NVIDIA RTX A4000 Mobile vs NVIDIA Tesla K20m Comparison

FAQ

Q: How does the NVIDIA RTX A4000 Mobile compare to the NVIDIA Tesla K20m in overall benchmark scores?

A: The RTX A4000 Mobile has an average benchmark score of 21,379, while the Tesla K20m scores 19,089. The RTX A4000 Mobile sits at the 66th percentile of all GPUs, slightly ahead of the Tesla K20m's 64th percentile.

Q: Which GPU wins in OpenCL performance?

A: The RTX A4000 Mobile dominates OpenCL with a score of 97,178 versus 16,241 for the Tesla K20m, a 498.3% advantage. This is the single largest performance gap between the two in any recorded test.

Q: What about Vulkan performance?

A: The RTX A4000 Mobile scores 73,002 in Vulkan compared to 21,936 for the Tesla K20m. That translates to a 232.8% lead for the Ampere-based mobile part.

Q: Do both GPUs support the same modern APIs?

A: No. The RTX A4000 Mobile supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The Tesla K20m supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175, so the RTX A4000 Mobile has a higher DirectX feature level and a newer Vulkan version.

Q: What are the memory specifications of each card?

A: The RTX A4000 Mobile has 8 GB of GDDR6 on a 256-bit bus with 384.0 GB/s bandwidth. The Tesla K20m has 5 GB of GDDR5 on a 320-bit bus with 208.0 GB/s bandwidth. The RTX A4000 Mobile offers more capacity and nearly double the bandwidth.

Q: Which card has higher shading unit and ray tracing counts?

A: The RTX A4000 Mobile has 5,120 shading units, 40 RT cores, and 160 tensor cores. The Tesla K20m has 2,496 shading units and no RT or tensor cores, reflecting its older Kepler architecture.

Architecture Differences

The NVIDIA RTX A4000 Mobile is built on the Ampere architecture using the GA104 chip, fabricated on Samsung's 8 nm process. The Tesla K20m uses the Kepler architecture with the GK110 chip on TSMC's 28 nm process. The transistor counts reflect this generational gap: the RTX A4000 Mobile packs 17,400 million transistors on a 392 mm² die, achieving a transistor density of 44.4M per mm². The Tesla K20m has 7,080 million transistors on a larger 561 mm² die, with a density of just 12.6M per mm². The RTX A4000 Mobile's smaller and denser die is a direct result of the newer fabrication node.

Clock behavior also differs. The RTX A4000 Mobile has a base clock of 1140 MHz and a boost clock of 1680 MHz, while the Tesla K20m has no recorded base or boost clock in the database. Memory clocks show the RTX A4000 Mobile running at 1500 MHz with 12 Gbps effective, versus 1300 MHz with 5.2 Gbps effective for the Tesla K20m.

Feature support is a major separator. The RTX A4000 Mobile includes 40 RT cores for hardware ray tracing and 160 tensor cores for AI workloads. The Tesla K20m has neither, as Kepler predates those specialized units. The RTX A4000 Mobile also supports DirectX 12 Ultimate (12_2), while the Tesla K20m only reaches DirectX 12 (11_0). Vulkan support is newer on the RTX A4000 Mobile (1.4) compared to the Tesla K20m (1.2.175).

The Tesla K20m is a dual-slot card with 1x 6-pin plus 1x 8-pin power connectors and no display outputs, designed for compute servers. The RTX A4000 Mobile has no power connectors and its display outputs are portable device dependent, reflecting its mobile workstation nature. The Tesla K20m carries a suggested PSU of 550 W, while no such figure exists for the mobile part.

The Verdict

The data points to a clear conclusion: the RTX A4000 Mobile is the superior GPU for nearly every workload measured. It wins both head-to-head benchmarks, and the margins are enormous. In OpenCL the RTX A4000 Mobile is 498.3% ahead, and in Vulkan it is 232.8% ahead. The average benchmark score difference, 21,379 versus 19,089, is smaller but still favors the RTX A4000 Mobile.

The RTX A4000 Mobile should be the choice for anyone needing mobile workstation performance with modern API support, ray tracing, tensor cores, and high memory bandwidth. Its 8 GB GDDR6 memory and 384.0 GB/s bandwidth make it suitable for large datasets and modern rendering workloads. The Tesla K20m, with 5 GB GDDR5 and 208.0 GB/s bandwidth, is a legacy compute accelerator that cannot handle the same workload breadth.

For compute-focused users who require a dual-slot server card with no display outputs, the Tesla K20m has its niche, but its architectural limitations are severe. The lack of RT and tensor cores, lower shading unit count (2,496 vs 5,120), and older DirectX support all point to a product that has been surpassed in every measurable way. The RTX A4000 Mobile also has a higher TDP efficiency, with 115 W versus 225 W, meaning it delivers far more performance per watt.

The verdict is straightforward: the RTX A4000 Mobile wins on performance, features, and efficiency. The Tesla K20m remains a historical data point, not a competitive option.

Specification Differences

| Specification | NVIDIA RTX A4000 Mobile | NVIDIA Tesla K20m |

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

| Architecture | Ampere | Kepler |

| Chip | GA104 | GK110 |

| Process Node | 8 nm (Samsung) | 28 nm (TSMC) |

| Transistors | 17,400 million | 7,080 million |

| Die Size | 392 mm² | 561 mm² |

| Transistor Density | 44.4M / mm² | 12.6M / mm² |

| Base Clock | 1140 MHz | Not recorded |

| Boost Clock | 1680 MHz | Not recorded |

| Memory Clock | 1500 MHz, 12 Gbps effective | 1300 MHz, 5.2 Gbps effective |

| Memory Size | 8 GB | 5 GB |

| Memory Type | GDDR6 | GDDR5 |

| Memory Bus Width | 256 bit | 320 bit |

| Memory Bandwidth | 384.0 GB/s | 208.0 GB/s |

| Shading Units | 5120 | 2496 |

| TMUs | 160 | 208 |

| ROPs | 80 | 40 |

| RT Cores | 40 | None |

| Tensor Cores | 160 | None |

| Pixel Rate | 134.4 GPixel/s | 36.71 GPixel/s |

| Texture Rate | 268.8 GTexel/s | 146.8 GTexel/s |

| FP32 | 17.20 TFLOPS | 3.524 TFLOPS |

| FP16 | 17.20 TFLOPS (1:1) | Not recorded |

| TDP | 115 W | 225 W |

| Slot Width | Not recorded | Dual-slot |

| Power Connectors | None | 1x 6-pin + 1x 8-pin |

| Suggested PSU | Not recorded | 550 W |

| Bus Interface | PCIe 4.0 x16 | PCIe 2.0 x16 |

| Display Outputs | Portable Device Dependent | No outputs |

| DirectX | 12 Ultimate (12_2) | 12 (11_0) |

| Vulkan | 1.4 | 1.2.175 |

| Release Date | 2021-04-11 | 2013-01-04 |

| Launch MSRP | Not recorded | 3,199 USD |

Head-to-Head Benchmarks

Two benchmark tests were recorded for both GPUs, and the RTX A4000 Mobile wins both.

In geekbench_opencl, the RTX A4000 Mobile scores 97,178 against 16,241 for the Tesla K20m. The delta is 498.3%, meaning the RTX A4000 Mobile delivers roughly six times the OpenCL performance. This is the most lopsided result in the comparison and reflects the massive architectural lead of Ampere over Kepler in compute-heavy OpenCL workloads.

In geekbench_vulkan, the RTX A4000 Mobile scores 73,002 versus 21,936 for the Tesla K20m. The delta here is 232.8%. While narrower than the OpenCL gap, it still represents more than a threefold advantage. Vulkan support on the Tesla K20m is limited to version 1.2.175, while the RTX A4000 Mobile supports Vulkan 1.4, which likely contributes to the difference.

The average benchmark scores reinforce these results. The RTX A4000 Mobile averages 21,379 across all recorded tests, while the Tesla K20m averages 19,089. The RTX A4000 Mobile's nearest rivals include the NVIDIA Quadro RTX 5000 (21,629, only 1.2% higher) and the AMD Radeon HD 8970M (21,237, 0.7% lower). The Tesla K20m's nearest rivals include the NVIDIA GeForce RTX 4050 Mobile (19,049, 0.2% lower) and the AMD Radeon RX 6600 (19,036, 0.3% lower). This places the RTX A4000 Mobile in a higher performance tier altogether.

The wins are decisive, with the RTX A4000 Mobile taking 2 wins and the Tesla K20m taking 0. No benchmark in the database favors the older Kepler card.

Where Each One Wins

The RTX A4000 Mobile wins in every category where both cards were measured. Its OpenCL score of 97,178 makes it the clear choice for OpenCL-based compute tasks, including scientific simulation, image processing, and general GPU compute. The 498.3% lead over the Tesla K20m is not a marginal edge; it is a generational leap. Its Vulkan score of 73,002 similarly positions it as the superior option for Vulkan rendering and modern game workloads, with a 232.8% advantage.

The RTX A4000 Mobile also excels in memory-intensive scenarios. With 8 GB of GDDR6 and 384.0 GB/s bandwidth, it can handle larger textures, bigger datasets, and more concurrent memory requests than the Tesla K20m's 5 GB GDDR5 with 208.0 GB/s. The FP32 throughput of 17.20 TFLOPS versus 3.524 TFLOPS means the RTX A4000 Mobile processes single-precision floating point nearly five times faster. The FP16 capability at 17.20 TFLOPS (1:1) adds half-precision compute that the Tesla K20m cannot match at all.

The Tesla K20m does have a few theoretical advantages, though they do not translate into benchmark wins. Its 208 TMUs exceed the RTX A4000 Mobile's 160, which could help in certain texture-heavy workloads. Its 320-bit memory bus is wider than the 256-bit bus of the RTX A4000 Mobile, though the GDDR6 memory speed more than compensates. The dual-slot form factor with 1x 6-pin plus 1x 8-pin connectors indicates it was designed for dedicated server installations, while the RTX A4000 Mobile is a mobile part. For users requiring a card with no display outputs in a dual-slot server configuration, the Tesla K20m fits that specific physical requirement. But in raw performance, the database shows no scenario where the Tesla K20m comes out ahead.

The RTX A4000 Mobile is the winner for virtually all workloads: mobile workstations, OpenCL compute, Vulkan rendering, ray tracing, tensor-based AI tasks, and any application that benefits from modern API support. The Tesla K20m is a legacy compute card with a niche physical profile and no recorded performance wins.