AMD Instinct MI455X vs AMD Radeon RX 7700S Comparison

The Verdict

The AMD Instinct MI455X and AMD Radeon RX 7700S serve entirely different purposes, and the data confirms they should never be cross-shopped. The MI455X is a compute accelerator with 432 GB of HBM4 memory, 32,768 shading units, and 157.3 TFLOPS of FP32 throughput, built on a 2 nm process with a 2300 W thermal envelope. The RX 7700S is a 100 W mobile graphics processor with 8 GB of GDDR6 memory, 2,048 shading units, and 20.48 TFLOPS of FP32, designed for portable devices. The MI455X has no display outputs, no graphics API support, and a zero pixel rate; the RX 7700S delivers DirectX 12 Ultimate, OpenGL 4.6, Vulkan 1.4, and a 160.0 GPixel/s pixel rate. Users who need rendering, gaming, or any visual output should choose the RX 7700S. Users who need massive memory capacity and raw compute throughput for non-visual workloads should choose the MI455X. The benchmark database records no head-to-head comparisons between them, and the MI455X has no recorded benchmark scores, while the RX 7700S sits at the 78th percentile among all GPUs with an average benchmark score of 33,849. The MI455X sits at the 50th percentile with a score of zero, which reflects the absence of test data rather than actual performance.

Architecture Differences

The two processors share a manufacturer but diverge completely in architecture. The MI455X uses CDNA 5.0, the latest compute-oriented design from AMD, built on a 2 nm process at TSMC. The RX 7700S uses RDNA 3.0, the graphics-oriented architecture, also fabricated by TSMC but on a 6 nm process. The MI455X carries the chip designation "MI450 256CU" and belongs to the Instinct (MIx) generation, while the RX 7700S uses the Navi 33 chip with the codename "Hotpink Bonefish" and belongs to the Navi Mobile (RX 7000M) generation. The MI455X is a module with an EAM slot width, while the RX 7700S is an IGP (integrated graphics processor) for portable systems.

Transistor counts differ by an order of magnitude. The MI455X packs 320,000 million transistors on a 2990 mm² die, yielding a transistor density of 107.0M per mm². The RX 7700S contains 13,300 million transistors on a 204 mm² die, with a density of 65.2M per mm². The MI455X die is roughly 14.7 times larger in area and holds about 24 times more transistors.

Memory architecture is fundamentally different. The MI455X uses 432 GB of HBM4 across a 24,576-bit bus, delivering 23.3 TB/s of bandwidth. The RX 7700S uses 8 GB of GDDR6 on a 128-bit bus, delivering 288.0 GB/s. The MI455X memory bandwidth is approximately 80.9 times higher, and capacity is 54 times larger. Clock speeds also differ: the MI455X has a base clock of 1000 MHz and a boost of 2400 MHz, while the RX 7700S has a base of 1500 MHz, a game clock of 2200 MHz, and a boost of 2500 MHz.

Compute resources show a similar split. The MI455X has 32,768 shading units and 1,024 texture mapping units, with zero ROPs, zero ray tracing cores, and zero tensor cores. The RX 7700S has 2,048 shading units, 128 TMUs, 64 ROPs, and 32 ray tracing cores. The MI455X texture rate is 2,457.6 GTexel/s versus 320.0 GTexel/s for the RX 7700S, a 7.7 times difference. FP16 throughput also contrasts sharply: the MI455X delivers 157.3 TFLOPS with a 1:1 ratio to FP32, while the RX 7700S delivers 40.96 TFLOPS at a 2:1 ratio, meaning its FP16 rate is double its FP32 rate. The MI455X has no pixel rate (0 MPixel/s) because it lacks ROPs entirely. The RX 7700S outputs 160.0 GPixel/s.

Interface and power handling differ as well. The MI455X uses PCIe 6.0 x16, requires a 2700 W suggested PSU, and draws 2300 W TDP. The RX 7700S uses PCIe 4.0 x16, has no suggested PSU figure, and draws 100 W TDP. Neither uses external power connectors. The MI455X has no display outputs; the RX 7700S outputs are portable device dependent.

Head-to-Head Benchmarks

The database contains no head-to-head benchmark entries between the MI455X and RX 7700S. The win count is zero for both. However, the RX 7700S has three recorded benchmark scores. In 3DMark Steel Nomad DX12, it scores 2,185. In Geekbench OpenCL, it scores 62,983. In Geekbench Vulkan, it scores 36,380. Its average benchmark score is 33,849, placing it at the 78th percentile among all GPUs.

The nearest rivals for the RX 7700S provide context. The AMD Radeon HD 7950 has an average score of 33,951, which is 0.3% higher than the RX 7700S. The AMD Radeon RX 480 scores 33,997, 0.4% higher. The NVIDIA GeForce GTX 1060 5 GB scores 33,694, which is 0.5% lower than the RX 7700S. The NVIDIA RTX A5000 scores 33,622, 0.7% lower. This places the RX 7700S in a tight cluster where the spread between the fastest and slowest rival is only 1.1%. The RX 7700S effectively trades positions with older and newer cards within a narrow performance band, according to the recorded data.

The MI455X has no benchmark scores, no nearest rivals, and a percentile of 50 with an average score of zero. This means the database has no measured performance data for the MI455X. Its capabilities must be assessed from architectural specifications alone. The FP32 throughput of 157.3 TFLOPS is 7.7 times higher than the RX 7700S's 20.48 TFLOPS. Memory bandwidth of 23.3 TB/s dwarfs the RX 7700S's 288.0 GB/s. Texture rate of 2,457.6 GTexel/s exceeds the RX 7700S's 320.0 GTexel/s by the same 7.7 factor. These figures indicate a compute-oriented part with massive throughput, but no measured benchmark confirms real-world behavior.

The absence of head-to-head data means any direct performance comparison relies entirely on specification differences. The recorded information shows the MI455X wins on raw compute metrics, memory capacity, memory bandwidth, texture rate, and FP16 throughput. The RX 7700S wins on pixel rate, ray tracing cores, graphics API support, and having any benchmark scores at all. The MI455X has zero ROPs and zero pixel rate, making it incapable of rasterization. The RX 7700S has 64 ROPs and a 160.0 GPixel/s rate, making it a functional graphics processor.

FAQ

Q: Which processor has more memory?

A: The AMD Instinct MI455X has 432 GB of HBM4 memory. The AMD Radeon RX 7700S has 8 GB of GDDR6 memory. The MI455X memory capacity is 54 times larger.

Q: Which processor supports graphics APIs?

A: The AMD Radeon RX 7700S supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The AMD Instinct MI455X lists N/A for DirectX, OpenGL, and Vulkan, meaning no graphics API support is recorded.

Q: What is the thermal design power of each processor?

A: The AMD Instinct MI455X has a TDP of 2300 W and a suggested PSU of 2700 W. The AMD Radeon RX 7700S has a TDP of 100 W and no suggested PSU figure.

Q: Which processor has ray tracing cores?

A: The AMD Radeon RX 7700S has 32 ray tracing cores. The AMD Instinct MI455X has no ray tracing cores listed.

Q: What is the FP32 throughput difference?

A: The AMD Instinct MI455X delivers 157.3 TFLOPS FP32. The AMD Radeon RX 7700S delivers 20.48 TFLOPS FP32. The MI455X is 7.7 times higher.

Q: Does the MI455X have any benchmark scores?

A: No. The MI455X has an empty benchmark list, an average benchmark score of zero, and no nearest rivals. The RX 7700S has three benchmark scores: 2,185 in 3DMark Steel Nomad DX12, 62,983 in Geekbench OpenCL, and 36,380 in Geekbench Vulkan.

Where Each One Wins

The AMD Instinct MI455X wins decisively in compute throughput and memory capacity. Its 157.3 TFLOPS FP32 and 157.3 TFLOPS FP16 (1:1) represent the highest recorded arithmetic rates in this comparison. Its 432 GB HBM4 memory with 23.3 TB/s bandwidth provides a memory subsystem that the RX 7700S cannot approach. The MI455X also leads in texture rate at 2,457.6 GTexel/s, transistor count at 320,000 million, die size at 2990 mm², and transistor density at 107.0M per mm². It uses a newer 2 nm process node versus 6 nm, and a newer PCIe 6.0 x16 interface versus PCIe 4.0 x16. The MI455X is built for workloads that require enormous memory capacity and sustained compute, such as large-scale data processing, where visual output is irrelevant.

The AMD Radeon RX 7700S wins in all graphics-specific metrics. It has 64 ROPs and a 160.0 GPixel/s pixel rate, while the MI455X has zero ROPs and a 0 MPixel/s pixel rate. It has 32 ray tracing cores, which the MI455X lacks entirely. It supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, while the MI455X supports none. It has display outputs, albeit portable device dependent, while the MI455X has no outputs. It has a game clock of 2200 MHz and a higher boost clock of 2500 MHz versus 2400 MHz for the MI455X. Its FP16 throughput at 40.96 TFLOPS uses a 2:1 ratio, meaning it processes half-precision at twice the FP32 rate, a feature useful for certain graphics workloads. The RX 7700S also has a much lower TDP at 100 W versus 2300 W, and it has recorded benchmark scores with a 78th percentile ranking. The RX 7700S is the only one of the two that can render frames, output video, or run graphics APIs.

The RX 7700S also wins on portability. It is an IGP with a 100 W TDP, designed for portable devices. The MI455X is an EAM module with a 2300 W TDP and a 2700 W suggested PSU, which requires substantial power delivery infrastructure. The RX 7700S has a production status of Active, while the MI455X has no production status recorded. The RX 7700S release date of 2023-01-03 is earlier than the MI455X release date of 2026-07-22, but both are recorded in the database.

Specification Differences

The following fields differ between the two processors:

Architecture: CDNA 5.0 for the MI455X versus RDNA 3.0 for the RX 7700S.

Chip: MI450 256CU for the MI455X versus Navi 33 for the RX 7700S.

Codename: None for the MI455X versus Hotpink Bonefish for the RX 7700S.

Generation: Instinct (MIx) for the MI455X versus Navi Mobile (RX 7000M) for the RX 7700S.

Process node: 2 nm for the MI455X versus 6 nm for the RX 7700S.

Transistors: 320,000 million for the MI455X versus 13,300 million for the RX 7700S.

Die size: 2990 mm² for the MI455X versus 204 mm² for the RX 7700S.

Transistor density: 107.0M / mm² for the MI455X versus 65.2M / mm² for the RX 7700S.

Base clock: 1000 MHz for the MI455X versus 1500 MHz for the RX 7700S.

Boost clock: 2400 MHz for the MI455X versus 2500 MHz for the RX 7700S.

Game clock: None for the MI455X versus 2200 MHz for the RX 7700S.

Memory clock: 1900 MHz (7.6 Gbps effective) for the MI455X versus 2250 MHz (18 Gbps effective) for the RX 7700S.

Memory size: 432 GB for the MI455X versus 8 GB for the RX 7700S.

Memory type: HBM4 for the MI455X versus GDDR6 for the RX 7700S.

Memory bus width: 24576 bit for the MI455X versus 128 bit for the RX 7700S.

Memory bandwidth: 23.3 TB/s for the MI455X versus 288.0 GB/s for the RX 7700S.

Shading units: 32768 for the MI455X versus 2048 for the RX 7700S.

TMUs: 1024 for the MI455X versus 128 for the RX 7700S.

ROPs: 0 for the MI455X versus 64 for the RX 7700S.

Ray tracing cores: None for the MI455X versus 32 for the RX 7700S.

Pixel rate: 0 MPixel/s for the MI455X versus 160.0 GPixel/s for the RX 7700S.

Texture rate: 2,457.6 GTexel/s for the MI455X versus 320.0 GTexel/s for the RX 7700S.

FP32: 157.3 TFLOPS for the MI455X versus 20.48 TFLOPS for the RX 7700S.

FP16: 157.3 TFLOPS (1:1) for the MI455X versus 40.96 TFLOPS (2:1) for the RX 7700S.

TDP: 2300 W for the MI455X versus 100 W for the RX 7700S.

Slot width: EAM Module for the MI455X versus IGP for the RX 7700S.

Suggested PSU: 2700 W for the MI455X versus none for the RX 7700S.

Bus interface: PCIe 6.0 x16 for the MI455X versus PCIe 4.0 x16 for the RX 7700S.

Display outputs: No outputs for the MI455X versus Portable Device Dependent for the RX 7700S.

DirectX: N/A for the MI455X versus 12 Ultimate (12_2) for the RX 7700S.

OpenGL: N/A for the MI455X versus 4.6 for the RX 7700S.

Vulkan: N/A for the MI455X versus 1.4 for the RX 7700S.

Production status: None for the MI455X versus Active for the RX 7700S.

Release date: 2026-07-22 for the MI455X versus 2023-01-03 for the RX 7700S.

Predecessor: Radeon Instinct for the MI455X versus Polaris Mobile for the RX 7700S.

Percentile: 50 for the MI455X versus 78 for the RX 7700S.

Average benchmark score: 0 for the MI455X versus 33,849 for the RX 7700S.

The two share the same manufacturer, foundry (TSMC), power connector configuration (none), and lack of launch MSRP data. Both have no listed dimensions. Both have no tensor cores. Both have no successor listed. The MI455X has no series designation, while the RX 7700S belongs to the Radeon RX 7000 series.