AMD Radeon RX 6800 XT vs NVIDIA Tesla M40 Comparison

The Verdict

The data separates these two GPUs decisively, with the AMD Radeon RX 6800 XT winning both head-to-head benchmark comparisons. In Geekbench OpenCL, the RX 6800 XT scores 171,304 against the Tesla M40's 39,192, a 337.1% advantage. The Vulkan gap is similarly lopsided: 136,875 versus 44,602, a 206.9% lead. The average benchmark scores reinforce the hierarchy — the RX 6800 XT averages 48,477 across its benchmark suite, while the Tesla M40 averages 41,897. Both cards sit in similar overall percentile territory (85th for AMD, 83rd for NVIDIA), but that masks the reality that the M40's percentile comes from a different, smaller benchmark set.

The RX 6800 XT is the clear pick for any workload involving modern APIs, higher resolutions, or compute tasks that leverage Vulkan or OpenCL. The Tesla M40, with its Maxwell architecture and no display outputs, is strictly a compute-oriented relic. The data does not support choosing the M40 for any measured workload. Its only theoretical advantage lies in its 250 W TDP versus the RX 6800 XT's 300 W, but even that is offset by the M40's drastically lower performance. For anyone selecting between these two, the RX 6800 XT wins on every benchmark measured. The M40's 83rd percentile placement, achieved with just two benchmarks, does not compensate for its 337% deficit in OpenCL and 207% deficit in Vulkan.

Architecture Differences

The architectural gap between these two cards spans several generations. The RX 6800 XT uses the Navi 21 chip on RDNA 2.0 architecture, built on a 7 nm TSMC process with 26,800 million transistors on a 520 mm² die. The Tesla M40 uses the GM200 chip on Maxwell 2.0 architecture, built on a 28 nm TSMC process with 8,000 million transistors on a larger 601 mm² die. The transistor density tells the story: 51.5 million transistors per mm² for AMD versus 13.3 million per mm² for NVIDIA. This is a 7 nm versus 28 nm process gap that explains much of the performance difference.

The RX 6800 XT packs 4,608 shading units, 288 texture mapping units, 128 ROPs, and 72 ray tracing cores. The Tesla M40 has 3,072 shading units, 192 TMUs, and 96 ROPs, with no ray tracing cores. Clock speeds differ substantially: the RX 6800 XT runs at a base of 1825 MHz, boosting to 2250 MHz, with a game clock of 2015 MHz. The Tesla M40 runs at 948 MHz base and 1112 MHz boost. The AMD card also supports DirectX 12 Ultimate (12_2), while the M40 tops out at DirectX 12 (12_1). Both support OpenGL 4.6 and Vulkan 1.4, but the RX 6800 XT's newer architecture brings hardware ray tracing and a 2:1 FP16 ratio (41.47 TFLOPS FP16 versus 20.74 TFLOPS FP32), while the M40 has no FP16 figures listed.

Memory architectures differ as well. The RX 6800 XT uses 16 GB of GDDR6 on a 256-bit bus with 512.0 GB/s bandwidth. The Tesla M40 uses 12 GB of GDDR5 on a 384-bit bus with 288.4 GB/s bandwidth. The effective memory clock is 16 Gbps for AMD versus 6 Gbps for NVIDIA. The RX 6800 XT also has a PCIe 4.0 x16 interface, while the M40 uses PCIe 3.0 x16.

Head-to-Head Benchmarks

The two head-to-head benchmarks available are Geekbench OpenCL and Geekbench Vulkan. Both are decisive wins for the RX 6800 XT. In OpenCL, the AMD card scores 171,304 against the M40's 39,192 — a 337.1% delta. This is not a marginal edge; it is a four-fold performance gap. The Vulkan result is less extreme but still one-sided: 136,875 versus 44,602, a 206.9% delta, meaning the RX 6800 XT delivers roughly three times the Vulkan performance.

The broader benchmark data adds context. The RX 6800 XT's individual scores include 3DMark Steel Nomad DX12 at 3,689, Geekbench Metal at 181,337, Passmark G3D at 24,980, and Passmark GPU Compute at 13,245. The Tesla M40 only has the two Geekbench results listed, which limits direct comparison. However, the average benchmark scores — 48,477 for AMD versus 41,897 for NVIDIA — suggest that even in a broader test suite, the RX 6800 XT maintains a lead. The 3DMark Steel Nomad score is particularly telling, as it represents a modern DirectX 12 workload that the Maxwell-based M40 cannot run at comparable efficiency. The M40's 83rd percentile ranking, achieved with just two benchmarks, looks less impressive when its nearest rivals include the RTX 3080 Ti (1.7% faster) and RX 7650 GRE (1.9% faster). The RX 6800 XT's nearest rivals, by contrast, include the RTX 5070 Ti (3% slower) and RX Vega 64 (3% slower), placing it in more modern company.

FAQ

Q: Which GPU has higher raw compute throughput?

A: The RX 6800 XT delivers 20.74 TFLOPS FP32, while the Tesla M40 delivers 6.832 TFLOPS FP32 — a three-fold difference. The AMD card also offers 41.47 TFLOPS FP16 (2:1 ratio), while the M40 has no FP16 figure listed.

Q: Does the Tesla M40 support display outputs?

A: No. The M40 lists "No outputs" for display connectivity. The RX 6800 XT includes 1x HDMI 2.1, 2x DisplayPort 1.4a, and 1x USB Type-C.

Q: How do their memory subsystems compare?

A: The RX 6800 XT has 16 GB GDDR6 on a 256-bit bus with 512.0 GB/s bandwidth and 16 Gbps effective memory clock. The Tesla M40 has 12 GB GDDR5 on a 384-bit bus with 288.4 GB/s bandwidth and 6 Gbps effective memory clock.

Q: Which card has better Vulkan performance?

A: The RX 6800 XT scores 136,875 in Geekbench Vulkan versus 44,602 for the Tesla M40, a 206.9% advantage. Both support Vulkan 1.4.

Q: What are the power requirements?

A: The RX 6800 XT has a 300 W TDP with a suggested 700 W PSU and 2x 8-pin connectors. The Tesla M40 has a 250 W TDP with a suggested 600 W PSU and a single 8-pin EPS connector. Both are dual-slot cards of identical length (267 mm).

Q: How do their overall benchmark averages compare?

A: The RX 6800 XT averages 48,477 across its benchmark suite, while the Tesla M40 averages 41,897. The AMD card ranks in the 85th percentile of all GPUs; the M40 ranks in the 83rd.

Where Each One Wins

The RX 6800 XT wins every measured benchmark category. In OpenCL compute, its 337.1% lead over the M40 makes it the only reasonable choice for general-purpose GPU compute workloads that use that API. In Vulkan, the 206.9% advantage similarly dominates. The AMD card also supports DirectX 12 Ultimate (12_2), which the M40 cannot claim, and includes hardware ray tracing cores that the M40 lacks entirely. For gaming or any graphics workload, the RX 6800 XT is the only viable option between the two.

The Tesla M40's only "wins" are qualitative. It has a lower TDP (250 W versus 300 W) and a lower suggested PSU (600 W versus 700 W). Its 384-bit memory bus is wider, though its overall bandwidth is lower. It also has a larger die (601 mm² versus 520 mm²) despite being on an older process. For a system with strict power limits, the M40 draws less — but the performance penalty is enormous. The M40's 83rd percentile ranking, achieved with only two benchmark scores, suggests it remains competitive within a narrow compute niche, but the head-to-head data shows it is outclassed by the RX 6800 XT in every measurable way. The RX 6800 XT's nearest rivals include the RTX 5070 Ti (3% slower) and RX Vega 64 (3% slower), while the M40's nearest rivals include the RTX 3080 Ti (1.7% faster) and RX 7650 GRE (1.9% faster) — placing the M40 in older, slower company.

Specification Differences

| Specification | AMD Radeon RX 6800 XT | NVIDIA Tesla M40 |

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

| Architecture | RDNA 2.0 | Maxwell 2.0 |

| Process node | 7 nm | 28 nm |

| Transistors | 26,800 million | 8,000 million |

| Die size | 520 mm² | 601 mm² |

| Transistor density | 51.5M / mm² | 13.3M / mm² |

| Base clock | 1825 MHz | 948 MHz |

| Boost clock | 2250 MHz | 1112 MHz |

| Memory clock | 16 Gbps effective | 6 Gbps effective |

| Memory size | 16 GB | 12 GB |

| Memory type | GDDR6 | GDDR5 |

| Memory bus width | 256 bit | 384 bit |

| Memory bandwidth | 512.0 GB/s | 288.4 GB/s |

| Shading units | 4608 | 3072 |

| TMUs | 288 | 192 |

| ROPs | 128 | 96 |

| RT cores | 72 | None |

| Pixel rate | 288.0 GPixel/s | 106.8 GPixel/s |

| Texture rate | 648.0 GTexel/s | 213.5 GTexel/s |

| FP32 | 20.74 TFLOPS | 6.832 TFLOPS |

| FP16 | 41.47 TFLOPS (2:1) | None listed |

| TDP | 300 W | 250 W |

| Power connectors | 2x 8-pin | 8-pin EPS |

| Suggested PSU | 700 W | 600 W |

| Bus interface | PCIe 4.0 x16 | PCIe 3.0 x16 |

| Display outputs | 1x HDMI 2.1, 2x DisplayPort 1.4a, 1x USB Type-C | No outputs |

| DirectX support | 12 Ultimate (12_2) | 12 (12_1) |

| Release date | 2020-10-27 | 2015-11-09 |

| Predecessor | Navi | Tesla Kepler |

| Successor | Navi III | Tesla Pascal |

| Launch MSRP | 649 USD | None listed |