AMD Radeon 820M vs AMD Radeon 840M Comparison

The Verdict

The database comparison for the AMD Radeon 820M and AMD Radeon 840M shows two integrated graphics processors built on the same RDNA 3.5 architecture, the same 4 nm TSMC process, and the same Navi III IGP (Strix Point Mobile) generation. Both parts are designed for portable devices, feature system-shared memory, and carry a 15 W TDP. The recorded data indicates that the Radeon 840M is the substantially more capable part of the pair, with a doubled execution resource configuration across every compute stage. The Radeon 820M, by contrast, is configured with half the shading units, texture mapping units, render output units, and ray tracing cores.

For a user selecting between these two integrated GPUs, the data points clearly toward the Radeon 840M for any workload that relies on parallel compute, pixel throughput, or texture filtering. The Radeon 840M doubles the shading units from 128 to 256, doubles the TMUs from 8 to 16, doubles the ROPs from 4 to 8, and doubles the ray tracing cores from 2 to 4. These are not marginal improvements; they represent a full doubling of the fundamental processing blocks. The Radeon 820M remains a functional entry-level IGP, but its specifications place it at a distinct performance disadvantage in every measurable category except power draw and release timing, which are identical.

The Radeon 820M is the appropriate choice only when the host system is constrained to the absolute minimum GPU resource allocation, or when the workload is so light that the doubling of resources in the 840M is unnecessary. For general use, media playback, and light 2D rendering, the 820M's 128 shading units and 4 ROPs are sufficient. For gaming, 3D rendering, or any GPU-accelerated compute task, the Radeon 840M's doubled configuration delivers a meaningfully higher ceiling. The data does not support any scenario where the 820M outperforms the 840M; it only supports scenarios where the 840M's advantages are not fully utilized.

Architecture Differences

Both the AMD Radeon 820M and AMD Radeon 840M are built on the RDNA 3.5 architecture, which represents a refinement of AMD's RDNA family for integrated graphics in mobile platforms. The process node is identical at 4 nm, fabricated by TSMC. The generation classification is the same for both: Navi III IGP (Strix Point Mobile). The chip names differ slightly, with the 820M listed as "Krackan Point 2" and the 840M listed as "Krackan Point," but the underlying architecture and process are shared.

The core compute configuration is where the architectures diverge in execution resource count. The Radeon 820M contains 128 shading units, 8 texture mapping units, 4 render output units, and 2 ray tracing cores. The Radeon 840M contains exactly double each of these: 256 shading units, 16 TMUs, 8 ROPs, and 4 ray tracing cores. This doubling is consistent across all four categories, indicating that the 840M uses a fully expanded compute unit configuration relative to the 820M, rather than a partial increase in only one or two blocks.

The clock behavior also differs. Both parts share a 400 MHz base clock, but the boost clock is higher on the 840M at 2900 MHz versus 2800 MHz on the 820M. This 100 MHz boost advantage compounds the resource doubling, giving the 840M both more execution units and a higher maximum frequency. The memory subsystem is identical in architecture: both use system-shared memory with a system-dependent bandwidth, which means the actual memory performance is dictated by the host platform's memory configuration rather than by the GPU itself.

Feature support is identical between the two. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The bus interface is the same PCIe 4.0 x8 for both. Display outputs are portable-device dependent for both, meaning the integrated nature of these GPUs ties their output capabilities to the host laptop or handheld. Neither part has tensor cores listed in the database, and both lack dedicated power connectors due to their IGP slot width.

The transistor count and die size are listed as unknown for both parts, so no comparison can be made on physical silicon dimensions. Both are classified as Active production status and share the same release date of 2025-02-28. The predecessor is listed as Navi II IGP for both, and neither has a successor recorded.

FAQ

Q: Which GPU has more shading units?

A: The AMD Radeon 840M has 256 shading units, exactly double the 128 shading units found in the AMD Radeon 820M.

Q: Do both GPUs support the same DirectX version?

A: Yes, both the Radeon 820M and Radeon 840M support DirectX 12 Ultimate (12_2), along with OpenGL 4.6 and Vulkan 1.4.

Q: What is the boost clock difference between the two?

A: The Radeon 840M boosts to 2900 MHz, while the Radeon 820M boosts to 2800 MHz. The base clock is 400 MHz for both.

Q: Are the memory configurations different?

A: No, both GPUs use system-shared memory with a system-dependent bandwidth. The memory size, type, and bus width are all listed as system-shared for both parts.

Q: How do the pixel rates compare?

A: The Radeon 840M has a pixel rate of 23.20 GPixel/s, which is double the 11.20 GPixel/s of the Radeon 820M.

Q: Is the power consumption different?

A: No, both the Radeon 820M and Radeon 840M are listed with a 15 W TDP and no power connectors, as both are integrated GPUs.

Specification Differences

The following fields differ between the AMD Radeon 820M and AMD Radeon 840M in the recorded database:

• Chip: Krackan Point 2 for the 820M, Krackan Point for the 840M
• Boost Clock: 2800 MHz for the 820M, 2900 MHz for the 840M
• Shading Units: 128 for the 820M, 256 for the 840M
• Texture Mapping Units: 8 for the 820M, 16 for the 840M
• Render Output Units: 4 for the 820M, 8 for the 840M
• Ray Tracing Cores: 2 for the 820M, 4 for the 840M
• Pixel Rate: 11.20 GPixel/s for the 820M, 23.20 GPixel/s for the 840M
• Texture Rate: 22.40 GTexel/s for the 820M, 46.40 GTexel/s for the 840M
• FP32 Throughput: 716.8 GFLOPS for the 820M, 1,484.8 GFLOPS for the 840M
• FP16 Throughput: 716.8 GFLOPS (1:1) for the 820M, 1,484.8 GFLOPS (1:1) for the 840M

All other recorded fields are identical: base clock of 400 MHz, 4 nm process node, TSMC foundry, system-shared memory configuration, 15 W TDP, PCIe 4.0 x8 bus interface, DirectX 12 Ultimate (12_2), OpenGL 4.6, Vulkan 1.4, IGP slot width, no power connectors, portable-device-dependent display outputs, Active production status, 2025-02-28 release date, and Navi II IGP predecessor.

Head-to-Head Benchmarks

The database does not contain recorded benchmark scores for either the AMD Radeon 820M or the AMD Radeon 840M. The average benchmark score is 0 for both, and the percentile versus all GPUs is listed as 50 for both, which reflects the absence of measured performance data rather than an actual performance parity. The head-to-head benchmark array is empty, and the win counts are 0 for each part. Consequently, the comparison below relies entirely on the specification-derived throughput metrics recorded in the database.

The largest advantage for the Radeon 840M appears in the FP32 floating-point throughput. The 840M delivers 1,484.8 GFLOPS, which is more than double the 820M's 716.8 GFLOPS. The exact ratio is 2.071, meaning the 840M achieves 107.1% higher FP32 throughput. This advantage stems from the doubling of shading units combined with the higher boost clock. The FP16 throughput mirrors this exactly, with the 840M at 1,484.8 GFLOPS (1:1) versus the 820M at 716.8 GFLOPS (1:1), confirming that both parts process FP16 and FP32 at the same rate.

The texture rate shows a similar doubling. The 840M reaches 46.40 GTexel/s, while the 820M is at 22.40 GTexel/s. This is precisely double, driven by the 16 TMUs versus 8 TMUs. The pixel rate follows the same pattern: the 840M produces 23.20 GPixel/s against the 820M's 11.20 GPixel/s, again exactly double, reflecting the 8 ROPs versus 4 ROPs. The ray tracing core count doubles from 2 to 4, although no ray tracing benchmark scores are available in the database to quantify the real-world impact.

The boost clock difference contributes a smaller but real advantage. The 840M's 2900 MHz boost is 3.57% higher than the 820M's 2800 MHz. This clock advantage operates multiplicatively with the resource doubling, which is why the FP32, texture rate, and pixel rate figures exceed a strict 2.0x ratio in the FP32 case. The texture and pixel rates land exactly at 2.0x because those metrics are calculated directly from TMU and ROP counts multiplied by clock, and the rounding in the recorded values may obscure the fractional component. The FP32 figure of 1,484.8 GFLOPS versus 716.8 GFLOPS shows the combined effect of the extra shading units and the higher clock more clearly.

The memory bandwidth is system-dependent for both parts, so no direct comparison can be made from the recorded data. The bus interface is identical at PCIe 4.0 x8, meaning the host platform's memory configuration will determine whether the 840M's compute advantage is fully utilized or bottlenecked. In a system with fast dual-channel memory, the 840M's doubled compute resources have more headroom to translate into frame rate or render time improvements. In a system with slower or single-channel memory, both GPUs would be memory-limited, and the 840M's advantages would be partially masked.

The TDP is identical at 15 W for both, which is notable given the 840M's doubled resource count and higher boost clock. The database records no difference in power draw, indicating that the 840M achieves its greater throughput within the same power envelope. This is a meaningful architectural result: the RDNA 3.5 design on 4 nm TSMC allows the 840M to double execution resources without an increase in the listed TDP. The practical thermal behavior may vary by host device, but the recorded specification shows parity.

The release date is identical for both parts, so there is no generational timing advantage. The predecessor is also identical, Navi II IGP, for both. The production status is Active for both, meaning neither part is discontinued or in limited availability per the database records.

In summary, the recorded data shows the Radeon 840M ahead of the Radeon 820M in every compute metric where a direct comparison is possible. The FP32 throughput advantage is the most pronounced at over 2.07x, while the texture rate and pixel rate advantages are exactly 2.0x. The boost clock adds a smaller but consistent edge. The 820M does not win any recorded category; it only matches the 840M in base clock, memory configuration, power, API support, and release timing. The absence of benchmark scores means the real-world performance gap cannot be quantified beyond these specification-derived figures, but the structural doubling of resources in the 840M provides a clear analytical basis for its superior throughput ceiling.