AMD Radeon 840M vs AMD Radeon RX 7900 GRE Comparison

The Verdict

The AMD Radeon 840M and AMD Radeon RX 7900 GRE occupy completely different segments of the graphics market, with the recorded data showing no overlap in performance. The RX 7900 GRE delivers 45.98 TFLOPS of FP32 compute, while the 840M delivers 1,484.8 GFLOPS, a gap of roughly 30 times. The RX 7900 GRE holds a 77th percentile ranking among all GPUs in the database, whereas the 840M sits at the 50th percentile with no recorded benchmark scores. For any application requiring discrete graphics performance, the RX 7900 GRE is the clear choice. The 840M, as an integrated GPU with a 15 W TDP, serves systems where power consumption and space are the primary constraints. The RX 7900 GRE also carries a launch MSRP of 549 USD, which reflects its position as a dedicated add-in card.

Architecture Differences

The two GPUs come from different RDNA generations and process nodes. The RX 7900 GRE uses the RDNA 3.0 architecture with the Navi 31 chip, while the 840M uses RDNA 3.5 with the Krackan Point chip. The RX 7900 GRE is built on a 5 nm process at TSMC, whereas the 840M uses a 4 nm process at the same foundry. The RX 7900 GRE packs 57,700 million transistors on a 529 mm² die, giving a transistor density of 109.1 million per mm². The 840M's transistor count and die size are listed as unknown in the database.

The RX 7900 GRE belongs to the Radeon RX 7000 series with the codename Plum Bonito, while the 840M is part of the Navi III IGP generation for Strix Point Mobile. The 840M's predecessor is listed as Navi II IGP, and the RX 7900 GRE's predecessor is Navi II with a successor of Navi IV. The RX 7900 GRE was released on 2023-07-26, while the 840M came later on 2025-02-28.

Feature sets differ substantially as well. The RX 7900 GRE includes 80 ray tracing cores, 5,120 shading units, 320 texture mapping units, and 160 render output units. The 840M has 4 ray tracing cores, 256 shading units, 16 TMUs, and 8 ROPs. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, so API coverage is identical. The RX 7900 GRE uses dual-slot cooling with 2x 8-pin power connectors and a suggested PSU of 600 W, while the 840M is an IGP with no power connectors and no suggested PSU listed.

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark comparisons between the two GPUs, and the 840M has no recorded benchmark scores at all. The RX 7900 GRE, however, has ten recorded benchmark entries across multiple test suites. Its average benchmark score is 32,456, with a percentile rank of 77 among all GPUs. The nearest rivals to the RX 7900 GRE in the database are the AMD FirePro S10000 with an average score of 32,388 (0.2% behind), the AMD FirePro S9300 X2 with 32,540 (0.3% ahead), the AMD Radeon RX 590 GME with 32,601 (0.4% ahead), and the AMD Radeon Pro 570X with 32,176 (0.9% behind).

Looking at individual benchmark results for the RX 7900 GRE, the 3DMark Steel Nomad DX12 test returns a score of 4,814. Geekbench OpenCL yields 175,758, and Geekbench Vulkan returns 99,850. Passmark tests show a G3D score of 27,089, a GPU compute score of 15,016, a G2D score of 1,180, DirectX 9 at 310, DirectX 11 at 300, DirectX 10 at 139, and DirectX 12 at 107. These numbers indicate strong compute performance in OpenCL and solid Vulkan results, with the DX9 and DX12 Passmark scores being relatively low compared to the G3D aggregate.

The 840M's lack of benchmark data means no direct performance comparison can be made from the database. Its theoretical specifications, however, point to a much lower ceiling. The pixel rate for the 840M is 23.20 GPixel/s versus 359.2 GPixel/s for the RX 7900 GRE. Texture rate is 46.40 GTexel/s versus 718.4 GTexel/s. These figures show the RX 7900 GRE exceeding the 840M by roughly 15 times in both rasterization throughput metrics.

FAQ

Q: What is the performance difference between the two GPUs based on recorded data?

A: The RX 7900 GRE has an average benchmark score of 32,456 and a 77th percentile ranking, while the 840M has no recorded benchmark scores and sits at the 50th percentile. The RX 7900 GRE's FP32 compute of 45.98 TFLOPS massively exceeds the 840M's 1,484.8 GFLOPS.

Q: Which GPU has more memory and bandwidth?

A: The RX 7900 GRE has 16 GB of GDDR6 memory on a 256-bit bus with 576.0 GB/s bandwidth. The 840M uses system-shared memory with a system-dependent bandwidth figure.

Q: Do both GPUs support the same graphics APIs?

A: Yes, both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4.

Q: What are the power requirements for each?

A: The RX 7900 GRE has a TDP of 260 W, requires 2x 8-pin power connectors, and needs a 600 W suggested PSU. The 840M has a 15 W TDP, no power connectors, and no suggested PSU.

Q: How does the RX 7900 GRE compare to its nearest rivals?

A: The RX 7900 GRE scores within 0.9% of its closest competitors in the database. It trails the AMD Radeon RX 590 GME by 0.4% and the AMD FirePro S9300 X2 by 0.3%, while leading the AMD FirePro S10000 by 0.2% and the AMD Radeon Pro 570X by 0.9%.

Q: What is the physical size difference?

A: The RX 7900 GRE is a dual-slot card measuring 276 mm in length, 110 mm in height, and 51 mm in width. The 840M is an integrated GPU with no dimensions listed.

Where Each One Wins

The RX 7900 GRE wins decisively in every measurable performance category. Its 5,120 shading units, 320 TMUs, and 160 ROPs provide a massive parallel processing capability that the 840M cannot approach. The RX 7900 GRE's 16 GB of GDDR6 memory with 576.0 GB/s bandwidth supports high-resolution textures and large datasets, while the 840M relies on system-shared memory with unspecified bandwidth. The RX 7900 GRE's 80 ray tracing cores enable hardware-accelerated ray tracing, and its 45.98 TFLOPS FP32 throughput handles compute-heavy workloads with ease.

The 840M wins in power efficiency and physical footprint. Its 15 W TDP is dramatically lower than the RX 7900 GRE's 260 W, making it suitable for portable systems where battery life and thermal limits matter. As an IGP with no power connectors and no dimensions, it integrates directly into a mobile chipset without requiring additional cooling or power delivery hardware. The 840M's 4 nm process node is more advanced than the RX 7900 GRE's 5 nm node, which contributes to its lower power draw.

For gaming and content creation, the RX 7900 GRE is the only viable option based on the recorded performance gap. For lightweight tasks such as basic display output, video playback, and low-intensity graphical workloads in a thin-and-light laptop, the 840M provides adequate functionality without the power overhead of a discrete GPU.

Specification Differences

| Specification | AMD Radeon 840M | AMD Radeon RX 7900 GRE |

|---|---|---|

| Architecture | RDNA 3.5 | RDNA 3.0 |

| Chip | Krackan Point | Navi 31 |

| Process Node | 4 nm | 5 nm |

| Transistors | unknown | 57,700 million |

| Die Size | unknown | 529 mm² |

| Base Clock | 400 MHz | 1287 MHz |

| Boost Clock | 2900 MHz | 2245 MHz |

| Game Clock | not specified | 1880 MHz |

| Memory Size | System Shared | 16 GB |

| Memory Type | System Shared | GDDR6 |

| Memory Bus Width | System Shared | 256 bit |

| Memory Bandwidth | System Dependent | 576.0 GB/s |

| Shading Units | 256 | 5120 |

| TMUs | 16 | 320 |

| ROPs | 8 | 160 |

| Ray Tracing Cores | 4 | 80 |

| Pixel Rate | 23.20 GPixel/s | 359.2 GPixel/s |

| Texture Rate | 46.40 GTexel/s | 718.4 GTexel/s |

| FP32 Performance | 1,484.8 GFLOPS | 45.98 TFLOPS |

| FP16 Performance | 1,484.8 GFLOPS (1:1) | 91.96 TFLOPS (2:1) |

| TDP | 15 W | 260 W |

| Slot Width | IGP | Dual-slot |

| Power Connectors | None | 2x 8-pin |

| Suggested PSU | not specified | 600 W |

| Bus Interface | PCIe 4.0 x8 | PCIe 4.0 x16 |

| Display Outputs | Portable Device Dependent | 1x HDMI 2.1a, 2x DisplayPort 2.1, 1x USB Type-C |

| Release Date | 2025-02-28 | 2023-07-26 |

| Production Status | Active | Active |

| Launch MSRP | not specified | 549 USD |

The specification table shows that the two GPUs differ in nearly every measurable aspect. The RX 7900 GRE has 20 times the shading units, 20 times the TMUs, 20 times the ROPs, 20 times the ray tracing cores, and approximately 31 times the FP32 compute throughput. The 840M's boost clock of 2900 MHz is higher than the RX 7900 GRE's 2245 MHz boost, but this does not compensate for the vast difference in execution resources. The RX 7900 GRE's 16 GB GDDR6 memory with 576.0 GB/s bandwidth stands in contrast to the 840M's system-shared memory, which cannot match dedicated graphics memory performance.