GPU Comparison

The NVIDIA L40 and NVIDIA A100 PCIe 80 GB represent two distinct approaches to server acceleration, separated by a generation of architecture and a fundamental shift in design priorities. The benchmark data places both in the 99th percentile of all GPUs, but their performance profiles diverge sharply, with the L40 delivering significantly higher raw compute throughput while the A100 counters with superior memory capacity and bandwidth. This analysis breaks down the measurable differences.

Head-to-Head Benchmarks

The only direct benchmark comparison available is Geekbench OpenCL, and the result is decisive. The NVIDIA L40 scores 330,926 points, while the NVIDIA A100 PCIe 80 GB scores 207,124 points. This represents a 59.8% advantage for the L40, a substantial margin that underscores the architectural leap between the two generations.

Looking at the L40's broader benchmark context, its average benchmark score of 284,111 places it within a competitive cluster of professional accelerators. It sits just 1.1% below the NVIDIA RTX 6000 Ada Generation (287,237) and 3.9% below the NVIDIA L40S (295,763). The L40's OpenCL score of 330,926 is notably higher than its average, suggesting it excels in compute-heavy workloads. The L40 also outperforms the AMD Instinct MI300X (317,994) by 10.7% in average score, and it holds a 13.1% lead over the NVIDIA L20 (251,147).

The A100's average benchmark score of 207,124 is its Geekbench OpenCL result, as no other benchmarks are listed. Within its competitive set, the A100 leads the NVIDIA RTX 6000D (195,964) by 5.7% and the NVIDIA Tesla V100S PCIe 32 GB (194,415) by 6.5%. However, it trails the AMD Radeon PRO W7900D (219,827) by 5.8% and the NVIDIA PG506-232 (225,124) by 8%. The A100's position is less dominant within its peer group, and it falls far behind the L40 in the head-to-head comparison.

The data shows a clear winner in raw compute: the L40's 59.8% lead in OpenCL is a substantial gap that would be difficult to overcome in any compute-oriented task. The A100's advantage lies elsewhere, primarily in memory specifications, which we will examine next.

Architecture Differences

The architectural divide between these two GPUs is fundamental. The L40 is built on the Ada Lovelace architecture using a 5 nm process at TSMC, while the A100 uses the older Ampere architecture on a 7 nm process, also at TSMC. This process shrink allows the L40 to pack 76,300 million transistors onto a 609 mm² die, resulting in a transistor density of 125.3 million per square millimeter. The A100, by contrast, has 54,200 million transistors spread across a much larger 826 mm² die, yielding a significantly lower density of just 65.6 million per square millimeter.

The L40's chip, the AD102, is a modern design built for high throughput. The A100's GA100 chip is larger physically but less dense, reflecting its older process node. This difference in density has direct implications for performance and efficiency.

Clock speeds tell a similar story. The L40 has a base clock of 735 MHz and a boost clock of 2490 MHz, while the A100 runs at a base of 1065 MHz and a boost of 1410 MHz. The L40's higher boost clock, combined with its superior architecture, drives its massive compute advantage. The L40's memory clock is 2250 MHz (18 Gbps effective), while the A100's memory clock is 1512 MHz (3 Gbps effective).

The L40 also includes dedicated ray tracing cores, with 142 RT cores, while the A100 lists no RT cores at all. This is a feature difference that matters for rendering and visualization workloads. Both GPUs have tensor cores, with the L40 featuring 568 and the A100 featuring 432, but the L40's are from a newer generation.

Where Each One Wins

The data points to a clear split: the L40 wins on compute performance and features, while the A100 wins on memory capacity and bandwidth.

The L40's 59.8% lead in OpenCL performance makes it the clear choice for any workload that relies on raw compute throughput. Its FP32 performance of 90.52 TFLOPS dwarfs the A100's 19.49 TFLOPS, a nearly five-fold difference. The L40 also offers FP16 performance at 90.52 TFLOPS with a 1:1 ratio, while the A100 provides 77.97 TFLOPS at a 4:1 ratio. The L40's pixel rate of 478.1 GPixel/s and texture rate of 1,414.3 GTexel/s are more than double the A100's 225.6 GPixel/s and 609.1 GTexel/s, respectively. The L40 also has significantly more shading units (18,176 vs 6,912), TMUs (568 vs 432), and ROPs (192 vs 160).

For rendering, visualization, and general compute tasks, the L40 is the superior card. Its higher clock speeds, more shading units, and RT core support make it a more versatile and faster accelerator. The L40 also has display outputs (4x DisplayPort 1.4a), while the A100 has none, making the L40 suitable for workstation use with direct display connectivity.

The A100 wins on memory. It offers 80 GB of HBM2e memory compared to the L40's 48 GB of GDDR6. The A100's memory bus is 5120-bit, versus the L40's 384-bit, and its bandwidth is 1.94 TB/s compared to the L40's 864.0 GB/s. For workloads that require massive memory capacity or extremely high bandwidth, such as large language model inference or certain scientific simulations, the A100's memory advantage is significant. The A100's larger memory pool allows it to hold larger datasets and models in memory, potentially avoiding costly transfers.

Specification Differences

The two cards share several specifications, including a 300 W TDP, dual-slot width, 700 W suggested PSU, PCIe 4.0 x16 interface, and identical dimensions (267 mm length, 111 mm height). Both are end-of-life products. The power connectors differ: the L40 uses a 1x 16-pin connector, while the A100 uses an 8-pin EPS.

Key differences are summarized below:

• Architecture: Ada Lovelace (L40) vs Ampere (A100)
• Process Node: 5 nm (L40) vs 7 nm (A100)
• Transistors: 76,300 million (L40) vs 54,200 million (A100)
• Die Size: 609 mm² (L40) vs 826 mm² (A100)
• Transistor Density: 125.3M / mm² (L40) vs 65.6M / mm² (A100)
• Base Clock: 735 MHz (L40) vs 1065 MHz (A100)
• Boost Clock: 2490 MHz (L40) vs 1410 MHz (A100)
• Memory Size: 48 GB GDDR6 (L40) vs 80 GB HBM2e (A100)
• Memory Bus Width: 384 bit (L40) vs 5120 bit (A100)
• Memory Bandwidth: 864.0 GB/s (L40) vs 1.94 TB/s (A100)
• Shading Units: 18,176 (L40) vs 6,912 (A100)
• TMUs: 568 (L40) vs 432 (A100)
• ROPs: 192 (L40) vs 160 (A100)
• RT Cores: 142 (L40) vs None (A100)
• Tensor Cores: 568 (L40) vs 432 (A100)
• FP32 Performance: 90.52 TFLOPS (L40) vs 19.49 TFLOPS (A100)
• FP16 Performance: 90.52 TFLOPS (1:1) (L40) vs 77.97 TFLOPS (4:1) (A100)
• Pixel Rate: 478.1 GPixel/s (L40) vs 225.6 GPixel/s (A100)
• Texture Rate: 1,414.3 GTexel/s (L40) vs 609.1 GTexel/s (A100)
• Display Outputs: 4x DisplayPort 1.4a (L40) vs No outputs (A100)
• API Support: DirectX 12 Ultimate, OpenGL 4.6, Vulkan 1.4 (L40) vs None listed (A100)
• Release Date: 2022-10-12 (L40) vs 2021-06-27 (A100)
• Predecessor: Server Ampere (L40) vs Tesla Turing (A100)
• Successor: Server Hopper (L40) vs Server Ada (A100)

FAQ

Q: Which GPU is faster in the Geekbench OpenCL benchmark?

A: The NVIDIA L40 scores 330,926, which is 59.8% higher than the NVIDIA A100 PCIe 80 GB's score of 207,124.

Q: How do the memory capacities compare?

A: The A100 has 80 GB of HBM2e memory, whereas the L40 has 48 GB of GDDR6 memory. The A100 also has a wider 5120-bit memory bus and higher bandwidth at 1.94 TB/s, compared to the L40's 384-bit bus and 864.0 GB/s.

Q: Does the L40 support ray tracing?

A: Yes, the L40 has 142 dedicated RT cores. The A100 lists no RT cores.

Q: What is the difference in FP32 compute performance?

A: The L40 delivers 90.52 TFLOPS of FP32 performance, while the A100 provides 19.49 TFLOPS.

Q: Are these GPUs still in production?

A: No, both the NVIDIA L40 and the NVIDIA A100 PCIe 80 GB are listed as end-of-life products.

Q: Do both cards have the same power consumption?

A: Yes, both have a 300 W TDP and a suggested PSU of 700 W. They are both dual-slot cards with PCIe 4.0 x16 interfaces.