AMD Radeon R7 M340 vs AMD Radeon R8 M445DX Comparison

AMD Radeon R7 M340 and AMD Radeon R8 M445DX are both end-of-life mobile graphics solutions built on the same fundamental silicon, yet they target different use cases within the laptop market. The R7 M340 is a discrete part with its own dedicated video memory, while the R8 M445DX is a hybrid solution that relies on system memory. Benchmark data shows the R7 M340 holds a slim but consistent performance edge in the only directly comparable test, making it the more capable option for users who need a guaranteed level of graphics throughput.

Where Each One Wins

The AMD Radeon R7 M340 wins in pure compute performance based on available benchmark results. In the Geekbench OpenCL test, the R7 M340 scores 4932 points against 4727 points for the R8 M445DX. This 4.3% advantage makes the R7 M340 the clear choice for any workload that stresses raw GPU compute, such as general-purpose processing or older game titles that rely heavily on shader throughput. The R7 M340 also holds a higher average benchmark score of 5063 compared to the R8 M445DX's 4727, reinforcing its position as the faster part overall.

The AMD Radeon R8 M445DX, conversely, has no benchmark wins in the head-to-head data. Its single recorded score places it in the 27th percentile of all GPUs, while the R7 M340 sits at the 30th percentile. Where the R8 M445DX potentially wins is in system integration — it uses the system shared memory architecture, which means it does not require a separate VRAM allocation. This makes it a more flexible option for thin-and-light laptops where space and power are at a premium, and where the performance gap is less critical than the simplicity of a unified memory pool. For users who prioritize a compact system footprint over peak graphics output, the R8 M445DX's design philosophy holds appeal, but on raw numbers, the R7 M340 is the winner.

Architecture Differences

Both GPUs share the same fundamental architecture: GCN 3.0, built on a 28 nm process at TSMC. The chip is Meso for both, with an identical transistor count of 1,550 million and a die size of 125 mm². This means the core compute resources are identical — 320 shading units, 20 texture mapping units, and 8 ROPs. The pixel rate is 8.168 GPixel/s and the texture rate is 20.42 GTexel/s for both parts. FP32 performance is also the same at 653.4 GFLOPS, with FP16 running at 653.4 GFLOPS (1:1). Both support DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.2.170.

The key divergence lies in memory architecture. The R7 M340 uses a dedicated 2 GB DDR3 pool on a 64-bit bus, yielding a fixed bandwidth of 16.00 GB/s and a memory clock of 1000 MHz (2 Gbps effective). The R8 M445DX, however, uses "System Shared" memory — the size, type, and bus width are all shared with the host system, and bandwidth is "System Dependent." This is a fundamental difference in how each GPU accesses data. The R7 M340's dedicated VRAM ensures predictable memory performance, while the R8 M445DX's performance will vary based on the system's memory configuration and workload.

Clock speeds differ as well. The R7 M340 has a base clock of 943 MHz and a boost clock of 1021 MHz. The R8 M445DX starts lower at 780 MHz base but also boosts to 1021 MHz. This lower base clock suggests the R8 M445DX is tuned for lower sustained power draw, while the R7 M340 can maintain a higher clock under load. The R8 M445DX is an IGP (integrated graphics processor) with a slot width of "IGP" and a bus interface of "IGP," whereas the R7 M340 uses a PCIe 3.0 x8 interface. This reinforces the R8 M445DX's role as an integrated solution rather than a discrete add-in card.

Head-to-Head Benchmarks

The only direct benchmark comparison available is Geekbench OpenCL, where the AMD Radeon R7 M340 scores 4932 against the AMD Radeon R8 M445DX's 4727. This gives the R7 M340 a 4.3% win. While this margin is modest, it is consistent with the R7 M340's higher base clock and dedicated memory bandwidth. The R7 M340 also has a Vulkan score of 5193, though no comparable Vulkan result exists for the R8 M445DX, so a cross-API comparison is not possible from the data.

Looking at the average benchmark scores, the R7 M340 averages 5063, which places it exactly level with the AMD Radeon R7 240 (deltaPct 0) and slightly ahead of the AMD FirePro W4170M by 0.6% and the AMD Radeon R5 M430 by 0.9%. The R8 M445DX averages 4727, which puts it 0.5% behind the AMD Radeon R5 M335 and 1.3% behind the AMD Radeon R5 M255. Notably, the R8 M445DX is 0.9% ahead of the NVIDIA Quadro P400. In percentage terms, the R7 M340's 4.3% lead over the R8 M445DX is smaller than the gap between the R8 M445DX and some of its own rivals, indicating that both parts are in a similar performance class, but the R7 M340 consistently comes out on top where data exists.

FAQ

Q: Which GPU has better raw compute performance?

A: The AMD Radeon R7 M340. In Geekbench OpenCL, it scores 4932 versus 4727 for the R8 M445DX, a 4.3% advantage. The R7 M340 also has a higher average benchmark score of 5063 compared to 4727.

Q: Do both GPUs use the same underlying chip?

A: Yes. Both use the Meso chip on GCN 3.0 architecture, built on a 28 nm process at TSMC. They share identical transistor counts (1,550 million), die size (125 mm²), shading units (320), TMUs (20), and ROPs (8).

Q: How does memory differ between the two?

A: The R7 M340 has 2 GB of dedicated DDR3 memory on a 64-bit bus with 16.00 GB/s bandwidth. The R8 M445DX uses System Shared memory, where size, type, and bus width are system-dependent, and bandwidth is listed as "System Dependent."

Q: What are the clock speed differences?

A: The R7 M340 runs at a base clock of 943 MHz and boosts to 1021 MHz. The R8 M445DX has a lower base clock of 780 MHz but also boosts to 1021 MHz.

Q: Which GPU is better for a laptop with limited space?

A: The R8 M445DX, because it is an IGP with no dedicated memory or PCIe interface. Its bus interface is listed as "IGP," making it more suitable for compact, integrated designs. The R7 M340 uses a PCIe 3.0 x8 interface and dedicated VRAM, requiring more board space.

Q: How do these GPUs compare to their nearest rivals?

A: The R7 M340 is exactly level with the AMD Radeon R7 240 (0% delta) and 0.6% ahead of the AMD FirePro W4170M. The R8 M445DX is 0.5% behind the AMD Radeon R5 M335 and 0.9% ahead of the NVIDIA Quadro P400.

Specification Differences

| Specification | AMD Radeon R7 M340 | AMD Radeon R8 M445DX |

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

| Generation | Gem System (R7 M300) | Gem System Hybrid (Rx M400) |

| Base Clock | 943 MHz | 780 MHz |

| Boost Clock | 1021 MHz | 1021 MHz |

| Memory Clock | 1000 MHz (2 Gbps effective) | System Shared |

| Memory Size | 2 GB | System Shared |

| Memory Type | DDR3 | System Shared |

| Memory Bus Width | 64 bit | System Shared |

| Memory Bandwidth | 16.00 GB/s | System Dependent |

| Bus Interface | PCIe 3.0 x8 | IGP |

| Slot Width | Not specified | IGP |

| Display Outputs | Not specified | Portable Device Dependent |

| Release Date | 2015-05-04 | 2016-05-14 |

| Predecessor | Solar System | Not specified |

| Successor | Polaris Mobile | Not specified |

| Geekbench OpenCL | 4932 | 4727 |

| Geekbench Vulkan | 5193 | Not available |

| Avg Benchmark Score | 5063 | 4727 |

| Percentile vs All GPUs | 30 | 27 |

The Verdict

The data points decisively to the AMD Radeon R7 M340 as the stronger performer. It wins the only direct benchmark comparison, holds a higher average score, and sits at a higher percentile among all GPUs. The R7 M340's dedicated 2 GB of DDR3 memory and fixed 16.00 GB/s bandwidth provide predictable performance, while its higher base clock of 943 MHz (versus 780 MHz) gives it a sustained compute advantage. For any user whose priority is graphics output — whether for gaming, media encoding, or general compute — the R7 M340 is the clear pick.

The AMD Radeon R8 M445DX, however, serves a different purpose. Its System Shared memory and IGP designation make it a lower-cost integration option for laptops that do not want to allocate board space for discrete VRAM. It still delivers the same boost clock of 1021 MHz and identical FP32 throughput of 653.4 GFLOPS, so it is not a slouch. But its performance is system-dependent, and the data shows it trails the R7 M340 by 4.3% in OpenCL. Choose the R8 M445DX only if system integration is your primary constraint; otherwise, the R7 M340 is the faster, more reliable option.