AMD Radeon R9 M395X vs AMD Radeon RX 6800S Comparison

# AMD Radeon R9 M395X vs AMD Radeon RX 6800S

The AMD Radeon R9 M395X and AMD Radeon RX 6800S represent two vastly different eras of mobile graphics, separated by seven years of architectural evolution. The R9 M395X, built on GCN 3.0 and a 28 nm process, was designed for high-end gaming laptops in 2015, while the RX 6800S, based on RDNA 2.0 and a 7 nm process, targeted premium thin-and-light gaming machines in 2022. The benchmark data reveals a decisive generational leap: the RX 6800S delivers roughly 2.5× the Metal score and over 4× the OpenCL score of the older part, yet both cards surprisingly sit within 2 percentile points of each other in overall GPU standings.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon R9 M395X posts an average benchmark score of 25,891, while the AMD Radeon RX 6800S averages 24,063. Despite the RX 6800S winning both head-to-head tests, the R9 M395X holds a 1,828-point advantage in average score, placing it in the 71st percentile versus the 69th percentile for the RX 6800S.

Q: How much faster is the RX 6800S in Geekbench Metal?

A: The RX 6800S scores 85,256 in Geekbench Metal compared to 33,953 for the R9 M395X, a delta of -60.2% from the RX 6800S perspective. This means the RX 6800S is approximately 151% faster than the R9 M395X in this specific test.

Q: What is the transistor density difference between the two GPUs?

A: The R9 M395X packs 5,000 million transistors on a 366 mm² die, yielding 13.7 million transistors per mm². The RX 6800S crams 11,060 million transistors onto a smaller 237 mm² die, achieving 46.7 million transistors per mm² — roughly 3.4× the density of the older chip.

Q: Do both GPUs support DirectX 12?

A: Yes, both support DirectX 12, but at different feature levels. The R9 M395X supports DirectX 12 (12_0), while the RX 6800S supports DirectX 12 Ultimate (12_2), which includes additional features like hardware ray tracing.

Q: Which GPU has higher memory bandwidth?

A: The RX 6800S offers 256.0 GB/s bandwidth using GDDR6 memory on a 128-bit bus, while the R9 M395X provides 160.0 GB/s via GDDR5 on a 256-bit bus. The RX 6800S achieves 60% more bandwidth despite a narrower bus.

Q: How do the FP32 compute figures compare?

A: The R9 M395X delivers 2.961 TFLOPS of FP32 performance, while the RX 6800S reaches 8.602 TFLOPS — nearly 2.9× higher. The RX 6800S also supports FP16 at 17.20 TFLOPS (2:1 rate), whereas the R9 M395X manages only 2.961 TFLOPS with a 1:1 FP16 ratio.

Architecture Differences

The architectural gulf between these two mobile GPUs is substantial. The R9 M395X uses the Amethyst chip built on GCN 3.0, a design that debuted with the R9 M300 generation. It employs a 28 nm TSMC process, placing 5,000 million transistors across a 366 mm² die. The RX 6800S, by contrast, leverages the Navi 23 chip on RDNA 2.0, manufactured on TSMC's 7 nm node, fitting 11,060 million transistors into a 237 mm² package. The process shrink from 28 nm to 7 nm accounts for the dramatic density improvement — from 13.7M to 46.7M transistors per mm².

Both GPUs share identical shading unit counts (2,048) and TMU counts (128), but the similarities end there. The R9 M395X has 32 ROPs, while the RX 6800S doubles that to 64 ROPs. The RX 6800S also introduces 32 dedicated ray tracing cores, a feature entirely absent from the GCN 3.0 design. Memory technology differs fundamentally: the R9 M395X uses GDDR5 at 1,250 MHz (5 Gbps effective) on a 256-bit bus, while the RX 6800S uses GDDR6 at 2,000 MHz (16 Gbps effective) on a 128-bit bus.

The RX 6800S features a base clock of 1,800 MHz, a game clock of 1,975 MHz, and a boost clock of 2,100 MHz — the R9 M395X has no listed base or boost clocks, only a memory clock. API support diverges as well: the RX 6800S supports Vulkan 1.4 and DirectX 12 Ultimate, while the R9 M395X offers Vulkan 1.2.170 and DirectX 12 (12_0). Power envelopes differ notably, with the R9 M395X rated at 75 W TDP and the RX 6800S at 100 W TDP, reflecting the performance gap.

Head-to-Head Benchmarks

The head-to-head data contains only two shared benchmark tests, both of which the RX 6800S wins decisively. In Geekbench Metal, the RX 6800S scores 85,256 against the R9 M395X's 33,953. The delta of -60.2% (expressed from the RX 6800S's perspective) translates to the newer card being roughly 2.5× faster. This is a massive generational improvement, driven by the combination of higher clock speeds, doubled ROPs, and more efficient RDNA 2.0 architecture.

In Geekbench OpenCL, the gap widens even further. The RX 6800S posts 73,202, while the R9 M395X manages only 17,829 — a delta of -75.6%, meaning the RX 6800S is over 4× faster. OpenCL workloads often scale with raw compute throughput, and the RX 6800S's 8.602 TFLOPS FP32 versus 2.961 TFLOPS for the R9 M395X aligns with this result. The RX 6800S wins both head-to-head tests (2 wins, 0 losses), establishing a clear performance hierarchy.

However, the broader benchmark landscape tells a more nuanced story. The R9 M395X's average score of 25,891 actually exceeds the RX 6800S's 24,063. This discrepancy likely stems from the older card being included in more legacy benchmark suites, while the RX 6800S's additional tests (3DMark Steel Nomad, PassMark variants, Vulkan) may pull its average down. The R9 M395X's nearest rival is the AMD Radeon RX 6750 XT (26,011, -0.5%), while the RX 6800S sits closest to the NVIDIA GeForce RTX 2080 SUPER (24,170, -0.4%).

Specification Differences

| Specification | R9 M395X | RX 6800S |

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

| Architecture | GCN 3.0 | RDNA 2.0 |

| 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 | None listed | 1800 MHz |

| Boost Clock | None listed | 2100 MHz |

| Game Clock | None listed | 1975 MHz |

| Memory Type | GDDR5 | GDDR6 |

| Memory Clock | 1250 MHz / 5 Gbps | 2000 MHz / 16 Gbps |

| Memory Bus | 256 bit | 128 bit |

| Memory Bandwidth | 160.0 GB/s | 256.0 GB/s |

| ROPs | 32 | 64 |

| RT Cores | None | 32 |

| FP16 Performance | 2.961 TFLOPS (1:1) | 17.20 TFLOPS (2:1) |

| FP32 Performance | 2.961 TFLOPS | 8.602 TFLOPS |

| Pixel Rate | 23.14 GPixel/s | 134.4 GPixel/s |

| Texture Rate | 92.54 GTexel/s | 268.8 GTexel/s |

| 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 | 2022-01-03 |

The Verdict

The data paints a clear picture: the RX 6800S is the superior performer in every head-to-head comparison, delivering 2.5× the Metal score and 4× the OpenCL score of the R9 M395X. Its architectural advantages — 7 nm process, doubled ROPs, ray tracing cores, faster memory, and nearly 3× the FP32 throughput — make it the obvious choice for modern workloads. The RX 6800S also supports newer API versions (DirectX 12 Ultimate, Vulkan 1.4), future-proofing it for contemporary games and applications.

That said, the R9 M395X holds a higher average benchmark score (25,891 vs. 24,063) and better percentile ranking (71st vs. 69th), suggesting it performs well in legacy benchmarks where its 256-bit memory bus and GCN architecture remain competitive. Its lower TDP (75 W vs. 100 W) also makes it more power-efficient in absolute terms, though this is partly offset by the RX 6800S's superior performance-per-watt given its massive compute advantage.

For a user prioritizing raw performance, modern API support, and ray tracing capability, the RX 6800S is the clear winner. For those constrained by power budgets or running older software that favors GCN 3.0, the R9 M395X remains a viable option, but it is an end-of-life product with no path forward for next-generation features.

Where Each One Wins

AMD Radeon RX 6800S wins in every modern workload category. Its 8.602 TFLOPS FP32 and 17.20 TFLOPS FP16 performance make it ideal for compute-heavy tasks like machine learning inference, video encoding, and 3D rendering. The 32 ray tracing cores enable hardware-accelerated ray tracing in supported games, a feature the R9 M395X cannot offer. The 256.0 GB/s memory bandwidth, despite the narrower 128-bit bus, supports high-resolution textures and fast data transfers. The RX 6800S also excels in DirectX 12 Ultimate and Vulkan 1.4 workloads, making it the choice for current-generation gaming and professional applications. Its 134.4 GPixel/s pixel rate and 268.8 GTexel/s texture rate are 5.8× and 2.9× higher, respectively, than the older card.

AMD Radeon R9 M395X retains advantages in specific areas. Its higher average benchmark score (25,891) and better percentile ranking (71st vs. 69th) suggest it performs relatively better in the aggregate benchmark database, likely due to strong showings in legacy DirectX and OpenGL tests. The 256-bit memory bus provides lower latency per byte transferred, which can benefit certain tightly-coupled compute workloads. Its 75 W TDP is 25% lower than the RX 6800S, making it preferable for ultra-portable designs or systems with stricter thermal limits. The R9 M395X also carries the "Gem System (R9 M300)" generation lineage, which may have optimized drivers for older operating systems and applications that newer hardware no longer prioritizes. For users running software from the 2015 era, the R9 M395X's compatibility and stability in those environments is a practical advantage, even if its raw numbers lag far behind.