AMD Instinct MI455X vs AMD Radeon 780M Comparison

FAQ

Q: What is the AMD Instinct MI455X?

A: The AMD Instinct MI455X is a data center compute accelerator built on the CDNA 5.0 architecture, featuring the MI450 256CU chip. It uses a 2 nm process from TSMC, contains 320,000 million transistors on a 2990 mm² die, and is part of the Instinct (MIx) generation.

Q: What is the AMD Radeon 780M?

A: The AMD Radeon 780M is an integrated graphics processor (IGP) based on the RDNA 3.0 architecture, using the Phoenix chip on a 4 nm TSMC process. It contains 25,390 million transistors on a 178 mm² die and belongs to the Navi III IGP (Phoenix) generation.

Q: Which card has more shading units?

A: The Instinct MI455X has 32,768 shading units, while the Radeon 780M has 768. The Instinct MI455X also has 1,024 texture mapping units versus 48 on the Radeon 780M.

Q: What is the memory setup for each?

A: The Instinct MI455X uses 432 GB of HBM4 memory with a 24,576-bit bus and 23.3 TB/s bandwidth. The Radeon 780M uses system shared memory, with system dependent bandwidth and a system shared bus width.

Q: What are the benchmark scores for the Radeon 780M?

A: The Radeon 780M records an average benchmark score of 17,588. Its individual tests include 480 in 3DMark Steel Nomad DX12, 18,602 in Geekbench OpenCL, and 33,683 in Geekbench Vulkan.

Q: Does the Instinct MI455X have any benchmark scores?

A: No. The database shows no benchmark entries for the Instinct MI455X, and its average benchmark score is recorded as 0, with a percentile rank of 50 among all GPUs.

The Verdict

The AMD Instinct MI455X is a compute accelerator with no display outputs, no graphics APIs, and zero recorded benchmarks. Its design targets raw compute throughput: 157.3 TFLOPS FP32, 23.3 TB/s memory bandwidth, and a 2,300 W TDP. The Radeon 780M, by contrast, is an active integrated GPU with a 15 W TDP, full DirectX 12 Ultimate support, and a measurable benchmark record. For any workload involving graphics output, gaming, or standard API-based rendering, the Radeon 780M is the only functional choice. For massive parallel compute tasks that do not require display output, the Instinct MI455X delivers vastly higher raw specifications, though the database contains no empirical scores to verify its performance.

The Radeon 780M holds a 61st percentile rank among all GPUs, while the Instinct MI455X sits at the 50th percentile with no test data. The Radeon 780M's nearest rivals in the database include the AMD Radeon Pro 560 (0.2% ahead), the NVIDIA GeForce RTX 4060 (0.3% behind), and the AMD Radeon HD 7790 (0.4% behind). This places the 780M in a competitive mid-range position for an integrated part. The Instinct MI455X has no rivals listed, reflecting its distinct category.

Head-to-Head Benchmarks

The database records no direct head-to-head benchmarks between the Instinct MI455X and the Radeon 780M. The wins count stands at zero for both sides. This means the comparison must rely on the available specification data and the Radeon 780M's standalone benchmark results.

The Radeon 780M delivers a 3DMark Steel Nomad DX12 score of 480, a Geekbench OpenCL score of 18,602, and a Geekbench Vulkan score of 33,683. Its average benchmark score of 17,588 places it within 0.3% of the NVIDIA GeForce RTX 4060, which scores 17,639. It trails the AMD Radeon HD 7790 (17,666) by 0.4% and leads the AMD Radeon Pro 560 (17,551) by 0.2% and the AMD Radeon Pro 460 (17,509) by 0.5%. These narrow margins indicate the 780M performs at parity with discrete desktop GPUs from previous generations.

The Instinct MI455X has no recorded benchmark scores, so no direct performance comparison is possible from measured data. Its FP32 throughput of 157.3 TFLOPS is 17.7 times the Radeon 780M's 8.909 TFLOPS, but this is a specification comparison, not a benchmark result. The texture rate of 2,457.6 GTexel/s versus 139.2 GTexel/s similarly shows a massive theoretical gap in fill-rate capacity.

Specification Differences

The two processors differ fundamentally in nearly every measurable specification. The Instinct MI455X uses a 2 nm process node, while the Radeon 780M uses 4 nm. Transistor counts differ by an order of magnitude: 320,000 million versus 25,390 million. Die sizes are 2990 mm² versus 178 mm², making the Instinct MI455X roughly 17 times larger physically. Transistor density is lower on the Instinct part at 107.0 million per mm², compared to 142.6 million per mm² on the Radeon 780M.

Clock speeds show different strategies. The Instinct MI455X has a 1000 MHz base and 2400 MHz boost. The Radeon 780M has an 800 MHz base and 2900 MHz boost, giving the integrated part a higher peak clock. Memory clocks are 1900 MHz (7.6 Gbps effective) for the Instinct, while the Radeon uses system shared memory. Memory capacity is 432 GB of HBM4 versus system shared. Bus width is 24,576 bit versus system shared. Bandwidth is 23.3 TB/s versus system dependent.

Power draw differs dramatically: 2,300 W TDP for the Instinct MI455X versus 15 W for the Radeon 780M. The suggested PSU for the Instinct is 2,700 W, while the Radeon lists none. The slot type is an EAM Module for the Instinct and IGP for the Radeon. The bus interface is PCIe 6.0 x16 on the Instinct versus PCIe 4.0 x8 on the Radeon. Display outputs are absent on the Instinct and motherboard dependent on the Radeon. The Instinct has no graphics APIs, while the Radeon supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Architecture Differences

The Instinct MI455X is built on CDNA 5.0, AMD's compute-focused architecture. It features 32,768 shading units, 1,024 TMUs, and zero ROPs. Pixel rate is 0 MPixel/s, confirming it is not designed for rasterization. The FP32 and FP16 throughput are both 157.3 TFLOPS with a 1:1 ratio, indicating a compute-first design with no dedicated ray tracing or tensor cores listed. The memory subsystem uses HBM4 with a 432 GB capacity, and the chip integrates 320,000 million transistors.

The Radeon 780M uses RDNA 3.0, a graphics-oriented architecture. It has 768 shading units, 48 TMUs, and 32 ROPs. It includes 12 ray tracing cores, a feature entirely absent from the Instinct part. Pixel rate is 92.80 GPixel/s and texture rate is 139.2 GTexel/s. FP32 and FP16 are both 8.909 TFLOPS with a 1:1 ratio. The Radeon supports DirectX 12 Ultimate with feature level 12_2, OpenGL 4.6, and Vulkan 1.4, making it fully compatible with modern graphics APIs. The Instinct MI455X lists N/A for all graphics APIs.

The process nodes reflect their different purposes: the 2 nm node on a 2990 mm² die for the Instinct versus the 4 nm node on a 178 mm² die for the Radeon. The Instinct's lower transistor density (107.0M per mm²) compared to the Radeon's 142.6M per mm² suggests the Instinct allocates more die area to memory controllers and compute arrays rather than dense logic. The Radeon 780M's higher density reflects its integrated nature, sharing the Phoenix die with CPU cores.

Where Each One Wins

The Radeon 780M wins in any scenario requiring graphics output. It has display outputs (motherboard dependent), supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, and has 32 ROPs for rasterization. Its 12 ray tracing cores enable hardware-accelerated ray tracing, a feature the Instinct MI455X does not list. The 780M's 15 W TDP makes it suitable for power-constrained environments, and its benchmark scores confirm it performs in the same range as discrete GPUs like the NVIDIA GeForce RTX 4060 and AMD Radeon Pro 560.

The Instinct MI455X wins in raw compute specifications. Its 157.3 TFLOPS FP32 is 17.7 times the Radeon 780M's 8.909 TFLOPS. Its 23.3 TB/s memory bandwidth is not comparable to the Radeon's system dependent bandwidth. The 432 GB HBM4 memory capacity supports massive datasets, and the 2,457.6 GTexel/s texture rate indicates extreme texture processing capability. The PCIe 6.0 x16 interface provides high-bandwidth host connectivity.

For gaming, rendering, or any visual workload, the Radeon 780M is the only viable option, as the Instinct has no display outputs and no graphics API support. For machine learning training, scientific simulation, or data center compute tasks that operate without display output, the Instinct MI455X offers specifications that dwarf the integrated part, though the absence of recorded benchmarks means its real-world performance remains unverified in the database. The Radeon 780M's active production status and available benchmark data make it the better-documented product, while the Instinct MI455X, with a 2026 release date and no production status, remains a specification-only entry.