NVIDIA L20 vs NVIDIA Rubin GPU Comparison

FAQ

Q: What are the core architectural differences between the NVIDIA L20 and the NVIDIA Rubin GPU?

A: The L20 uses the AD102 chip on the Ada Lovelace architecture, built on a 5 nm process at TSMC with 76,300 million transistors on a 609 mm² die. The Rubin GPU uses the GR100 chip on the Rubin architecture, built on a 3 nm process at TSMC with 336,000 million transistors on a 1456 mm² die.

Q: How do the memory subsystems compare between these two GPUs?

A: The L20 has 48 GB of GDDR6 memory on a 384-bit bus, delivering 864.0 GB/s of bandwidth. The Rubin GPU has 288 GB of HBM4 memory on a 16384-bit bus, delivering 22.1 TB/s of bandwidth.

Q: What are the compute capabilities in terms of FP32 and FP16 throughput?

A: The L20 delivers 59.35 TFLOPS for both FP32 and FP16 (1:1 ratio). The Rubin GPU delivers 130.0 TFLOPS for FP32 and 260.0 TFLOPS for FP16 (2:1 ratio).

Q: What is the power requirement for each card?

A: The L20 has a TDP of 275 W and requires a 600 W suggested PSU, using a single 16-pin connector. The Rubin GPU has a TDP of 2300 W and requires a 2700 W suggested PSU.

Q: What form factors and display outputs do these GPUs use?

A: The L20 is a dual-slot card with 4x DisplayPort 1.4a outputs. The Rubin GPU is an SXM module with no display outputs.

Q: What are the benchmark scores for these GPUs?

A: The L20 has an average benchmark score of 251147, with a Geekbench OpenCL score of 274276 and a Geekbench Vulkan score of 228018. The Rubin GPU has no recorded benchmark scores and an average benchmark score of 0.

Where Each One Wins

The data shows a complete split: the L20 has recorded benchmark results, while the Rubin GPU has none. This means the L20 wins in all measured categories by default, as the Rubin GPU lacks any benchmark entries. The L20's average benchmark score of 251147 places it in the 99th percentile of all GPUs, while the Rubin GPU sits at the 50th percentile with a score of zero.

The L20's nearest rivals show its competitive position. It is 11.6% ahead of the NVIDIA PG506-232 (average score 225124) and 14.2% ahead of the AMD Radeon PRO W7900D (average score 219827). The L40 and RTX 6000 Ada Generation are ahead of the L20 by 11.6% and 12.6% respectively, with scores of 284111 and 287237. The Rubin GPU has no nearest rivals listed, confirming its lack of measured performance.

For use-case splits, the L20 is the only option with verified performance data. Its dual-slot form factor and DisplayPort outputs make it suitable for workstation tasks that require display connectivity. The Rubin GPU, as an SXM module with no outputs, is designed for server integration where display output is not needed.

Architecture Differences

The architecture gap between these two GPUs is substantial. The L20 uses the Ada Lovelace architecture with the AD102 chip, manufactured on a 5 nm process at TSMC. The Rubin GPU uses the Rubin architecture with the GR100 chip, manufactured on a 3 nm process at TSMC. The transistor count scales from 76,300 million on the L20 to 336,000 million on the Rubin GPU, a more than fourfold increase. Die size grows from 609 mm² to 1456 mm², and transistor density increases from 125.3M per mm² to 230.8M per mm².

The shading units differ significantly: the L20 has 11776, while the Rubin GPU has 28672. Texture mapping units increase from 368 on the L20 to 896 on the Rubin GPU. The L20 has 128 ROPs, while the Rubin GPU has only 24 ROPs. Ray tracing cores are present on the L20 (92), but the Rubin GPU has no recorded ray tracing core count. Tensor cores scale from 368 on the L20 to 896 on the Rubin GPU.

Memory architecture differs fundamentally. The L20 uses GDDR6 with a 384-bit bus, while the Rubin GPU uses HBM4 with a 16384-bit bus. Memory capacity jumps from 48 GB to 288 GB, and bandwidth increases from 864.0 GB/s to 22.1 TB/s. Clock speeds also differ: the L20 has a base clock of 1440 MHz and a boost clock of 2520 MHz, while the Rubin GPU has a base clock of 700 MHz and a boost clock of 2267 MHz. Effective memory speed is 18 Gbps on the L20 versus 10.8 Gbps on the Rubin GPU.

The L20 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The Rubin GPU has N/A for all API support. The L20 uses PCIe 4.0 x16, while the Rubin GPU uses PCIe 6.0 x16. The L20's production status is Active, released on 2023-11-15, and the Rubin GPU's production status is also Active, released on 2025-12-31. The L20's predecessor is Server Ampere and successor is Server Hopper. The Rubin GPU's predecessor is Server Blackwell, with no successor listed.

Specification Differences

The two GPUs differ in nearly every specification category. Process node: 5 nm for the L20 versus 3 nm for the Rubin GPU. Transistors: 76,300 million versus 336,000 million. Die size: 609 mm² versus 1456 mm². Transistor density: 125.3M per mm² versus 230.8M per mm².

Base clock: 1440 MHz versus 700 MHz. Boost clock: 2520 MHz versus 2267 MHz. Memory clock: 2250 MHz (18 Gbps effective) versus 2695 MHz (10.8 Gbps effective). Memory size: 48 GB versus 288 GB. Memory type: GDDR6 versus HBM4. Bus width: 384 bit versus 16384 bit. Bandwidth: 864.0 GB/s versus 22.1 TB/s.

Shading units: 11776 versus 28672. TMUs: 368 versus 896. ROPs: 128 versus 24. RT cores: 92 versus not recorded. Tensor cores: 368 versus 896. Pixel rate: 322.6 GPixel/s versus 54.41 GPixel/s. Texture rate: 927.4 GTexel/s versus 2,031.2 GTexel/s. FP32: 59.35 TFLOPS versus 130.0 TFLOPS. FP16: 59.35 TFLOPS (1:1) versus 260.0 TFLOPS (2:1).

TDP: 275 W versus 2300 W. Slot width: dual-slot versus SXM module. Power connectors: 1x 16-pin versus none recorded. Suggested PSU: 600 W versus 2700 W. Bus interface: PCIe 4.0 x16 versus PCIe 6.0 x16. Display outputs: 4x DisplayPort 1.4a versus no outputs. API support: DirectX 12 Ultimate, OpenGL 4.6, Vulkan 1.4 versus N/A for all.

Dimensions: the L20 is 267 mm (10.5 inches) long and 111 mm (4.4 inches) high. The Rubin GPU has no recorded dimensions. Release date: 2023-11-15 versus 2025-12-31.

Head-to-Head Benchmarks

There are no head-to-head benchmark entries in the database, and the Rubin GPU has no individual benchmark scores. The L20 has two recorded scores: a Geekbench OpenCL score of 274276 and a Geekbench Vulkan score of 228018. Its average benchmark score is 251147. The Rubin GPU's average benchmark score is 0, with no benchmark tests recorded.

The L20's performance percentile is 99, indicating it outperforms the vast majority of GPUs in the database. The Rubin GPU's percentile is 50, which reflects the absence of measured data rather than actual performance. The L20's nearest rivals demonstrate its standing: it is 11.6% ahead of the NVIDIA PG506-232 and 14.2% ahead of the AMD Radeon PRO W7900D. The NVIDIA L40 and RTX 6000 Ada Generation are 11.6% and 12.6% ahead of the L20, respectively.

Since the Rubin GPU has no benchmark data, any comparison between the two is limited to specifications. The Rubin GPU's FP32 throughput of 130.0 TFLOPS is more than double the L20's 59.35 TFLOPS. Its FP16 throughput of 260.0 TFLOPS is more than four times the L20's 59.35 TFLOPS. Memory bandwidth of 22.1 TB/s is over 25 times the L20's 864.0 GB/s. Texture rate of 2,031.2 GTexel/s is more than double the L20's 927.4 GTexel/s.

However, the L20 has a higher pixel rate of 322.6 GPixel/s compared to the Rubin GPU's 54.41 GPixel/s, a difference of roughly six times. The L20 also has more ROPs (128 versus 24). The Rubin GPU's lower base clock of 700 MHz versus 1440 MHz may contribute to this, though its boost clock of 2267 MHz is closer to the L20's 2520 MHz.

The Verdict

The data presents a clear situation: the NVIDIA L20 is the only GPU with verified benchmark performance, while the NVIDIA Rubin GPU has no recorded results. The L20's average benchmark score of 251147 and 99th percentile ranking confirm it as a high-performing card in the database. Its nearest rivals show it competes closely with the L40 and RTX 6000 Ada Generation, trailing them by 11.6% and 12.6% respectively, while staying ahead of the PG506-232 and Radeon PRO W7900D by 11.6% and 14.2%.

The Rubin GPU's specifications indicate a much larger hardware design, with substantially more transistors, memory, and compute throughput. Its FP32 performance of 130.0 TFLOPS and FP16 performance of 260.0 TFLOPS are far beyond the L20's capabilities. Memory capacity of 288 GB and bandwidth of 22.1 TB/s dwarf the L20's 48 GB and 864.0 GB/s. These specifications point to a server-oriented device, as indicated by the SXM module form factor and lack of display outputs.

For users who need a card with recorded performance, display outputs, and a dual-slot form factor, the L20 is the only choice with data. Its 4x DisplayPort 1.4a outputs and PCIe 4.0 x16 interface make it suitable for workstation environments. The L20's 275 W TDP and 600 W suggested PSU are far more manageable than the Rubin GPU's 2300 W TDP and 2700 W suggested PSU.

For users who require maximum memory capacity and compute throughput in a server context, the Rubin GPU's specifications are compelling. The 288 GB HBM4 memory and 22.1 TB/s bandwidth provide an enormous memory pool. The 896 tensor cores and 896 TMUs suggest strong AI and texture processing potential. The Rubin GPU's PCIe 6.0 x16 interface is two generations ahead of the L20's PCIe 4.0 x16.

The release dates also matter: the L20 shipped on 2023-11-15, while the Rubin GPU is dated 2025-12-31. The Rubin GPU's successor status is not recorded, while the L20 has a successor in Server Hopper. The Rubin GPU's predecessor is Server Blackwell, placing it in a newer generation.

The lack of benchmark data for the Rubin GPU means its actual performance cannot be verified from the database. Any purchasing decision involving the Rubin GPU relies entirely on its specification sheet. The L20, by contrast, has proven scores that place it in the top percentile of all GPUs.

The verdict from the data: the L20 is the verified performer with a 99th percentile ranking and concrete benchmark scores. The Rubin GPU is a specification-driven product with no measured results, offering dramatically larger hardware but unproven real-world performance. Users who need confirmed results should select the L20. Users who prioritize raw specifications and can wait for a future release date may consider the Rubin GPU, but its performance remains unknown in the database.