AMD Instinct MI300X vs AMD Radeon RX 7900M Comparison

Head-to-Head Benchmarks

The only directly comparable benchmark in the database is Geekbench OpenCL, and the result is decisive. The AMD Instinct MI300X scores 317,994, while the AMD Radeon RX 7900M scores 129,499. The MI300X wins by 145.6%, a massive margin that reflects the fundamental differences in their design targets. In this single head-to-head test, the MI300X is 188,495 points ahead of the RX 7900M, which is more than the RX 7900M’s total score.

To contextualize the MI300X’s performance, its average benchmark score of 317,994 places it in the 100th percentile of all GPUs in the database. Its nearest rivals include the NVIDIA B200 (345,482, 8% higher), the NVIDIA H200 NVL (334,891, 5% higher), the NVIDIA L40S (295,763, 7.5% lower), and the NVIDIA RTX 6000 Ada Generation (287,237, 10.7% lower). The data shows that the MI300X is firmly in the top tier of compute accelerators, trading blows with NVIDIA’s flagship data center parts. It trails the B200 and H200 NVL by single-digit percentages but leads the L40S and RTX 6000 Ada by similar margins.

The RX 7900M, by contrast, sits at the 94th percentile, with an average benchmark score of 97,487 across its three recorded tests. Its nearest rivals are much closer in performance: the AMD Radeon Pro VII (97,131, 0.4% lower), the NVIDIA Quadro RTX 6000 (101,872, 4.3% higher), the AMD Radeon Instinct MI60 (92,466, 5.4% lower), and the NVIDIA RTX A4500 (91,671, 6.3% lower). This places the RX 7900M in a completely different performance class, roughly one-third the raw compute throughput of the MI300X in the OpenCL test.

The RX 7900M does have additional benchmark data beyond OpenCL: it scores 4,201 in 3DMark Steel Nomad DX12 and 158,760 in Geekbench Vulkan. The MI300X has no such entries, as its API support is listed as N/A for DirectX, OpenGL, and Vulkan. This is a crucial distinction: the MI300X is a compute-only accelerator, while the RX 7900M is a graphics-capable mobile part. The Vulkan score of 158,760 is notably higher than its OpenCL score, suggesting the RDNA 3.0 architecture performs better under graphics-oriented workloads.

Architecture Differences

The two GPUs share a manufacturer and a 5 nm TSMC process node, but their architectures diverge sharply. The MI300X uses CDNA 3.0 with the Aqua Vanjaram chip, while the RX 7900M uses RDNA 3.0 with the Navi 31 die and the Plum Bonito codename. This difference is not cosmetic: CDNA is AMD’s compute-optimized line, while RDNA targets graphics and gaming.

The transistor counts tell the story. The MI300X packs 153,000 million transistors on a 1017 mm² die, yielding a density of 150.4M transistors per mm². The RX 7900M has 57,700 million transistors on a 529 mm² die, with a lower density of 109.1M per mm². The MI300X has nearly three times the transistor budget and a die almost twice the size, which explains its enormous compute advantage. The MI300X’s density advantage also indicates a more aggressive packing of compute units.

Compute resources differ by an order of magnitude. The MI300X has 19,456 shading units and 1,216 texture mapping units, but zero ROPs. The RX 7900M has 4,608 shading units, 288 TMUs, and 192 ROPs. The MI300X’s lack of ROPs is telling: it is not designed to rasterize images, hence its zero pixel rate. The RX 7900M, by contrast, delivers 401.3 GPixel/s and 601.9 GTexel/s. The MI300X’s texture rate is 2,553.6 GTexel/s, over four times the RX 7900M’s, but this is a synthetic metric for a part that cannot output pixels.

Memory is another major differentiator. The MI300X uses 192 GB of HBM3 on an 8192-bit bus, delivering 5.32 TB/s of bandwidth. The RX 7900M has 16 GB of GDDR6 on a 256-bit bus, with 576.0 GB/s. The MI300X offers 12 times the capacity and over 9 times the bandwidth. The memory clock also differs: the MI300X runs at 1300 MHz (5.2 Gbps effective), while the RX 7900M runs at 2250 MHz (18 Gbps effective). The RX 7900M’s faster clock cannot compensate for its narrow bus.

Clock speeds are closer than expected. The MI300X has a base clock of 1000 MHz and a boost of 2100 MHz; the RX 7900M has a base of 1825 MHz and a boost of 2090 MHz. The MI300X’s base clock is much lower, reflecting its massive die and power envelope, but its boost clock nearly matches the mobile part. Floating-point output confirms the hierarchy: the MI300X delivers 81.72 TFLOPS FP32 and 81.72 TFLOPS FP16 (1:1 ratio). The RX 7900M delivers 38.52 TFLOPS FP32 and 77.05 TFLOPS FP16 (2:1 ratio). The MI300X has 2.1 times the FP32 throughput, while the RX 7900M’s FP16 is nearly equal due to its packed math.

Power and physical design differ completely. The MI300X has a TDP of 750 W, requires a suggested PSU of 1150 W, and comes as an OAM Module with no power connectors and no display outputs. The RX 7900M has a TDP of 180 W, is an IGP with no PSU recommendation, and has display outputs described as portable device dependent. The RX 7900M uses PCIe 4.0 x16, while the MI300X uses PCIe 5.0 x16.

The Verdict

The data dictates a clear split. The AMD Instinct MI300X is for compute-heavy data center workloads where raw throughput and memory capacity are paramount. Its 145.6% lead over the RX 7900M in OpenCL, its 100th percentile ranking, and its 192 GB of HBM3 make it a purpose-built accelerator for large-scale inference and training. The 750 W TDP and OAM form factor are irrelevant in a server context. The MI300X has no graphics APIs and no display outputs, so it cannot render images or drive monitors.

The AMD Radeon RX 7900M is for mobile workstations and laptops that need graphics capability alongside compute. Its 94th percentile ranking and Vulkan score of 158,760 show it is a capable graphics part. Its 180 W TDP and IGP form factor make it suitable for portable devices, and its display outputs are dependent on the host device. The RX 7900M’s ROPs, pixel rate, and DirectX 12 Ultimate support confirm its role as a rendering engine.

There is no scenario where these two compete directly. The MI300X wins every compute metric but cannot output video. The RX 7900M wins every graphics metric but has one-quarter the shading units and one-twelfth the memory. The MI300X’s FP32 of 81.72 TFLOPS versus 38.52 TFLOPS is a 2.1x gap, but the RX 7900M’s FP16 of 77.05 TFLOPS nearly matches the MI300X’s 81.72 TFLOPS, making the mobile part surprisingly competitive in mixed-precision workloads.

The RX 7900M’s nearest rivals include the NVIDIA RTX A4500 (6.3% lower), which is a professional mobile-class GPU, while the MI300X’s rivals are the B200 and H200 NVL, which are data center behemoths. The percentile gap (100th vs 94th) understates the compute divide because the RX 7900M’s average includes graphics tests. In the only shared benchmark, the MI300X is not merely faster; it is in a different performance universe.

Specification Differences

The following fields differ between the two parts:

• Architecture: CDNA 3.0 vs RDNA 3.0
• Chip: Aqua Vanjaram vs Navi 31
• Codename: None vs Plum Bonito
• Generation: Instinct (MIx) vs Navi Mobile (RX 7000M)
• Series: None vs Radeon RX 7000 series
• Transistors: 153,000 million vs 57,700 million
• Die Size: 1017 mm² vs 529 mm²
• Transistor Density: 150.4M / mm² vs 109.1M / mm²
• Base Clock: 1000 MHz vs 1825 MHz
• Memory Clock: 1300 MHz 5.2 Gbps effective vs 2250 MHz 18 Gbps effective
• Memory Size: 192 GB vs 16 GB
• Memory Type: HBM3 vs GDDR6
• Memory Bus: 8192 bit vs 256 bit
• Memory Bandwidth: 5.32 TB/s vs 576.0 GB/s
• Shading Units: 19456 vs 4608
• TMUs: 1216 vs 288
• ROPs: 0 vs 192
• RT Cores: None vs 72
• Pixel Rate: 0 MPixel/s vs 401.3 GPixel/s
• Texture Rate: 2,553.6 GTexel/s vs 601.9 GTexel/s
• FP32: 81.72 TFLOPS vs 38.52 TFLOPS
• FP16: 81.72 TFLOPS (1:1) vs 77.05 TFLOPS (2:1)
• TDP: 750 W vs 180 W
• Slot Width: OAM Module vs IGP
• Suggested PSU: 1150 W vs None
• Bus Interface: PCIe 5.0 x16 vs PCIe 4.0 x16
• Display Outputs: No outputs vs Portable Device Dependent
• DirectX: N/A vs 12 Ultimate (12_2)
• OpenGL: N/A vs 4.6
• Vulkan: N/A vs 1.4
• Production Status: None vs Active
• Release Date: 2023-12-05 vs 2023-10-18
• Predecessor: Radeon Instinct vs Polaris Mobile

FAQ

Q: Which GPU has higher FP32 performance?

A: The AMD Instinct MI300X delivers 81.72 TFLOPS FP32, which is 2.1 times the RX 7900M’s 38.52 TFLOPS. The MI300X also maintains a 1:1 FP16 ratio, while the RX 7900M uses a 2:1 ratio for its 77.05 TFLOPS FP16.

Q: How do they compare in the Geekbench OpenCL test?

A: The MI300X scores 317,994 versus 129,499 for the RX 7900M, a 145.6% difference. This is the only benchmark both GPUs share in the database.

Q: Can the MI300X output video to a display?

A: No. The MI300X has no display outputs and lists DirectX, OpenGL, and Vulkan as N/A. The RX 7900M has display outputs described as portable device dependent and supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4.

Q: What is the memory capacity difference?

A: The MI300X has 192 GB of HBM3 on an 8192-bit bus with 5.32 TB/s bandwidth. The RX 7900M has 16 GB of GDDR6 on a 256-bit bus with 576.0 GB/s. The MI300X has 12 times the capacity and over 9 times the bandwidth.

Q: Which GPU has more shading units?

A: The MI300X has 19,456 shading units, while the RX 7900M has 4,608. The MI300X also has 1,216 TMUs versus 288, but the RX 7900M has 192 ROPs while the MI300X has zero.

Q: What are the power requirements?

A: The MI300X has a 750 W TDP and requires a 1150 W suggested PSU. The RX 7900M has a 180 W TDP and has no PSU recommendation listed. The MI300X is an OAM Module, while the RX 7900M is an IGP.