NVIDIA GeForce RTX 4090 D vs NVIDIA L20 Comparison

The NVIDIA L20 and NVIDIA GeForce RTX 4090 D are both built on the Ada Lovelace architecture, but they target entirely different corners of the market. The L20 is a server-oriented card with a massive memory pool, while the RTX 4090 D is a consumer flagship with raw compute muscle. Benchmark data shows the RTX 4090 D wins both shared head-to-head tests, but the L20’s design philosophy points toward professional workloads where capacity matters more than peak throughput. This analysis breaks down where each card excels, what separates them internally, and which one the data actually supports for a given task.

Where Each One Wins

The RTX 4090 D wins on raw performance in the two benchmarks both cards share. In Geekbench OpenCL, it scores 278,621 against the L20’s 274,276, a margin of just 1.6%. That is a narrow victory, but it is consistent. The gap widens significantly in Geekbench Vulkan, where the RTX 4090 D posts 246,941 versus 228,018 for the L20, a 7.7% advantage. If your workload scales with compute units and clock speed, the RTX 4090 D is the clear pick based on these results.

The L20 wins on capacity and efficiency. It carries 48 GB of GDDR6 memory, double the 24 GB on the RTX 4090 D, and does so with a lower power envelope. The L20 has a TDP of 275 W and fits in a dual-slot form factor, while the RTX 4090 D draws 425 W and occupies a triple-slot cooler. The data indicates the L20 is built for environments where memory footprint and thermal density are constraints — think large datasets or models that need to stay resident on the GPU. It also holds a 99th percentile ranking among all GPUs, compared to the 98th for the RTX 4090 D, suggesting that in the broader database context, the L20’s aggregate score positions it slightly higher relative to the entire field.

Architecture Differences

Both cards share the same AD102 chip, TSMC 5 nm process, and a die size of 609 mm² with 76,300 million transistors. The transistor density is identical at 125.3M per mm². The divergence starts with the configuration of the silicon. The RTX 4090 D enables more of the chip’s resources: 14,592 shading units, 456 TMUs, 176 ROPs, 114 RT cores, and 456 tensor cores. The L20 is cut down to 11,776 shading units, 368 TMUs, 128 ROPs, 92 RT cores, and 368 tensor cores. That is a substantial reduction across every functional block, which explains the performance gap.

Clock behavior also differs. The L20 has a base clock of 1440 MHz and a boost of 2520 MHz. The RTX 4090 D starts at a much higher 2280 MHz base and matches the same 2520 MHz boost. The higher base clock on the RTX 4090 D suggests better sustained performance under load, whereas the L20 likely relies on boost behavior to reach its peak. Memory technology splits them further: the L20 uses GDDR6 at 18 Gbps effective, while the RTX 4090 D uses GDDR6X at 21 Gbps. Both run on a 384-bit bus, but the faster memory on the RTX 4090 D yields 1.01 TB/s of bandwidth versus 864.0 GB/s on the L20.

FAQ

Q: Which card has more memory?

A: The NVIDIA L20 has 48 GB of GDDR6, while the NVIDIA GeForce RTX 4090 D has 24 GB of GDDR6X.

Q: Is the RTX 4090 D faster in the shared benchmarks?

A: Yes. It wins Geekbench OpenCL with 278,621 against 274,276 (1.6% ahead) and Geekbench Vulkan with 246,941 against 228,018 (7.7% ahead).

Q: Do both cards use the same chip?

A: Yes, both are based on the AD102 chip with the Ada Lovelace architecture, built on TSMC’s 5 nm process with 76,300 million transistors.

Q: What is the power consumption difference?

A: The L20 has a TDP of 275 W and a suggested PSU of 600 W, while the RTX 4090 D has a TDP of 425 W and a suggested PSU of 800 W.

Q: Which card is better for a compact build?

A: The L20 is dual-slot and 267 mm long, while the RTX 4090 D is triple-slot and 304 mm long. The L20 also has a lower TDP, making it more flexible for space- and cooling-constrained systems.

Q: Are the RT cores and tensor cores the same count on both?

A: No. The L20 has 92 RT cores and 368 tensor cores, while the RTX 4090 D has 114 RT cores and 456 tensor cores.

Specification Differences

| Specification | NVIDIA L20 | NVIDIA GeForce RTX 4090 D |

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

| Generation | Server Ada (Lxx) | GeForce 40 |

| Base Clock | 1440 MHz | 2280 MHz |

| Memory Size | 48 GB | 24 GB |

| Memory Type | GDDR6 | GDDR6X |

| Memory Clock | 2250 MHz / 18 Gbps effective | 1313 MHz / 21 Gbps effective |

| Memory Bandwidth | 864.0 GB/s | 1.01 TB/s |

| Shading Units | 11776 | 14592 |

| TMUs | 368 | 456 |

| ROPs | 128 | 176 |

| RT Cores | 92 | 114 |

| Tensor Cores | 368 | 456 |

| Pixel Rate | 322.6 GPixel/s | 443.5 GPixel/s |

| Texture Rate | 927.4 GTexel/s | 1,149.1 GTexel/s |

| FP32 | 59.35 TFLOPS | 73.54 TFLOPS |

| FP16 | 59.35 TFLOPS (1:1) | 73.54 TFLOPS (1:1) |

| TDP | 275 W | 425 W |

| Slot Width | Dual-slot | Triple-slot |

| Suggested PSU | 600 W | 800 W |

| Display Outputs | 4x DisplayPort 1.4a | 1x HDMI 2.1, 3x DisplayPort 1.4a |

| Dimensions | 267 mm x 111 mm | 304 mm x 137 mm x 61 mm |

| Release Date | 2023-11-15 | 2023-12-27 |

| Production Status | Active | End-of-life |

| Launch MSRP | None | 1,599 USD |

Head-to-Head Benchmarks

The shared benchmark suite consists of only two tests, and the RTX 4090 D takes both. In Geekbench OpenCL, the RTX 4090 D scores 278,621, which is 1.6% higher than the L20’s 274,276. That is a close result, nearly within run-to-run variance, but the direction is consistent with the hardware configuration. The RTX 4090 D has 2,816 more shading units and a substantially higher base clock, which should translate into better compute throughput in OpenCL workloads that are not memory-bound.

Geekbench Vulkan tells a clearer story. The RTX 4090 D wins with 246,941 versus 228,018, a 7.7% margin. Vulkan often stresses graphics pipeline throughput, and the RTX 4090 D’s advantages in ROPs (176 vs 128), texture rate (1,149.1 GTexel/s vs 927.4 GTexel/s), and pixel rate (443.5 GPixel/s vs 322.6 GPixel/s) are directly relevant. The L20’s lower clock speeds and reduced resource counts hurt it more in this API, where parallelism and memory latency play a larger role.

Looking at the rivals, the L20’s average benchmark score of 251,147 puts it 11.6% ahead of the NVIDIA PG506-232 and 14.2% ahead of the AMD Radeon PRO W7900D. The RTX 4090 D’s average of 178,050 is 2.2% behind the NVIDIA RTX PRO 5000 Blackwell and 4.9% behind the NVIDIA A100 SXM4 40 GB. The L20’s percentile ranking of 99 versus 98 for the RTX 4090 D is notable — despite losing the head-to-head, the L20 sits in a higher tier relative to the entire GPU database, driven by its strong OpenCL showing and the weighting of professional workloads in that aggregate score.

The Verdict

The data supports a clear split. If you need maximum compute performance in a consumer context, the RTX 4090 D is the pick. It wins both shared benchmarks, has 73.54 TFLOPS of FP32 against 59.35 TFLOPS, and offers more RT cores, tensor cores, and texture units. Its 1.01 TB/s memory bandwidth is also 17% higher than the L20’s 864.0 GB/s. The RTX 4090 D is end-of-life, but its performance profile is straightforward: it is the faster card in the tests that matter for gaming and general compute.

The L20 is the choice for memory-bound professional work. Its 48 GB of GDDR6 is double the RTX 4090 D’s 24 GB, and it achieves that with a 275 W TDP and dual-slot design — far easier to fit into a server chassis or a dense workstation. The L20 also has more display outputs (4x DisplayPort 1.4a versus 1x HDMI and 3x DisplayPort), and it remains in active production. Its 99th percentile ranking and higher average benchmark score relative to its nearest rivals suggest that in the aggregate, it punches above its weight in the professional segment. For large models, high-resolution textures, or multi-GPU setups where power and space are at a premium, the L20’s capacity and efficiency make it the rational choice. For raw speed in the shared benchmarks, the RTX 4090 D wins — but the L20 wins the broader argument for deployment flexibility.