AMD Instinct MI455X vs AMD Radeon 8040S Comparison

AMD Instinct MI455X and AMD Radeon 8040S represent two entirely separate branches of AMD’s GPU lineup, one aimed at massive compute workloads and the other at integrated mobile graphics. The recorded data shows a stark contrast in nearly every measurable category, from architecture to memory configuration to benchmark presence. This analysis walks through the head-to-head comparisons, architectural differences, and practical use cases based solely on the database entries.

Head-to-Head Benchmarks

The database contains benchmark results only for the AMD Radeon 8040S. The AMD Instinct MI455X has no recorded benchmarks, no average score, and no nearest rivals listed. Its percentile versus all GPUs sits at 50, meaning it lands at the midpoint of the distribution, but this is not derived from any active test data. The Radeon 8040S, by contrast, holds a percentile of 17 and an average benchmark score of 2440.

For the Radeon 8040S, the individual PassMark tests show a clear pattern. The strongest result appears in passmark_g3d with a score of 10578, which indicates the integrated part performs best in general 3D rendering tasks. The passmark_g2d score of 1052 shows a much lower result for 2D workloads. Compute performance lands at 5138 in passmark_gpu_compute, roughly half the 3D score. The older DirectX tests reveal a mixed picture: passmark_directx_9 scores 134, passmark_directx_11 scores 80, while passmark_directx_10 and passmark_directx_12 each score 48 and 47 respectively. These numbers suggest the 8040S handles legacy DirectX 9 workloads relatively well but struggles with more modern DirectX 12 paths, likely due to its integrated nature and shared system resources.

The nearest rivals for the 8040S, according to the database, are all low-end parts. The NVIDIA GeForce 710M posts an average score of 2433, which is 0.3 percent behind the 8040S. The Intel HD Graphics 610 scores 2425, 0.6 percent behind. The NVIDIA GeForce GT 710M scores 2422, 0.7 percent behind. The only rival that scores higher is the AMD Radeon RX 7400 with 2467, which beats the 8040S by 1.1 percent. These delta values are extremely small, placing the 8040S in a tightly clustered group of entry-level graphics solutions. The data indicates that the 8040S does not break away from its immediate competition; it sits within a single percentage point of all four listed rivals.

Since the MI455X has no benchmark entries, no direct score comparison can be made. The head-to-head benchmark array is empty, and the wins count is zero for both items. Any quantitative comparison between the two parts relies entirely on specification data rather than measured performance.

Architecture Differences

The architectural gap between these two GPUs is fundamental. The MI455X uses CDNA 5.0 architecture on a 2 nm process node from TSMC, built around the MI450 256CU chip. The Radeon 8040S uses RDNA 3.5 architecture on a 4 nm process node, also from TSMC, based on the Strix Halo chip. The process node difference alone indicates a significant generational and manufacturing gap, with the MI455X using a denser node.

The MI455X integrates 320,000 million transistors on a die size of 2990 mm², giving a transistor density of 107.0 million transistors per square millimeter. The Radeon 8040S has a die size of 308 mm², which is dramatically smaller, and its transistor count is listed as unknown in the database. The MI455X is a monolithic compute accelerator with an enormous physical footprint, while the 8040S is an integrated GPU (IGP) designed to fit within a mobile processor package.

Memory configuration differs completely. The MI455X carries 432 GB of HBM4 memory on a 24576-bit bus, delivering 23.3 TB/s of bandwidth. The memory clock is listed as 1900 MHz with 7.6 Gbps effective data rate. The 8040S uses system shared memory, meaning it has no dedicated VRAM. Its memory size, type, bus width, and bandwidth are all listed as system dependent. This is a crucial distinction: the MI455X has a massive, dedicated, high-bandwidth memory pool, while the 8040S borrows from the host system’s RAM and is limited by that system’s memory bandwidth.

Compute resources follow the same pattern. The MI455X features 32768 shading units, 1024 texture mapping units, and 0 ROPs. Its pixel rate is 0 MPixel/s, and its texture rate is 2457.6 GTexel/s. The 8040S has 1024 shading units, 64 TMUs, 32 ROPs, and 16 ray tracing cores. Its pixel rate is 89.60 GPixel/s, and its texture rate is 179.2 GTexel/s. The MI455X has 32 times more shading units and 16 times more TMUs, but the 8040S has a non-zero ROP count and ray tracing support. The MI455X’s zero ROP count reflects its compute-oriented design, where rasterization output is not a priority.

Clock speeds also differ substantially. The MI455X has a base clock of 1000 MHz and a boost clock of 2400 MHz. The 8040S has a base clock of 1295 MHz and a boost clock of 2800 MHz. Despite the higher clocks on the 8040S, the MI455X delivers far more raw throughput due to its massive shader count. The FP32 and FP16 performance for the MI455X is 157.3 TFLOPS in both cases, with a 1:1 ratio. The 8040S delivers 5.734 TFLOPS in both FP32 and FP16, also at a 1:1 ratio. The MI455X is roughly 27 times faster in raw floating-point throughput.

Power and physical requirements diverge sharply. The MI455X has a TDP of 2300 W and a suggested PSU of 2700 W. Its slot width is listed as an EAM Module, and it has no power connectors. The 8040S has a TDP of 55 W, no suggested PSU listed, and is classified as an IGP. The MI455X requires industrial-level power delivery and cooling, while the 8040S fits within the thermal envelope of a mobile processor. The bus interface also differs: the MI455X uses PCIe 6.0 x16, while the 8040S uses PCIe 5.0 x16. Display outputs are absent on the MI455X, while the 8040S’s outputs are listed as portable device dependent.

API support differs completely. The MI455X lists DirectX, OpenGL, and Vulkan as N/A, indicating it is not designed for standard graphics APIs. The 8040S supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. This confirms that the MI455X is a compute accelerator without a conventional graphics pipeline, while the 8040S is a full-featured graphics solution for consumer workloads.

Where Each One Wins

The MI455X wins in every raw compute category recorded in the database. Its FP32 throughput of 157.3 TFLOPS dwarfs the 8040S’s 5.734 TFLOPS. Its texture rate of 2457.6 GTexel/s is more than 13 times higher than the 8040S’s 179.2 GTexel/s. Its memory bandwidth of 23.3 TB/s provides a scale of data movement that the 8040S cannot approach, especially given the 8040S relies on system shared memory with system-dependent bandwidth. The MI455X is also built on a newer 2 nm process, has a much larger die, and supports HBM4 memory, all of which point to workloads involving massive parallel computation, large model training, or scientific simulation.

The Radeon 8040S wins in areas that the MI455X does not address at all. It has 32 ROPs and a pixel rate of 89.60 GPixel/s, while the MI455X has 0 ROPs and a 0 MPixel/s pixel rate. The 8040S includes 16 ray tracing cores, which the MI455X does not list. The 8040S supports modern graphics APIs, while the MI455X lists N/A for all of them. The 8040S has a much lower TDP of 55 W versus 2300 W, and it fits as an IGP rather than an EAM Module. For any task that requires display output, rasterization, ray tracing, or standard graphics API compatibility, the 8040S has the only functional path.

The 8040S also has a real benchmark footprint. Its average score of 2440 and its placement at the 17th percentile versus all GPUs provide a concrete reference point. The MI455X has no such data. The 8040S is positioned within 1.1 percent of its nearest rivals, meaning it performs in line with other entry-level parts. The MI455X sits at the 50th percentile without any benchmark data, which the database records but does not explain further. In practical terms, the 8040S is a usable, measurable graphics solution, while the MI455X is a compute device that the database has not subjected to standard graphics benchmarks.

FAQ

Q: What is the FP32 performance difference between the two GPUs?

A: The MI455X delivers 157.3 TFLOPS in FP32, while the 8040S delivers 5.734 TFLOPS. The MI455X is approximately 27 times higher in raw floating-point throughput.

Q: Does the MI455X support DirectX or Vulkan?

A: The database lists DirectX, OpenGL, and Vulkan as N/A for the MI455X. The 8040S supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: How much memory does each GPU have?

A: The MI455X has 432 GB of HBM4 memory on a 24576-bit bus with 23.3 TB/s bandwidth. The 8040S uses system shared memory, with size, type, bus width, and bandwidth all listed as system dependent.

Q: What are the TDP values for these GPUs?

A: The MI455X has a TDP of 2300 W with a suggested PSU of 2700 W. The 8040S has a TDP of 55 W and no suggested PSU listed.

Q: Which GPU has ray tracing cores?

A: The 8040S has 16 ray tracing cores. The MI455X does not list any ray tracing cores in the database.

Q: What is the average benchmark score for the 8040S?

A: The 8040S has an average benchmark score of 2440, with a percentile of 17 versus all GPUs. Its best individual score is 10578 in passmark_g3d.

Specification Differences

The following fields differ between the two parts according to the database:

• Chip: MI450 256CU versus Strix Halo
• Architecture: CDNA 5.0 versus RDNA 3.5
• Generation: Instinct (MIx) versus Navi Mobile (RX 8000M)
• Process node: 2 nm versus 4 nm
• Transistors: 320,000 million versus unknown
• Die size: 2990 mm² versus 308 mm²
• Transistor density: 107.0M / mm² versus null
• Base clock: 1000 MHz versus 1295 MHz
• Boost clock: 2400 MHz versus 2800 MHz
• Memory clock: 1900 MHz 7.6 Gbps effective versus system shared
• Memory size: 432 GB versus system shared
• Memory type: HBM4 versus system shared
• Memory bus width: 24576 bit versus system shared
• Memory bandwidth: 23.3 TB/s versus system dependent
• Shading units: 32768 versus 1024
• TMUs: 1024 versus 64
• ROPs: 0 versus 32
• Ray tracing cores: null versus 16
• Pixel rate: 0 MPixel/s versus 89.60 GPixel/s
• Texture rate: 2457.6 GTexel/s versus 179.2 GTexel/s
• FP32: 157.3 TFLOPS versus 5.734 TFLOPS
• FP16: 157.3 TFLOPS (1:1) versus 5.734 TFLOPS (1:1)
• TDP: 2300 W versus 55 W
• Slot width: EAM Module versus IGP
• Suggested PSU: 2700 W versus null
• Bus interface: PCIe 6.0 x16 versus PCIe 5.0 x16
• Display outputs: No outputs versus portable device dependent
• DirectX: N/A versus 12 Ultimate (12_2)
• OpenGL: N/A versus 4.6
• Vulkan: N/A versus 1.4
• Release date: 2026-07-22 versus 2025-01-05
• Production status: null versus Active
• Predecessor: Radeon Instinct versus Polaris Mobile

Fields that match include the manufacturer (AMD), the foundry (TSMC), the power connector type (None), and the lack of a launch MSRP in the database.

The Verdict

The data supports a clear split. The AMD Instinct MI455X is a compute accelerator for workloads that demand extreme floating-point throughput, massive memory capacity, and very high bandwidth. Its 157.3 TFLOPS FP32 performance, 432 GB of HBM4 memory, and 23.3 TB/s bandwidth place it in a category that the 8040S cannot approach. Its 2300 W TDP and EAM Module form factor indicate a server or datacenter installation, not a consumer desktop. The lack of display outputs and graphics API support reinforces this: the MI455X is not built for rendering frames or running consumer applications.

The AMD Radeon 8040S is an integrated GPU for mobile systems. It delivers 5.734 TFLOPS FP32, has 32 ROPs, 16 ray tracing cores, and full support for DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4. Its 55 W TDP makes it suitable for laptops or portable devices, and its display outputs are described as portable device dependent. Its benchmark scores, which place it at the 17th percentile with an average of 2440, show that it performs in line with other low-end GPUs from the same era, within 1.1 percent of its nearest rivals.

For a user or system builder seeking a GPU for standard graphics workloads, gaming, or mobile computing, the 8040S is the only viable option in this comparison. It has the APIs, the ROPs, the ray tracing cores, and the benchmark data to support such use. For anyone assembling a high-performance compute node for AI training, scientific simulation, or similar tasks, the MI455X offers a scale of resources that the 8040S cannot match. The database does not include benchmarks for the MI455X, so its real-world performance cannot be quantified here, but its specifications alone position it as a much more powerful compute device. The choice depends entirely on the workload: consumer graphics versus datacenter compute.