AMD Radeon 840M vs AMD Radeon RX 6450M Comparison

Head-to-Head Benchmarks

The recorded database contains no benchmark scores for either the AMD Radeon 840M or the AMD Radeon RX 6450M. Both entries show an average benchmark score of zero, and the head-to-head benchmark list is empty. Consequently, there are no measured wins for either part in any workload category. The absence of data means that any direct performance comparison must be inferred from the architectural and specification differences rather than from empirical results.

Both GPUs occupy the 50th percentile among all GPUs in the database, which places them at the midpoint of the recorded performance distribution. However, this percentile ranking is derived from the full set of GPUs in the database, and with no individual benchmark scores recorded for either part, the percentile value does not reflect a measured performance advantage for one over the other. The data indicates that neither product has been subjected to the database's standard benchmark suite, or the results have not been populated for either entry.

Without recorded scores, the analysis shifts to the theoretical peak rates listed in the specification fields. The Radeon RX 6450M delivers a pixel rate of 78.72 GPixel/s, which is more than three times the 23.20 GPixel/s of the Radeon 840M. The texture rate shows a similar disparity: 118.1 GTexel/s versus 46.40 GTexel/s. The floating-point throughput difference is even more pronounced, with the RX 6450M reaching 3.779 TFLOPS in FP32, while the 840M achieves 1,484.8 GFLOPS, which is roughly 1.48 TFLOPS. The RX 6450M therefore offers approximately 2.5 times the FP32 compute of the 840M based on the peak specifications.

The FP16 comparison introduces an additional distinction. The RX 6450M lists FP16 at 7.557 TFLOPS with a 2:1 ratio relative to FP32, meaning it can double its throughput when operating on half-precision data. The 840M lists FP16 at 1,484.8 GFLOPS with a 1:1 ratio, indicating no such doubling capability. In FP16 workloads, the RX 6450M would theoretically deliver over five times the throughput of the 840M. These are the only quantitative performance indicators available in the database.

Architecture Differences

The two GPUs belong to different architectural generations. The Radeon 840M uses RDNA 3.5 and is part of the Navi III IGP (Strix Point Mobile) generation, built on a 4 nm process at TSMC. The Radeon RX 6450M uses RDNA 2.0, belongs to the Navi Mobile (RX 6000M) generation, and is fabricated on a 6 nm process, also at TSMC. The process node difference gives the 840M a manufacturing advantage in terms of density and power efficiency potential, though the RX 6450M's larger transistor budget compensates in raw throughput.

The RX 6450M contains 5,400 million transistors on a die size of 107 mm², yielding a transistor density of 50.5 million transistors per square millimeter. The 840M's transistor count and die size are listed as unknown in the database, so no direct density comparison is possible. The RX 6450M's discrete-class design with dedicated memory stands in contrast to the 840M's integrated graphics approach, which relies on system memory.

The shading architecture differs substantially. The RX 6450M has 768 shading units, 48 texture mapping units, and 32 render output units. The 840M has 256 shading units, 16 texture mapping units, and 8 render output units. The ray tracing hardware also differs: the RX 6450M includes 12 ray tracing cores, while the 840M has 4. Neither part lists tensor cores, so there is no AI acceleration hardware in either chip.

Memory architecture is a fundamental differentiator. The 840M uses system shared memory, with its bandwidth described as system dependent. The RX 6450M has 4 GB of dedicated GDDR6 memory on a 64-bit bus, delivering 128.0 GB/s of bandwidth. The memory clock for the RX 6450M is listed as 2000 MHz with 16 Gbps effective speed. The 840M's memory operates at system shared speed, which varies by platform. The RX 6450M's dedicated memory provides predictable bandwidth, while the 840M's performance depends entirely on the host system's memory configuration.

Both parts support the same API feature set: DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The bus interface differs, with the 840M using PCIe 4.0 x8 and the RX 6450M using PCIe 4.0 x4. The RX 6450M's narrower bus is offset by its dedicated memory, which reduces reliance on the system interconnect.

Where Each One Wins

Based on the specification data, the Radeon RX 6450M holds the advantage in every measurable performance category. Its pixel rate of 78.72 GPixel/s versus 23.20 GPixel/s indicates a clear lead in fill-rate-bound scenarios, such as high-resolution rasterization with heavy overdraw. The texture rate of 118.1 GTexel/s versus 46.40 GTexel/s gives it a strong position in texture-heavy workloads, including modern game engines that rely on detailed material sampling. The FP32 throughput of 3.779 TFLOPS versus 1,484.8 GFLOPS means the RX 6450M is better suited to general-purpose compute tasks, shader-heavy effects, and physics simulations.

The FP16 capability of the RX 6450M at 7.557 TFLOPS, with its 2:1 ratio, makes it particularly effective in workloads that use half-precision arithmetic, such as certain image processing pipelines and machine learning inference tasks that do not require tensor cores. The 840M's FP16 throughput matches its FP32 rate at 1,484.8 GFLOPS, offering no advantage for half-precision work. In ray tracing, the RX 6450M's 12 ray tracing cores versus 4 on the 840M suggests a significant lead in ray-traced rendering, though no benchmark scores are available to confirm the practical impact.

The 840M does have advantages in specific areas. Its 4 nm process node indicates a more modern manufacturing technology, which typically translates to better power efficiency per transistor. Its 15 W TDP versus the RX 6450M's 50 W TDP means it consumes one-third of the power envelope. The 840M's PCIe 4.0 x8 interface provides twice the lane width of the RX 6450M's PCIe 4.0 x4 connection, which matters when the 840M must pull data from system memory. In systems with high-bandwidth shared memory, the 840M could potentially reduce the gap in memory-bound scenarios, though the RX 6450M's dedicated 128.0 GB/s bandwidth remains a substantial advantage.

For integrated graphics duty in thin-and-light portable devices, the 840M's 15 W power draw and system-shared memory model make it suitable for devices without dedicated VRAM. The RX 6450M, despite being labeled as IGP in slot width, carries a 50 W TDP and its own 4 GB GDDR6, positioning it for more demanding mobile workloads where power consumption is less constrained.

Specification Differences

The two parts differ across nearly every core specification field. The process node is 4 nm for the 840M versus 6 nm for the RX 6450M. The RX 6450M lists 5,400 million transistors on a 107 mm² die, while the 840M's transistor count and die size are unknown. The RX 6450M has a transistor density of 50.5 million per square millimeter; no equivalent figure exists for the 840M.

Clock speeds show a significant divergence. The 840M has a base clock of 400 MHz and a boost clock of 2900 MHz. The RX 6450M has a base clock of 2000 MHz, a game clock of 2220 MHz, and a boost clock of 2460 MHz. The RX 6450M's base clock is five times higher than the 840M's base clock, though the 840M's boost clock exceeds the RX 6450M's boost clock by 440 MHz. The RX 6450M also lists a dedicated game clock, which the 840M does not have.

Memory specifications are entirely different. The 840M uses system shared memory with system shared type and bus width, and its bandwidth is system dependent. The RX 6450M uses 4 GB of GDDR6 on a 64-bit bus with 128.0 GB/s bandwidth. The RX 6450M's memory clock is 2000 MHz with 16 Gbps effective speed; the 840M has no independent memory clock.

The compute unit counts differ: 256 shading units, 16 TMUs, 8 ROPs, and 4 RT cores for the 840M, versus 768 shading units, 48 TMUs, 32 ROPs, and 12 RT cores for the RX 6450M. The pixel rate is 23.20 GPixel/s versus 78.72 GPixel/s. The texture rate is 46.40 GTexel/s versus 118.1 GTexel/s. FP32 throughput is 1,484.8 GFLOPS versus 3.779 TFLOPS. FP16 throughput is 1,484.8 GFLOPS (1:1) versus 7.557 TFLOPS (2:1).

Power consumption differs by a factor of more than three: 15 W for the 840M versus 50 W for the RX 6450M. The bus interface is PCIe 4.0 x8 for the 840M and PCIe 4.0 x4 for the RX 6450M. Both use the same display outputs (portable device dependent), power connectors (none), and slot width (IGP). The release dates are separated by over two years: the RX 6450M released on 2023-01-03, and the 840M released on 2025-02-28. The RX 6450M's predecessor is Polaris Mobile, while the 840M's predecessor is Navi II IGP. Neither part has a successor listed, and neither has a launch MSRP recorded.

FAQ

Q: Which GPU has higher FP32 compute throughput?

A: The AMD Radeon RX 6450M has higher FP32 throughput at 3.779 TFLOPS, compared to 1,484.8 GFLOPS for the AMD Radeon 840M. This gives the RX 6450M approximately 2.5 times the single-precision compute performance.

Q: How do the memory systems differ between the two GPUs?

A: The Radeon 840M uses system shared memory with bandwidth that is system dependent. The Radeon RX 6450M has 4 GB of dedicated GDDR6 memory on a 64-bit bus, delivering 128.0 GB/s of bandwidth. The RX 6450M's memory is clocked at 2000 MHz with 16 Gbps effective speed.

Q: What is the power consumption difference?

A: The Radeon 840M has a TDP of 15 W, while the Radeon RX 6450M has a TDP of 50 W. The 840M consumes one-third of the power of the RX 6450M, making it more suitable for power-constrained portable devices.

Q: Which GPU has more ray tracing cores?

A: The Radeon RX 6450M has 12 ray tracing cores, while the Radeon 840M has 4 ray tracing cores. The RX 6450M provides three times the ray tracing hardware of the 840M.

Q: What are the architectural generations of each GPU?

A: The Radeon 840M uses RDNA 3.5 architecture, part of the Navi III IGP (Strix Point Mobile) generation, built on a 4 nm process. The Radeon RX 6450M uses RDNA 2.0 architecture, part of the Navi Mobile (RX 6000M) generation, built on a 6 nm process.

Q: Do both GPUs support the same APIs?

A: Yes, both the Radeon 840M and the Radeon RX 6450M support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. There is no difference in the API feature set between the two parts.