AMD Radeon R9 M395X vs AMD Radeon RX 6600 XT Comparison

FAQ

Q: How much faster is the AMD Radeon RX 6600 XT than the AMD Radeon R9 M395X in Geekbench Metal?

A: The RX 6600 XT scores 88,720 versus 33,953 for the R9 M395X, which is a 61.7% lead for the newer card in that test.

Q: Which GPU has the higher average benchmark score across all tested workloads?

A: The R9 M395X has the higher average benchmark score at 25,891, while the RX 6600 XT averages 24,442. This is despite the RX 6600 XT winning both head-to-head tests.

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

A: The RX 6600 XT's Navi 23 packs 46.7 million transistors per mm², while the R9 M395X's Amethyst chip has only 13.7 million per mm². The RX 6600 XT is built on TSMC's 7 nm process versus 28 nm for the older card.

Q: Does the RX 6600 XT support hardware ray tracing?

A: Yes. The RX 6600 XT has 32 ray accelerators and supports DirectX 12 Ultimate (12_2). The R9 M395X has no ray tracing cores and only supports DirectX 12 (12_0).

Q: How do the memory bandwidth figures compare?

A: The RX 6600 XT delivers 256.0 GB/s over a 128-bit GDDR6 bus, while the R9 M395X provides 160.0 GB/s over a 256-bit GDDR5 bus. The newer card achieves higher bandwidth despite half the bus width.

Q: What is the closest rival to each card according to average benchmark score?

A: The R9 M395X's nearest rival is the AMD FirePro W7100 with a delta of 0.1%, while the RX 6600 XT's nearest rival is the NVIDIA GeForce GTX 1630 with a delta of 0.7%.

Architecture Differences

The R9 M395X and RX 6600 XT represent two completely different eras of AMD GPU design. The older card uses the Amethyst chip based on GCN 3.0 architecture, fabricated on TSMC's 28 nm process. It contains 5,000 million transistors spread across a 366 mm² die, yielding a modest transistor density of 13.7 million per mm². The newer RX 6600 XT uses the Navi 23 chip with RDNA 2.0 architecture, built on TSMC's 7 nm process. It packs 11,060 million transistors into a much smaller 237 mm² die, achieving 46.7 million transistors per mm² — more than three times the density.

Memory architecture tells a similar story of generational change. The R9 M395X uses 8 GB of GDDR5 on a 256-bit bus, producing 160.0 GB/s of bandwidth. The RX 6600 XT also has 8 GB, but uses GDDR6 on a 128-bit bus, yet achieves 256.0 GB/s — a 60% bandwidth advantage. The newer memory technology compensates for the narrower bus. Clock behavior differs too: the R9 M395X has no listed base or boost clock, only a 1250 MHz memory clock (5 Gbps effective), whereas the RX 6600 XT has a 1968 MHz base clock, 2359 MHz game clock, and 2589 MHz boost clock, with memory at 2000 MHz (16 Gbps effective).

The feature set diverges sharply. The RX 6600 XT includes 32 ray tracing cores and supports DirectX 12 Ultimate (12_2), Vulkan 1.4, and has a 2:1 FP16 ratio (21.21 TFLOPS). The R9 M395X has no RT cores, supports DirectX 12 (12_0) and Vulkan 1.2.170, and runs FP16 at a 1:1 ratio (2.961 TFLOPS, same as FP32). The R9 M395X uses a PCIe 3.0 x16 interface and is an MXM module with no power connectors, drawing just 75 W. The RX 6600 XT is a dual-slot card with a PCIe 4.0 x8 interface, requires a single 8-pin power connector, and has a 160 W TDP. The R9 M395X's display outputs are "portable device dependent," while the RX 6600 XT offers 1x HDMI 2.1 and 3x DisplayPort 1.4a.

The Verdict

The data points to a clear generational leap, but not a simple one. The RX 6600 XT wins both head-to-head benchmarks decisively: 61.7% in Geekbench Metal and 77.9% in Geekbench OpenCL. Its raw throughput numbers are dramatically higher — 10.60 TFLOPS FP32 versus 2.961 TFLOPS, 331.4 GTexel/s versus 92.54 GTexel/s, and 165.7 GPixel/s versus 23.14 GPixel/s. If the question is which GPU delivers more performance, the RX 6600 XT is the answer without qualification.

However, the average benchmark scores complicate the picture. The R9 M395X averages 25,891 across all tests, slightly ahead of the RX 6600 XT's 24,442. This suggests the older card has strengths in workloads not captured by the two head-to-head tests. The R9 M395X also sits at the 71st percentile versus the RX 6600 XT's 70th, a marginal difference. For users whose workloads align with the R9 M395X's profile — likely compute-oriented tasks given its GCN heritage — the newer card might not be an automatic upgrade.

The verdict depends on workload. For gaming and modern API support, the RX 6600 XT is the clear choice: it has ray tracing, DirectX 12 Ultimate, higher clock speeds, and vastly better bandwidth. For legacy compute tasks or applications that favor the R9 M395X's specific architecture, the older card remains competitive. The RX 6600 XT also carries a launch MSRP of 379 USD. The R9 M395X has no launch MSRP listed. Both cards are end-of-life, so longevity is not a differentiator.

Specification Differences

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

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

| 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 | — | 1968 MHz |

| Boost Clock | — | 2589 MHz |

| Game Clock | — | 2359 MHz |

| Memory Clock | 1250 MHz (5 Gbps effective) | 2000 MHz (16 Gbps effective) |

| Memory Type | GDDR5 | GDDR6 |

| Memory Bus Width | 256 bit | 128 bit |

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

| Shading Units | 2048 | 2048 |

| TMUs | 128 | 128 |

| ROPs | 32 | 64 |

| RT Cores | — | 32 |

| Pixel Rate | 23.14 GPixel/s | 165.7 GPixel/s |

| Texture Rate | 92.54 GTexel/s | 331.4 GTexel/s |

| FP32 | 2.961 TFLOPS | 10.60 TFLOPS |

| FP16 | 2.961 TFLOPS (1:1) | 21.21 TFLOPS (2:1) |

| TDP | 75 W | 160 W |

| Slot Width | MXM Module | Dual-slot |

| Power Connectors | None | 1x 8-pin |

| Suggested PSU | — | 450 W |

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

| Display Outputs | Portable Device Dependent | 1x HDMI 2.1, 3x DisplayPort 1.4a |

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

| Vulkan | 1.2.170 | 1.4 |

| Release Date | 2015-05-04 | 2021-07-29 |

| Predecessor | Solar System | Navi |

| Successor | Polaris Mobile | Navi III |

Head-to-Head Benchmarks

The two GPUs share only two benchmark results in common, and the RX 6600 XT dominates both. In Geekbench Metal, the RX 6600 XT scores 88,720 against the R9 M395X's 33,953, a 61.7% advantage. This is a massive gap that reflects not just architectural improvements but also the clock speed and bandwidth advantages of the newer card. The R9 M395X's 160.0 GB/s bandwidth and 2.961 TFLOPS FP32 are simply outclassed by the RX 6600 XT's 256.0 GB/s and 10.60 TFLOPS.

Geekbench OpenCL shows an even larger disparity. The RX 6600 XT posts 80,503, while the R9 M395X manages only 17,829 — a 77.9% deficit for the older card. This suggests OpenCL workloads scale particularly well with the RX 6600 XT's architecture, possibly leveraging its higher texture rate (331.4 GTexel/s versus 92.54 GTexel/s) and pixel rate (165.7 GPixel/s versus 23.14 GPixel/s). The R9 M395X has no winning benchmark in the head-to-head comparison; the RX 6600 XT wins both tests, giving it a 2-0 record.

The average benchmark scores tell a different story. The R9 M395X averages 25,891, slightly edging out the RX 6600 XT's 24,442. This means the RX 6600 XT's victories in the two shared tests are not representative of its performance across the broader benchmark suite. The RX 6600 XT has many more benchmark entries — including 3DMark Steel Nomad, multiple PassMark tests, and Geekbench Vulkan — which may drag its average down relative to the focused set of tests available for the R9 M395X.

Where Each One Wins

The RX 6600 XT wins in every directly comparable benchmark, but the nature of those wins reveals its strengths. Its 77.9% OpenCL advantage suggests compute-heavy applications favor the newer architecture. The 61.7% Metal win indicates graphics workloads also benefit substantially. The RX 6600 XT's ray tracing capability, DirectX 12 Ultimate support, and 2:1 FP16 ratio (21.21 TFLOPS) make it the choice for modern gaming and applications that use these features. Its 256.0 GB/s bandwidth and 165.7 GPixel/s pixel rate point to strong performance in high-resolution rendering and texture-heavy scenes.

The R9 M395X wins in efficiency and specific legacy scenarios. Its 75 W TDP is less than half the RX 6600 XT's 160 W, and it requires no power connectors, making it suitable for portable devices with limited power budgets. The MXM module form factor is designed for laptops and compact systems where the dual-slot RX 6600 XT with its 8-pin connector cannot fit. The R9 M395X also has a wider 256-bit memory bus, which some older applications may prefer, even though the RX 6600 XT achieves higher bandwidth with a narrower bus.

The average benchmark scores suggest the R9 M395X holds its own in certain unlisted workloads. Its 71st percentile ranking versus the RX 6600 XT's 70th indicates that across the entire GPU landscape, the older card is not obsolete. For users running software optimized for GCN architecture or constrained by power and form factor requirements, the R9 M395X remains viable. For everyone else, the RX 6600 XT's raw performance — 3.6 times the FP32 throughput, 3.6 times the texture rate, and 7.2 times the pixel rate — makes it the superior choice where power and space are available.