AMD Radeon R9 M395X vs AMD Radeon RX 6600M Comparison

Head-to-Head Benchmarks

The recorded data shows a decisive performance gap between these two mobile GPUs. In the two shared benchmark tests, the AMD Radeon RX 6600M wins both, leaving the R9 M395X with zero wins. The Geekbench Metal test is particularly telling: the RX 6600M scores 92,237 against 33,953 for the R9 M395X, a delta of -63.2% when measured from the RX 6600M's perspective. This means the newer card delivers roughly 2.7 times the Metal score, a massive jump for any workload that leverages Apple's Metal API.

The Geekbench OpenCL result tells a similar story, though the gap is even wider. The RX 6600M posts 67,765 while the R9 M395X manages only 17,829. The delta here is -73.7%, indicating the RX 6600M is approximately 3.8 times faster in this compute-oriented test. For context, the R9 M395X's average benchmark score across all recorded tests is 25,891, placing it at the 71st percentile of all GPUs in the database. The RX 6600M, by contrast, has an average score of 23,273, which lands it at the 68th percentile. This is a curious inversion: the older card holds a higher percentile despite losing both head-to-head tests, because its average is pulled up by fewer, higher-scoring benchmarks while the RX 6600M's average is diluted by a broader test suite that includes lower DirectX and compute results.

Looking at the nearest rivals for each card clarifies the landscape. The R9 M395X sits within 0.6% of the AMD FirePro W7100 (25,856), the AMD FirePro D700 (25,842), and the NVIDIA GeForce RTX 3080 Ti Mobile (25,740), while trailing the AMD Radeon RX 6750 XT (26,011) by 0.5%. These are all desktop-class or high-end mobile parts, which suggests the R9 M395X was a strong performer in its era. The RX 6600M's nearest rivals are a more mixed group: the AMD Radeon R9 M290X matches it almost exactly (23,276 vs 23,273), the AMD Radeon Pro Vega 16 trails by 0.1%, and the NVIDIA P106-100 also trails by 0.1%, while the AMD Radeon AI PRO R9700 leads by 0.2%. None of these deltas exceed 0.2%, meaning the RX 6600M sits in a tightly clustered performance tier.

Architecture Differences

The two GPUs come from fundamentally different design eras. The R9 M395X uses the Amethyst chip built on GCN 3.0 architecture, manufactured on a 28 nm process at TSMC. Its die measures 366 mm² and contains 5,000 million transistors, giving a transistor density of 13.7 million per square millimeter. The RX 6600M uses the Navi 23 chip with RDNA 2.0 architecture, also fabricated by TSMC but on a 7 nm process. The die is much smaller at 237 mm², yet it packs 11,060 million transistors, resulting in a density of 46.7 million per square millimeter. That is more than three times the transistor density, which explains how the newer chip achieves far higher performance from a smaller physical footprint.

Memory configurations also diverge sharply. The R9 M395X pairs 8 GB of GDDR5 on a 256-bit bus, yielding 160.0 GB/s of bandwidth. The RX 6600M also has 8 GB, but it is GDDR6 on a narrower 128-bit bus, yet the bandwidth climbs to 224.0 GB/s. The newer memory technology compensates for the halved bus width, and the effective speed difference is stark: 5 Gbps for the R9 M395X versus 14 Gbps for the RX 6600M. Clock speeds follow a similar pattern. The R9 M395X lists no base or boost clock in the database, but its memory runs at 1250 MHz. The RX 6600M has a base clock of 2068 MHz, a game clock of 2177 MHz, and a boost clock of 2416 MHz, with memory at 1750 MHz.

Compute resources tell a nuanced story. The R9 M395X has 2,048 shading units, 128 texture mapping units, and 32 render output units. The RX 6600M has fewer shading units (1,792) and TMUs (112), but doubles the ROPs to 64. The RX 6600M also introduces 28 ray tracing cores, a feature entirely absent from the R9 M395X. This architectural shift is reflected in the pixel and texture rates: the R9 M395X delivers 23.14 GPixel/s and 92.54 GTexel/s, while the RX 6600M hits 154.6 GPixel/s and 270.6 GTexel/s. The FP32 throughput is 2.961 TFLOPS for the R9 M395X versus 8.659 TFLOPS for the RX 6600M, and the FP16 gap is even larger: 2.961 TFLOPS (1:1 ratio) versus 17.32 TFLOPS (2:1 ratio), meaning the newer card can process half-precision data at nearly six times the rate.

Where Each One Wins

Based strictly on the recorded benchmarks, there is no meaningful category where the R9 M395X comes out ahead. The RX 6600M wins the only two tests that both cards took, and it does so by margins of 63.2% and 73.7%. However, the R9 M395X does hold a higher percentile ranking (71st vs 68th) and a higher average benchmark score (25,891 vs 23,273) when considering all GPUs in the database. This is a statistical artifact: the R9 M395X has only two recorded scores, both from Geekbench, while the RX 6600M has eleven recorded scores across multiple test suites, including several Passmark tests where it posts low numbers (e.g., 52 in Passmark DirectX 12, 87 in DirectX 10, 136 in DirectX 11, 184 in DirectX 9). These low DirectX scores drag down the average despite the GPU being clearly superior in compute and Metal workloads.

For users who prioritize Metal performance, the RX 6600M is the obvious choice. Its 92,237 Metal score versus 33,953 for the R9 M395X represents a 2.7x advantage. For OpenCL compute, the RX 6600M's 67,765 versus 17,829 is a 3.8x advantage. The RX 6600M also offers ray tracing support through its 28 RT cores, which the R9 M395X lacks entirely. The newer card supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the R9 M395X is limited to DirectX 12 (12_0) and Vulkan 1.2.170. The RX 6600M also has a higher TDP of 100 W compared to 75 W for the R9 M395X, which suggests it can sustain higher clocks under load, though both are mobile parts with no external power connectors.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon R9 M395X has an average benchmark score of 25,891, while the AMD Radeon RX 6600M has an average of 23,273. However, this is based on different numbers of recorded tests: two for the R9 M395X and eleven for the RX 6600M.

Q: How much faster is the RX 6600M in Geekbench Metal?

A: The RX 6600M scores 92,237 versus 33,953 for the R9 M395X, representing a 63.2% lead when measured from the RX 6600M's perspective. The RX 6600M is roughly 2.7 times faster in this test.

Q: Does the R9 M395X support ray tracing?

A: No. The R9 M395X has no ray tracing cores listed in the database. The RX 6600M has 28 ray tracing cores.

Q: What are the memory bandwidth figures for both cards?

A: The R9 M395X has 160.0 GB/s bandwidth using 8 GB of GDDR5 on a 256-bit bus. The RX 6600M has 224.0 GB/s bandwidth using 8 GB of GDDR6 on a 128-bit bus.

Q: Which card has more shading units?

A: The R9 M395X has 2,048 shading units, while the RX 6600M has 1,792. Despite having fewer shading units, the RX 6600M achieves much higher FP32 throughput (8.659 TFLOPS vs 2.961 TFLOPS).

Q: How do the nearest rivals compare for each card?

A: The R9 M395X is within 0.6% of the AMD FirePro W7100, AMD FirePro D700, and NVIDIA GeForce RTX 3080 Ti Mobile, while trailing the AMD Radeon RX 6750 XT by 0.5%. The RX 6600M is within 0.2% of the AMD Radeon R9 M290X, AMD Radeon Pro Vega 16, NVIDIA P106-100, and AMD Radeon AI PRO R9700.

The Verdict

The data points overwhelmingly toward the AMD Radeon RX 6600M for any modern workload. It wins both recorded head-to-head benchmarks by wide margins, offers ray tracing support, supports newer API versions (DirectX 12 Ultimate and Vulkan 1.4), and delivers dramatically higher compute throughput. The R9 M395X, while holding a higher percentile ranking in the overall database, simply cannot compete in raw performance: its 2.961 TFLOPS FP32 is less than one-third of the RX 6600M's 8.659 TFLOPS, and its FP16 output is less than one-sixth.

The R9 M395X does have one practical advantage: lower power consumption at 75 W versus 100 W for the RX 6600M. For systems with strict thermal or power budgets, the older card might be preferable, but this comes at a steep performance cost. The R9 M395X's 256-bit memory bus and GDDR5 might appeal to those who value wider buses, but the RX 6600M's GDDR6 on a 128-bit bus still delivers 40% more bandwidth (224.0 GB/s vs 160.0 GB/s). The R9 M395X is end-of-life, as is the RX 6600M, but the newer card represents a far more capable platform for gaming, compute, and API support. Users who need maximum Metal or OpenCL performance, or who want ray tracing, should choose the RX 6600M without hesitation. Users constrained to 75 W or who only run legacy DirectX 11 workloads might still find the R9 M395X adequate, but the recorded data shows no scenario where it wins a benchmark.

Specification Differences

| Specification | AMD Radeon R9 M395X | AMD Radeon RX 6600M |

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

| Series | None listed | Radeon RX 6000 series |

| Chip | Amethyst | Navi 23 |

| Architecture | GCN 3.0 | RDNA 2.0 |

| Generation | Gem System (R9 M300) | Navi Mobile (RX 6000M) |

| Process Node | 28 nm | 7 nm |

| Transistors | 5,000 million | 11,060 million |

| Die Size | 366 mm² | 237 mm² |

| Transistor Density | 13.7M / mm² | 46.7M / mm² |

| Base Clock | Not listed | 2068 MHz |

| Boost Clock | Not listed | 2416 MHz |

| Game Clock | Not listed | 2177 MHz |

| Memory Clock | 1250 MHz, 5 Gbps effective | 1750 MHz, 14 Gbps effective |

| Memory Type | GDDR5 | GDDR6 |

| Memory Bus Width | 256 bit | 128 bit |

| Memory Bandwidth | 160.0 GB/s | 224.0 GB/s |

| Shading Units | 2048 | 1792 |

| TMUs | 128 | 112 |

| ROPs | 32 | 64 |

| RT Cores | None | 28 |

| Pixel Rate | 23.14 GPixel/s | 154.6 GPixel/s |

| Texture Rate | 92.54 GTexel/s | 270.6 GTexel/s |

| FP32 Performance | 2.961 TFLOPS | 8.659 TFLOPS |

| FP16 Performance | 2.961 TFLOPS (1:1) | 17.32 TFLOPS (2:1) |

| TDP | 75 W | 100 W |

| Slot Width | MXM Module | IGP |

| Bus Interface | PCIe 3.0 x16 | PCIe 4.0 x8 |

| DirectX Support | 12 (12_0) | 12 Ultimate (12_2) |

| Vulkan Support | 1.2.170 | 1.4 |

| Release Date | 2015-05-04 | 2021-05-30 |

| Predecessor | Solar System | Polaris Mobile |

| Successor | Polaris Mobile | None listed |