AMD Instinct MI308X vs NVIDIA GeForce RTX 4080 Max-Q Comparison

Where Each One Wins

The AMD Instinct MI308X and NVIDIA GeForce RTX 4080 Max-Q occupy entirely different corners of the GPU landscape, and the recorded data reflects that split clearly. The MI308X is built for massive parallel throughput and memory capacity, while the RTX 4080 Max-Q is a low-power mobile part with full API support.

In raw compute throughput, the MI308X wins decisively. Its FP32 output is 81.72 TFLOPS against 20.04 TFLOPS for the RTX 4080 Max-Q. That is a 4x advantage in single-precision compute. The FP16 figures mirror this exactly, with the MI308X again at 81.72 TFLOPS and the RTX 4080 Max-Q at 20.04 TFLOPS, both at a 1:1 ratio. The MI308X clearly targets compute workloads where raw floating-point volume is the primary metric.

Memory capacity and bandwidth tell the same story. The MI308X carries 192 GB of HBM3 on an 8192-bit bus, delivering 5.32 TB/s of bandwidth. The RTX 4080 Max-Q has 12 GB of GDDR6 on a 192-bit bus with 432.0 GB/s. The MI308X offers 16 times the memory capacity and over 12 times the bandwidth. For workloads that fit in GPU memory, such as large model inference or scientific simulation, the MI308X has an enormous practical advantage.

The RTX 4080 Max-Q wins in areas that require a conventional graphics pipeline. It has 80 ROPs and a pixel rate of 108.0 GPixel/s, while the MI308X reports 0 MPixel/s and no ROP count in the database. The MI308X also lists no display outputs, while the RTX 4080 Max-Q has outputs that are portable device dependent. The NVIDIA part supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI308X lists N/A for all three APIs. Any workload needing rasterization, ray tracing, or a display output belongs to the RTX 4080 Max-Q.

Power envelopes diverge sharply. The MI308X has a 750 W TDP and a suggested PSU of 1150 W. The RTX 4080 Max-Q draws only 60 W. That is a 690 W difference in thermal design power, making the RTX 4080 Max-Q suitable for systems where heat and power budgets are constrained. The MI308X is an OAM module with no power connectors listed, while the RTX 4080 Max-Q is an IGP-class part with no power connectors either, but its power draw is a fraction of the AMD accelerator.

Architecture Differences

The two chips come from different architectural lineages. The MI308X uses CDNA 3.0, AMD's compute-focused design, implemented on the Aqua Vanjaram chip. The RTX 4080 Max-Q uses Ada Lovelace, NVIDIA's graphics architecture, built around the AD104 chip. Both are fabricated by TSMC on a 5 nm process, but the similarity ends there.

Transistor counts differ by a wide margin. The MI308X has 153,000 million transistors on a 1017 mm² die, giving a transistor density of 150.4M per mm². The RTX 4080 Max-Q has 35,800 million transistors on a 294 mm² die, for a density of 121.8M per mm². The MI308X packs over four times as many transistors onto a die that is more than three times larger. The density difference suggests the MI308X uses a more compact design, likely due to the regularity of compute arrays versus the mixed-function blocks in a graphics processor.

The MI308X has 19,456 shading units and 1,216 TMUs, with no ROP count listed. The RTX 4080 Max-Q has 7,424 shading units, 232 TMUs, and 80 ROPs. The NVIDIA part also includes 58 ray tracing cores and 232 tensor cores. The MI308X lists no RT or tensor core counts. Texture rate favors the AMD part at 2,553.6 GTexel/s versus 313.2 GTexel/s, a direct consequence of the higher shader and TMU counts. Pixel rate favors NVIDIA at 108.0 GPixel/s, since the MI308X reports zero.

Memory subsystems are fundamentally different. The MI308X uses HBM3 with a 5.32 TB/s bandwidth on an 8192-bit bus and a memory clock of 1300 MHz with 5.2 Gbps effective. The RTX 4080 Max-Q uses GDDR6 with 432.0 GB/s on a 192-bit bus and a memory clock of 2250 MHz with 18 Gbps effective. The bus width difference is extreme, 8192 bits versus 192 bits, which explains the bandwidth gap despite the NVIDIA part's higher effective memory clock.

Bus interfaces also differ. The MI308X uses PCIe 5.0 x16, while the RTX 4080 Max-Q uses PCIe 4.0 x16. The MI308X has no display outputs and no API support listed. The RTX 4080 Max-Q has portable device dependent outputs and full API coverage. The production status of the MI308X is not listed, while the RTX 4080 Max-Q is marked active. Release dates also differ: the MI308X launched on December 5, 2023, and the RTX 4080 Max-Q on January 2, 2023.

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark entries for these two parts. The wins and loss counts are both zero. This absence is itself informative: the two GPUs are not measured against each other in standard benchmark suites because they serve different purposes. The MI308X has no benchmark scores recorded and sits at the 50th percentile among all GPUs, with an average benchmark score of zero. The RTX 4080 Max-Q is in the same position, also at the 50th percentile with a zero average score.

Without direct benchmark results, the specification data provides the only basis for comparison. The FP32 compute gap is the largest single difference. At 81.72 TFLOPS, the MI308X is 61.68 TFLOPS ahead of the RTX 4080 Max-Q. In relative terms, the MI308X delivers about 4.08 times the FP32 throughput. The same ratio applies to FP16, since both parts run at a 1:1 ratio.

Memory bandwidth is the second major gap. The MI308X at 5.32 TB/s exceeds the RTX 4080 Max-Q at 432.0 GB/s by roughly 12.3 times. Capacity is 16 times larger on the MI308X. Texture rate favors the MI308X by 8.16 times, while pixel rate favors the RTX 4080 Max-Q, which has 80 ROPs versus none reported for the AMD part.

Power efficiency is the one metric where the RTX 4080 Max-Q leads. At 60 W, the NVIDIA part draws 12.5 times less power than the MI308X at 750 W. The RTX 4080 Max-Q achieves 0.334 TFLOPS per watt in FP32. The MI308X achieves 0.109 TFLOPS per watt. The NVIDIA part is roughly three times more efficient in raw FP32 per watt, though this comparison ignores the massive memory bandwidth and capacity that the MI308X provides.

FAQ

Q: Which GPU has higher FP32 compute performance?

A: The AMD Instinct MI308X delivers 81.72 TFLOPS in FP32, compared to 20.04 TFLOPS for the NVIDIA GeForce RTX 4080 Max-Q.

Q: How much memory does each GPU have?

A: The MI308X has 192 GB of HBM3 memory on an 8192-bit bus. The RTX 4080 Max-Q has 12 GB of GDDR6 memory on a 192-bit bus.

Q: Which GPU supports ray tracing?

A: The RTX 4080 Max-Q has 58 ray tracing cores and supports DirectX 12 Ultimate (12_2). The MI308X lists no ray tracing cores and no API support in the database.

Q: What is the power draw of each GPU?

A: The MI308X has a TDP of 750 W with a suggested PSU of 1150 W. The RTX 4080 Max-Q has a TDP of 60 W.

Q: Can the MI308X output to a display?

A: No. The MI308X lists no display outputs. The RTX 4080 Max-Q has display outputs described as portable device dependent.

Q: What are the memory bandwidth figures?

A: The MI308X provides 5.32 TB/s of bandwidth. The RTX 4080 Max-Q provides 432.0 GB/s.

Specification Differences

Process node: Both use TSMC 5 nm, so this is not a differentiator.

Transistors: The MI308X has 153,000 million transistors. The RTX 4080 Max-Q has 35,800 million.

Die size: The MI308X measures 1017 mm². The RTX 4080 Max-Q measures 294 mm².

Transistor density: The MI308X reaches 150.4M per mm². The RTX 4080 Max-Q reaches 121.8M per mm².

Base clock: The MI308X runs at 1000 MHz. The RTX 4080 Max-Q runs at 795 MHz.

Boost clock: The MI308X boosts to 2100 MHz. The RTX 4080 Max-Q boosts to 1350 MHz.

Memory clock: The MI308X uses 1300 MHz with 5.2 Gbps effective. The RTX 4080 Max-Q uses 2250 MHz with 18 Gbps effective.

Memory size: 192 GB on the MI308X versus 12 GB on the RTX 4080 Max-Q.

Memory type: HBM3 on the MI308X versus GDDR6 on the RTX 4080 Max-Q.

Memory bus width: 8192 bit versus 192 bit.

Memory bandwidth: 5.32 TB/s versus 432.0 GB/s.

Shading units: 19,456 versus 7,424.

TMUs: 1,216 versus 232.

ROPs: None reported for the MI308X versus 80 for the RTX 4080 Max-Q.

Ray tracing cores: Not listed for the MI308X versus 58 for the RTX 4080 Max-Q.

Tensor cores: Not listed for the MI308X versus 232 for the RTX 4080 Max-Q.

Pixel rate: 0 MPixel/s versus 108.0 GPixel/s.

Texture rate: 2,553.6 GTexel/s versus 313.2 GTexel/s.

FP32 and FP16: 81.72 TFLOPS on the MI308X versus 20.04 TFLOPS on the RTX 4080 Max-Q.

TDP: 750 W versus 60 W.

Slot width: OAM Module versus IGP.

Bus interface: PCIe 5.0 x16 versus PCIe 4.0 x16.

Display outputs: None versus portable device dependent.

API support: The MI308X lists N/A for DirectX, OpenGL, and Vulkan. The RTX 4080 Max-Q supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Release date: The MI308X launched December 5, 2023. The RTX 4080 Max-Q launched January 2, 2023.

Predecessor: The MI308X follows Radeon Instinct. The RTX 4080 Max-Q follows GeForce 30 Mobile.

Successor: The MI308X has none listed. The RTX 4080 Max-Q is succeeded by GeForce 50 Mobile.

Production status: Not listed for the MI308X. Active for the RTX 4080 Max-Q.