AMD Instinct MI455X vs AMD Radeon 740M Comparison

Head-to-Head Benchmarks

The recorded data shows a stark contrast between these two AMD parts, but direct comparison is complicated by a fundamental gap: the AMD Instinct MI455X has no recorded benchmark scores in the database. Its average benchmark score is 0, and its percentile ranking sits at 50. The AMD Radeon 740M, by contrast, has two recorded scores: 10,172 in Geekbench OpenCL and 15,568 in Geekbench Vulkan. Its average benchmark score is 12,870, placing it at the 53rd percentile of all GPUs.

Because the MI455X lacks benchmark entries, there are no head-to-head test results, and the wins counter shows 0 for both units. The only numerical performance comparisons available involve the Radeon 740M and its nearest rivals. The database places the FirePro W5100 within 0.2% of the 740M's average score, the Radeon Pro 455 within 0.3%, and the GeForce GTX 590 also within 0.3%. The Radeon RX 580 sits 0.4% behind the 740M. These deltas are tiny, indicating that the 740M clusters tightly with older discrete GPUs in compute workloads.

The absence of MI455X benchmark data means the database cannot quantify its compute performance relative to the 740M. The MI455X's theoretical peak rates, however, are recorded: 157.3 TFLOPS for FP32 and the same for FP16 (1:1 ratio). The 740M delivers 2.867 TFLOPS for both FP32 and FP16. That theoretical FP32 ratio is roughly 55 to 1 in the MI455X's favor, though such a comparison is purely speculative because no measured scores exist for the MI455X.

Architecture Differences

The MI455X uses the CDNA 5.0 architecture, while the 740M uses RDNA 3.0. These are distinct design families with different priorities. CDNA targets compute acceleration, and RDNA targets graphics and general-purpose workloads. The MI455X's chip is designated MI450 256CU, and the 740M's chip is Phoenix2.

The manufacturing processes differ significantly. The MI455X is built on a 2 nm node at TSMC, whereas the 740M uses a 4 nm TSMC node. Transistor counts reflect the scale gap: the MI455X packs 320,000 million transistors on a 2990 mm² die, giving a density of 107.0 million per mm². The 740M contains 20,900 million transistors on a 137 mm² die, with a higher density of 152.6 million per mm². The MI455X is a massive compute accelerator, and the 740M is a compact integrated graphics processor.

Clock behavior also diverges. The MI455X has a base clock of 1000 MHz and a boost clock of 2400 MHz. The 740M starts lower at 800 MHz but boosts higher to 2800 MHz. Memory clocks differ entirely: the MI455X runs memory at 1900 MHz with 7.6 Gbps effective, while the 740M uses system shared memory with no dedicated clock figure. The MI455X's memory subsystem is HBM4 with 432 GB capacity, a 24576-bit bus, and 23.3 TB/s bandwidth. The 740M's memory is system shared, with bus width and bandwidth listed as system dependent.

Compute resources are vastly different. The MI455X has 32,768 shading units, 1,024 texture mapping units, and zero ROPs. The 740M has 256 shading units, 16 TMUs, and 8 ROPs. The MI455X reports no ray tracing cores, while the 740M has 4 RT cores. Neither part lists tensor cores. The MI455X's pixel rate is 0 MPixel/s, reflecting its compute-only design, while the 740M achieves 22.40 GPixel/s. Texture rates are 2,457.6 GTexel/s for the MI455X versus 44.80 GTexel/s for the 740M.

API support separates them sharply. The MI455X reports N/A for DirectX, OpenGL, and Vulkan, indicating it is not designed for graphics APIs. The 740M supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI455X has no display outputs, while the 740M's outputs are motherboard dependent, consistent with an integrated graphics solution.

Where Each One Wins

The Radeon 740M wins in every measurable benchmark category because the MI455X has no recorded scores. The 740M's Geekbench Vulkan score of 15,568 exceeds its OpenCL score of 10,172 by roughly 53%, indicating stronger performance in graphics-oriented compute workloads. Its average score of 12,870 places it above the 53rd percentile of all GPUs, edging past the 50th percentile of the MI455X.

The MI455X wins on raw specification sheets. Its 157.3 TFLOPS FP32 throughput dwarfs the 740M's 2.867 TFLOPS. Its 23.3 TB/s memory bandwidth versus system dependent bandwidth for the 740M makes it suitable for data-intensive workloads. Its 432 GB HBM4 memory capacity has no equivalent in the 740M, which relies on shared system memory. The MI455X's 32,768 shading units and 1,024 TMUs are orders of magnitude beyond the 740M's 256 and 16, respectively.

The 740M holds advantages in practical graphics contexts. It has 8 ROPs, enabling 22.40 GPixel/s fill rate, whereas the MI455X has 0 ROPs and 0 MPixel/s pixel rate. The 740M supports modern graphics APIs and can drive displays through the motherboard. The MI455X has no display outputs and no API support, making it unsuitable for rendering or interactive workloads.

The MI455X also has no production status listed, while the 740M is marked active. The MI455X's release date is July 22, 2026, and the 740M's is January 30, 2024. The MI455X's predecessor is Radeon Instinct, and the 740M's predecessor is Navi II IGP. The 740M has a successor, Navi III IGP, while the MI455X has none recorded.

Specification Differences

The two parts differ across nearly every specification field. Process node: 2 nm for the MI455X, 4 nm for the 740M. Transistors: 320,000 million versus 20,900 million. Die size: 2990 mm² versus 137 mm². Transistor density: 107.0M per mm² versus 152.6M per mm². Base clock: 1000 MHz versus 800 MHz. Boost clock: 2400 MHz versus 2800 MHz. Memory clock: 1900 MHz (7.6 Gbps effective) versus system shared.

Memory capacity: 432 GB HBM4 versus system shared. Bus width: 24576 bit versus system shared. Bandwidth: 23.3 TB/s versus system dependent. Shading units: 32,768 versus 256. TMUs: 1,024 versus 16. ROPs: 0 versus 8. Ray tracing cores: none listed versus 4. Pixel rate: 0 MPixel/s versus 22.40 GPixel/s. Texture rate: 2,457.6 GTexel/s versus 44.80 GTexel/s. FP32: 157.3 TFLOPS versus 2.867 TFLOPS. FP16: 157.3 TFLOPS (1:1) versus 2.867 TFLOPS (1:1).

TDP: 2300 W for the MI455X, 45 W for the 740M. Slot width: EAM Module versus IGP. Power connectors: none for both. Suggested PSU: 2700 W for the MI455X, none listed for the 740M. Bus interface: PCIe 6.0 x16 versus PCIe 4.0 x8. Display outputs: none versus motherboard dependent. DirectX: N/A versus 12 Ultimate (12_2). OpenGL: N/A versus 4.6. Vulkan: N/A versus 1.4. Production status: none versus active. Release date: 2026-07-22 versus 2024-01-30. Predecessor: Radeon Instinct versus Navi II IGP. Successor: none versus Navi III IGP.

FAQ

Q: Which GPU has a higher boost clock?

A: The AMD Radeon 740M boosts to 2800 MHz, which is 400 MHz higher than the AMD Instinct MI455X's boost clock of 2400 MHz.

Q: Does the AMD Instinct MI455X support any graphics APIs?

A: No. The database records DirectX, OpenGL, and Vulkan as N/A for the MI455X. The Radeon 740M supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: What is the memory bandwidth difference?

A: The MI455X has 23.3 TB/s bandwidth from its 432 GB HBM4 memory on a 24576-bit bus. The 740M uses system shared memory, and its bandwidth is listed as system dependent.

Q: How do their benchmark scores compare?

A: The MI455X has no recorded benchmark scores, with an average score of 0. The 740M has scores of 10,172 in Geekbench OpenCL and 15,568 in Geekbench Vulkan, for an average of 12,870.

Q: Which GPU has more shading units?

A: The MI455X has 32,768 shading units. The 740M has 256 shading units, which is 128 times fewer.

Q: What are their transistor densities?

A: The MI455X has a density of 107.0 million transistors per mm² across 320,000 million transistors on a 2990 mm² die. The 740M has a higher density of 152.6 million per mm² across 20,900 million transistors on a 137 mm² die.

The Verdict

The data supports a clear split: the AMD Instinct MI455X is a compute accelerator with no graphics capability, and the AMD Radeon 740M is an integrated graphics processor with no compute accelerator pretensions. The MI455X's specifications indicate it targets workloads requiring massive FP32 and FP16 throughput, 432 GB of HBM4 memory, and 23.3 TB/s bandwidth. Its 2300 W TDP and 2700 W suggested PSU confirm it is a data-center part. Its lack of display outputs, APIs, and ROPs means it cannot render frames or output video.

The 740M, with 45 W TDP, 4 RT cores, and support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, is designed for graphics and general-purpose compute in a mobile or embedded context. Its benchmark scores show it performs slightly above the 50th percentile of all GPUs, landing at the 53rd percentile, and it stays within 0.4% of the Radeon RX 580's average score in the database.

Who should pick which depends entirely on workload. The MI455X is the only choice for compute-heavy tasks that need its 157.3 TFLOPS and 432 GB memory, provided the system can supply 2700 W. The 740M is the only choice for graphics output, API compatibility, or low-power operation at 45 W. There is no overlap in their capabilities, so the verdict is not about trade-offs but about matching the hardware to the task. The MI455X's lack of benchmark data means its real-world performance cannot be verified, only its theoretical specifications. The 740M's measured scores at least confirm its position relative to older discrete GPUs.