI355X runs a 1000 MHz base clock and a 2400 MHz boost clock. The RTX 4080 Max-Q runs a 795 MHz base and a 1350 MHz boost. The AMD chip is clocked higher, but it also consumes far more power. The MI355X has a 1400 W TDP, and the RTX 4080 Max-Q has a 60 W TDP. Efficiency calculations are not explicitly listed in the database, but the raw numbers show the NVIDIA part operates at a fraction of the power envelope.

The Verdict

The data points to a clear split by workload. The AMD Instinct MI355X is an accelerator with no display outputs, no rasterization hardware, and a zero pixel rate. It is built for computation that scales with raw FP32, FP16, and memory bandwidth. The RTX 4080 Max-Q is a mobile GPU with 80 ROPs, 58 ray tracing cores, 232 tensor cores, and support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4. The MI355X lists no API support at all, with DirectX, OpenGL, and Vulkan all marked as N/A.

Anyone choosing between these two should look at the physical and power requirements first. The MI355X is an OAM module with no power connectors, a suggested PSU of 1800 W, and dimensions of 102 mm by 165 mm. The RTX 4080 Max-Q is an IGP part with no external power connectors, a 60 W TDP, and no listed dimensions. The MI355X requires a server platform designed for OAM modules and massive power delivery. The RTX 4080 Max-Q fits into a laptop chassis.

The benchmark data cannot rank one as superior because they target different domains. The MI355X offers 3.9 times the FP32 throughput, 19 times the memory bandwidth, and 24 times the memory capacity. The RTX 4080 Max-Q offers rasterization, ray tracing, tensor cores, display output, and a 1400 W lower power draw. The verdict from the recorded specifications is that the MI355X is a compute accelerator and the RTX 4080 Max-Q is a graphics processor.

Architecture Differences

The MI355X uses the MI350 256CU chip built on CDNA 4.0 architecture. The RTX 4080 Max-Q uses the AD104 chip built on Ada Lovelace architecture. The manufacturing process differs: the MI355X is fabricated on a 3 nm node at TSMC, and the RTX 4080 Max-Q is fabricated on a 5 nm node at TSMC. The transistor counts reflect the scale difference. The MI355X contains 185,000 million transistors on a 2380 mm² die, giving a density of 77.7 million transistors per square millimeter. The RTX 4080 Max-Q contains 35,800 million transistors on a 294 mm² die, giving a density of 121.8 million transistors per square millimeter.

The shader configuration diverges sharply. The MI355X has 16,384 shading units and 1,024 texture mapping units, but zero ROPs and no dedicated ray tracing or tensor cores listed. The RTX 4080 Max-Q has 7,424 shading units, 232 TMUs, 80 ROPs, 58 ray tracing cores, and 232 tensor cores. The absence of ROPs and ray tracing hardware on the MI355X confirms its non-rendering focus. The presence of 232 tensor cores and 58 RT cores on the NVIDIA part supports its use in graphics, ray tracing, and AI inference workloads.

Memory architecture is also fundamentally different. The MI355X uses HBM3e memory across an 8192-bit bus with 8.19 TB/s bandwidth. The RTX 4080 Max-Q uses GDDR6 across a 192-bit bus with 432.0 GB/s bandwidth. The memory clock differs as well: the MI355X runs at 2000 MHz with 8 Gbps effective, and the RTX 4080 Max-Q runs at 2250 MHz with 18 Gbps effective. The higher effective data rate on the NVIDIA memory does not compensate for the much narrower bus.

The generation labels place them in separate product lines. The MI355X belongs to the Instinct (MIx) generation under the Radeon Instinct predecessor. The RTX 4080 Max-Q belongs to the GeForce 40 Mobile generation, succeeding the GeForce 30 Mobile and preceding the GeForce 50 Mobile. The MI355X lists no successor.

Specification Differences

The process node differs: 3 nm for the MI355X versus 5 nm for the RTX 4080 Max-Q. The die size differs: 2380 mm² for the MI355X versus 294 mm² for the RTX 4080 Max-Q. Transistor density is higher on the NVIDIA chip at 121.8 million per square millimeter versus 77.7 million per square millimeter on the AMD chip.

Base clocks are 1000 MHz for the MI355X and 795 MHz for the RTX 4080 Max-Q. Boost clocks are 2400 MHz for the MI355X and 1350 MHz for the RTX 4080 Max-Q. Memory type, capacity, bus width, and bandwidth all differ: HBM3e 288 GB, 8192-bit, 8.19 TB/s versus GDDR6 12 GB, 192-bit, 432.0 GB/s.

Shading units number 16,384 for the MI355X and 7,424 for the RTX 4080 Max-Q. TMUs number 1,024 versus 232. ROPs are 0 versus 80. The RTX 4080 Max-Q has 58 ray tracing cores and 232 tensor cores; the MI355X lists none of either. Pixel rate is 0 MPixel/s versus 108.0 GPixel/s. Texture rate is 2,457.6 GTexel/s versus 313.2 GTexel/s.

FP32 performance is 78.64 TFLOPS versus 20.04 TFLOPS. FP16 performance matches those figures for both. TDP is 1400 W versus 60 W. The slot width is OAM Module versus IGP. The suggested PSU is 1800 W for the MI355X, and no suggested PSU is listed for the RTX 4080 Max-Q.

The bus interface differs: PCIe 5.0 x16 for the MI355X and PCIe 4.0 x16 for the RTX 4080 Max-Q. Display outputs are listed as none for the MI355X and portable device dependent for the RTX 4080 Max-Q. API support is N/A for all three categories on the MI355X, while the RTX 4080 Max-Q supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4.

Dimensions are only listed for the MI355X: 102 mm length and 165 mm width. The RTX 4080 Max-Q lists no dimensions because it is an integrated mobile part. Release dates differ: the MI355X released on June 11, 2025, and the RTX 4080 Max-Q released on January 2, 2023. The production status is listed as active for the RTX 4080 Max-Q, and no production status is listed for the MI355X.

FAQ

Q: Which GPU has higher FP32 performance?

A: The AMD Instinct MI355X records 78.64 TFLOPS of FP32 compute, while the NVIDIA GeForce RTX 4080 Max-Q records 20.04 TFLOPS. The AMD part delivers roughly 3.9 times the FP32 throughput.

Q: Does the AMD Instinct MI355X support display outputs?

A: No, the database lists display outputs as none for the MI355X. It also shows zero ROPs and a pixel rate of 0 MPixel/s, indicating no rasterization output capability.

Q: What memory configurations do these two parts use?

A: The MI355X uses 288 GB of HBM3e on an 8192-bit bus with 8.19 TB/s bandwidth. The RTX 4080 Max-Q uses 12 GB of GDDR6 on a 192-bit bus with 432.0 GB/s bandwidth.

Q: Does the RTX 4080 Max-Q have ray tracing cores?

A: Yes, the RTX 4080 Max-Q lists 58 ray tracing cores and 232 tensor cores. The MI355X lists no ray tracing cores and no tensor cores.

Q: What is the power consumption difference?

A: The MI355X has a TDP of 1400 W and a suggested PSU of 1800 W. The RTX 4080 Max-Q has a TDP of 60 W and lists no suggested PSU.

Q: Which API standards does each part support?

A: The RTX 4080 Max-Q supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4. The MI355X lists DirectX, OpenGL, and Vulkan all as N/A.