AMD Instinct MI455X vs AMD Radeon RX 7400 OEM Comparison

Head-to-Head Benchmarks

The recorded data for both the AMD Instinct MI455X and the AMD Radeon RX 7400 OEM shows no overlapping benchmark entries in the database. The head-to-head comparison fields are empty, meaning there is no direct performance score for either part to compare side by side. The MI455X returns an average benchmark score of 0, while the RX 7400 OEM also returns an average benchmark score of 0. Both parts sit at the 50th percentile among all GPUs in the database, though this figure reflects their placement based on available data rather than any measured compute result.

The MI455X is an accelerator with a theoretical FP32 throughput of 157.3 TFLOPS, while the RX 7400 OEM offers 7.885 TFLOPS in FP32. That represents a ratio of roughly 20 to 1 in raw floating-point capability. The texture rate follows the same pattern: the MI455X reaches 2,457.6 GTexel/s versus 123.2 GTexel/s for the Radeon part. Pixel rate is a different story. The MI455X reports 0 MPixel/s, which reflects a design with no traditional raster output pipeline, while the RX 7400 OEM delivers 70.40 GPixel/s.

Memory bandwidth also diverges sharply. The MI455X provides 23.3 TB/s over a 24,576-bit bus using HBM4, while the RX 7400 OEM provides 172.8 GB/s over a 128-bit bus using GDDR6. The capacity difference is enormous: 432 GB versus 8 GB. Clock behavior differs as well. The MI455X runs at a base of 1000 MHz and a boost of 2400 MHz, whereas the RX 7400 OEM has a base of 330 MHz and a boost of 1100 MHz. The Radeon card actually has a lower boost clock by 1300 MHz, but its architecture is designed for graphics work, not raw compute density.

The absence of direct benchmark scores means the database cannot assign a head-to-head winner by measured performance. Instead, the theoretical specifications imply that the MI455X dominates in compute throughput, memory bandwidth, and memory capacity, while the RX 7400 OEM holds advantages in pixel throughput, display output, and power efficiency. The wins counters for both parts are set to 0.

Where Each One Wins

The MI455X wins in any workload that depends on massive parallel compute. Its 32,768 shading units, 1,024 TMUs, and 157.3 TFLOPS FP32 throughput position it for dense matrix math, large-scale simulation, and high-bandwidth data movement. The 432 GB of HBM4 memory with 23.3 TB/s bandwidth suits workloads where the entire model or dataset must stay resident on the accelerator. The 2 nm process node from TSMC with 320,000 million transistors on a 2,990 mm² die gives it a transistor density of 107.0M per mm², which supports the scale of the compute array.

The RX 7400 OEM wins in conventional graphics rendering. It has 64 ROPs, 28 ray accelerators, and a pixel rate of 70.40 GPixel/s. It supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the MI455X reports N/A for all three APIs. The Radeon part also has display outputs: 1x HDMI 2.1a and 3x DisplayPort 2.1. The MI455X has no display outputs at all. For any task that ends with pixels on a screen, the RX 7400 OEM is the only one of the two that can do the job.

Power behavior also splits the pair. The RX 7400 OEM runs at a TDP of 55 W with a suggested PSU of 250 W and a single 6-pin connector. The MI455X has a TDP of 2300 W and a suggested PSU of 2700 W. The Radeon card fits a single-slot form factor, while the MI455X uses an EAM Module form factor. The RX 7400 OEM is 167 mm long, which makes it suitable for small chassis. The MI455X has no listed dimensions, but its power and memory subsystem imply a much larger physical footprint.

The RX 7400 OEM also wins on connectivity compatibility. It uses PCIe 4.0 x8, which is broadly supported across modern motherboards. The MI455X uses PCIe 6.0 x16, which is a newer interface with less market penetration. For a system builder with an existing platform, the Radeon card is the more practical drop-in option.

Architecture Differences

The two products come from different architecture families. The MI455X is built on CDNA 5.0, AMD's compute-focused architecture, while the RX 7400 OEM is built on RDNA 3.0, the graphics-oriented architecture. The codenames tell the story: the MI455X uses the MI450 256CU chip, while the RX 7400 OEM uses Navi 33 with the codename Hotpink Bonefish.

The process nodes differ. The MI455X uses a 2 nm process at TSMC, while the RX 7400 OEM uses a 6 nm process at the same foundry. Transistor counts reflect the scale gap. The MI455X packs 320,000 million transistors on a 2,990 mm² die, which results in 107.0M transistors per mm². The RX 7400 OEM has 13,300 million transistors on a 204 mm² die, which gives 65.2M transistors per mm². The MI455X is not just larger, it is also denser.

Memory architecture is fundamentally different. The MI455X uses HBM4 with a 24,576-bit bus width and 7.6 Gbps effective memory speed, producing 23.3 TB/s of bandwidth. The RX 7400 OEM uses GDDR6 with a 128-bit bus and 10.8 Gbps effective speed, producing 172.8 GB/s. The MI455X has 432 GB of memory, which is 54 times the capacity of the RX 7400 OEM.

The compute arrays differ in composition. The MI455X has 32,768 shading units, 1,024 TMUs, and 0 ROPs. The RX 7400 OEM has 1,792 shading units, 112 TMUs, and 64 ROPs. The MI455X has no ray tracing cores listed, while the RX 7400 OEM includes 28 ray accelerators. Neither part lists tensor cores.

API support marks another divide. The MI455X reports N/A for DirectX, OpenGL, and Vulkan, which indicates it does not expose standard graphics APIs. The RX 7400 OEM supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The FP16 rates are identical to each part's FP32 rate, with both listed as 1:1 ratio, so neither part uses a packed FP16 path.

Clock behavior also differs. The MI455X has a 1000 MHz base clock and a 2400 MHz boost clock. The RX 7400 OEM has a 330 MHz base clock and a 1100 MHz boost clock. The memory clocks are listed as 1900 MHz (7.6 Gbps effective) for the MI455X and 1350 MHz (10.8 Gbps effective) for the RX 7400 OEM.

FAQ

Q: Which GPU has higher raw compute throughput?

A: The MI455X delivers 157.3 TFLOPS FP32, while the RX 7400 OEM delivers 7.885 TFLOPS FP32. The MI455X is roughly 20 times faster in theoretical floating-point performance.

Q: Can the MI455X output video to a display?

A: No. The MI455X lists no display outputs and reports N/A for DirectX, OpenGL, and Vulkan support. The RX 7400 OEM has 1x HDMI 2.1a and 3x DisplayPort 2.1 outputs.

Q: Which GPU uses more power?

A: The MI455X has a TDP of 2300 W with a suggested PSU of 2700 W. The RX 7400 OEM has a TDP of 55 W with a suggested PSU of 250 W.

Q: What memory types do the two GPUs use?

A: The MI455X uses 432 GB of HBM4 with a 24,576-bit bus and 23.3 TB/s bandwidth. The RX 7400 OEM uses 8 GB of GDDR6 with a 128-bit bus and 172.8 GB/s bandwidth.

Q: Which GPU supports ray tracing?

A: The RX 7400 OEM includes 28 ray accelerators. The MI455X does not list ray tracing cores.

Q: What process nodes are used?

A: The MI455X is built on a 2 nm TSMC process, while the RX 7400 OEM is built on a 6 nm TSMC process.

Specification Differences

The two GPUs differ across nearly every listed specification.

• Architecture: CDNA 5.0 for the MI455X, RDNA 3.0 for the RX 7400 OEM
• Chip: MI450 256CU versus Navi 33
• Codename: none listed for the MI455X, Hotpink Bonefish for the RX 7400 OEM
• Process node: 2 nm versus 6 nm, both TSMC
• Transistors: 320,000 million versus 13,300 million
• Die size: 2990 mm² versus 204 mm²
• Transistor density: 107.0M per mm² versus 65.2M per mm²
• Base clock: 1000 MHz versus 330 MHz
• Boost clock: 2400 MHz versus 1100 MHz
• Memory clock: 1900 MHz (7.6 Gbps effective) versus 1350 MHz (10.8 Gbps effective)
• Memory size: 432 GB versus 8 GB
• Memory type: HBM4 versus GDDR6
• Memory bus: 24,576 bit versus 128 bit
• Memory bandwidth: 23.3 TB/s versus 172.8 GB/s
• Shading units: 32,768 versus 1,792
• TMUs: 1,024 versus 112
• ROPs: 0 versus 64
• Ray accelerators: not listed versus 28
• Pixel rate: 0 MPixel/s versus 70.40 GPixel/s
• Texture rate: 2,457.6 GTexel/s versus 123.2 GTexel/s
• FP32: 157.3 TFLOPS versus 7.885 TFLOPS
• FP16: 157.3 TFLOPS (1:1) versus 7.885 TFLOPS (1:1)
• TDP: 2300 W versus 55 W
• Slot width: EAM Module versus Single-slot
• Power connectors: None versus 1x 6-pin
• Suggested PSU: 2700 W versus 250 W
• Bus interface: PCIe 6.0 x16 versus PCIe 4.0 x8
• Display outputs: No outputs versus 1x HDMI 2.1a and 3x DisplayPort 2.1
• DirectX: N/A versus 12 Ultimate (12_2)
• OpenGL: N/A versus 4.6
• Vulkan: N/A versus 1.4
• Length: not listed versus 167 mm (6.6 inches)
• Release date: 2026-07-22 versus 2025-08-07
• Predecessor: Radeon Instinct versus Navi II
• Successor: none listed versus Navi IV
• Series: none listed versus Radeon RX 7000 series
• Generation: Instinct (MIx) versus Navi III (RX 7000)