AMD Instinct MI100 vs NVIDIA L20 Comparison

NVIDIA L20 and AMD Instinct MI100 are both dual-slot server accelerators, but they target very different moments in the AI and compute lifecycle. The L20 is an active Ada Lovelace part with a 99th-percentile standing, while the MI100 is an end-of-life CDNA 1.0 card that still holds a 96th-percentile rank. In the single available head-to-head benchmark, the L20 dominates, but the MI100’s specialized memory subsystem and unique architecture make it a distinct entity rather than a direct failure.

Head-to-Head Benchmarks

The only shared benchmark result in the database is Geekbench OpenCL, and the NVIDIA L20 wins decisively. The L20 scores 274,276 points against the MI100’s 139,035, a delta of 97.3%. That is nearly double the raw compute output in a synthetic workload that stresses general-purpose GPU compute. In practical terms, the L20’s score places it 11.6% ahead of the NVIDIA PG506-232 and 14.2% ahead of the AMD Radeon PRO W7900D, while sitting 11.6% behind the NVIDIA L40 and 12.6% behind the RTX 6000 Ada Generation. The MI100, by contrast, sits in a much tighter competitive cluster: it is 0.7% ahead of the Tesla V100 PCIe 16 GB, 0.9% ahead of the Tesla V100 SXM2 32 GB, 1.9% ahead of the AMD Radeon PRO V620, and 2.4% ahead of the AMD Radeon Pro W6800X Duo. That delta of 97.3% between the two cards is not incremental; it is a generational leap in raw OpenCL throughput.

The L20 also holds a second benchmark entry—Geekbench Vulkan at 228,018—which the MI100 lacks entirely, as the AMD card reports no Vulkan API support. This absence is telling: the MI100 is built for a compute-only role with no graphics or rasterization path, whereas the L20 is a full-featured GPU with DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4 support. The L20’s average benchmark score across all tests is 251,147, derived from its two entries, while the MI100’s average is 139,035 from a single test. The percentile rankings confirm the separation: the L20 sits in the 99th percentile of all GPUs, while the MI100 sits in the 96th. That three-percentile gap in the database’s distribution means the L20 is not just faster in one test; it is categorically higher in overall standing.

Architecture Differences

The architectural chasm between these two cards is wide. The NVIDIA L20 uses the AD102 chip on a 5 nm TSMC process, packing 76,300 million transistors onto a 609 mm² die. The AMD Instinct MI100 uses the Arcturus chip on a 7 nm TSMC process, with 25,600 million transistors on a larger 750 mm² die. The transistor density tells the story: the L20 achieves 125.3M transistors per mm², while the MI100 manages only 34.1M per mm². That is a 3.7x density advantage for the L20, enabled by the newer node. The MI100’s larger die but far fewer transistors means it is a sparser, older design.

The memory subsystems are radically different. The L20 has 48 GB of GDDR6 on a 384-bit bus, yielding 864.0 GB/s of bandwidth. The MI100 counters with 32 GB of HBM2 on a 4096-bit bus, delivering 1.23 TB/s—a 42.4% bandwidth advantage for the AMD part despite having one-third less capacity. This is a deliberate trade-off: the MI100 prioritizes memory throughput for HPC workloads, while the L20 balances capacity and bandwidth for AI inference and training. The L20’s memory clock is 2250 MHz (18 Gbps effective), while the MI100’s is 1200 MHz (2.4 Gbps effective). The L20’s higher clock speed is offset by the MI100’s massive bus width.

Compute resources follow a similar pattern of divergence. The L20 has 11,776 shading units, 368 TMUs, 128 ROPs, 92 RT cores, and 368 tensor cores. The MI100 has 7,680 shading units, 480 TMUs, and 64 ROPs—with no RT cores and no tensor cores listed. The L20’s FP32 throughput is 59.35 TFLOPS, while the MI100’s is 23.07 TFLOPS. In FP16, the L20 matches its FP32 rate at 59.35 TFLOPS (1:1), while the MI100 doubles its FP32 rate to 46.14 TFLOPS (2:1). The MI100’s FP16 advantage ratio suggests it was designed for mixed-precision workloads, but the L20’s absolute FP16 number is still 28.6% higher. Pixel rate and texture rate also favor the L20: 322.6 GPixel/s vs 96.13 GPixel/s, and 927.4 GTexel/s vs 721.0 GTexel/s.

Clock speeds differ as well. The L20 runs at a base of 1440 MHz and boosts to 2520 MHz. The MI100 runs at 1000 MHz base and 1502 MHz boost. The L20’s boost clock is 67.8% higher than the MI100’s, which explains much of its compute advantage despite the MI100’s wider memory bus. Power draw is close: the L20 is rated at 275 W with a 1x 16-pin connector and a 600 W suggested PSU, while the MI100 is rated at 300 W with 2x 8-pin connectors and a 700 W suggested PSU. Both are dual-slot cards with identical physical dimensions: 267 mm (10.5 inches) long and 111 mm (4.4 inches) high.

FAQ

Q: Which card has higher memory bandwidth?

A: The AMD Instinct MI100 has 1.23 TB/s of bandwidth from its 4096-bit HBM2 interface, which is 42.4% higher than the NVIDIA L20’s 864.0 GB/s from a 384-bit GDDR6 bus.

Q: Does the MI100 support any graphics APIs?

A: No. The MI100 reports N/A for DirectX, OpenGL, and Vulkan, and has no display outputs. The L20, by contrast, supports DirectX 12 Ultimate, OpenGL 4.6, Vulkan 1.4, and has four DisplayPort 1.4a outputs.

Q: Why is the L20’s FP32 score so much higher than the MI100’s?

A: The L20 delivers 59.35 TFLOPS FP32 versus 23.07 TFLOPS for the MI100. This is driven by the L20’s 11,776 shading units and 2520 MHz boost clock, compared to the MI100’s 7,680 shading units and 1502 MHz boost clock.

Q: Which card is better for FP16 workloads?

A: In absolute terms, the L20 wins with 59.35 TFLOPS FP16 (1:1 ratio), while the MI100 offers 46.14 TFLOPS FP16 (2:1 ratio). However, the MI100’s 2:1 ratio means it doubles its FP32 rate, whereas the L20 does not.

Q: What is the production status of each card?

A: The NVIDIA L20 is listed as Active, released on 2023-11-15. The AMD Instinct MI100 is End-of-life, released on 2020-11-15.

Q: How does the L20 compare to its nearest rivals?

A: The L20 is 11.6% faster than the NVIDIA PG506-232 and 14.2% faster than the AMD Radeon PRO W7900D, but it trails the NVIDIA L40 by 11.6% and the RTX 6000 Ada Generation by 12.6%.

The Verdict

The data points to a clear winner for general compute and AI workloads: the NVIDIA L20. Its 97.3% lead in the only shared benchmark is overwhelming, and its 99th-percentile standing versus the MI100’s 96th percentile confirms the hierarchy. The L20’s 59.35 TFLOPS FP32 and FP16 performance, combined with 48 GB of memory, makes it a more versatile and faster accelerator for any task that leverages standard compute paths. Its support for DirectX, Vulkan, and OpenGL also means it can handle graphics-adjacent workloads, which the MI100 cannot.

However, the MI100 is not without merit for specific use cases. Its 1.23 TB/s memory bandwidth is a genuine advantage—42.4% higher than the L20—which could matter for memory-bound HPC kernels that saturate bandwidth rather than compute. Its 32 GB of HBM2 is also faster per byte than GDDR6, and the 4096-bit bus is a legacy design that still delivers top-tier throughput. For workloads that are purely memory-latency or bandwidth sensitive and do not require modern APIs or tensor cores, the MI100 remains a viable, if end-of-life, option.

The verdict is straightforward: choose the NVIDIA L20 for nearly everything—higher compute, more memory, active production status, and a broader feature set. Choose the AMD Instinct MI100 only if your specific workload is memory-bandwidth-bound and you can live with its lack of graphics support, lower FP32, and end-of-life status. The L20 is the modern choice; the MI100 is a specialized relic with one standout trait.

Specification Differences

| Specification | NVIDIA L20 | AMD Instinct MI100 |

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

| Architecture | Ada Lovelace | CDNA 1.0 |

| Process Node | 5 nm | 7 nm |

| Transistors | 76,300 million | 25,600 million |

| Die Size | 609 mm² | 750 mm² |

| Transistor Density | 125.3M / mm² | 34.1M / mm² |

| Base Clock | 1440 MHz | 1000 MHz |

| Boost Clock | 2520 MHz | 1502 MHz |

| Memory Size | 48 GB | 32 GB |

| Memory Type | GDDR6 | HBM2 |

| Memory Bus Width | 384 bit | 4096 bit |

| Memory Bandwidth | 864.0 GB/s | 1.23 TB/s |

| Shading Units | 11776 | 7680 |

| TMUs | 368 | 480 |

| ROPs | 128 | 64 |

| RT Cores | 92 | N/A |

| Tensor Cores | 368 | N/A |

| Pixel Rate | 322.6 GPixel/s | 96.13 GPixel/s |

| Texture Rate | 927.4 GTexel/s | 721.0 GTexel/s |

| FP32 | 59.35 TFLOPS | 23.07 TFLOPS |

| FP16 | 59.35 TFLOPS (1:1) | 46.14 TFLOPS (2:1) |

| TDP | 275 W | 300 W |

| Power Connectors | 1x 16-pin | 2x 8-pin |

| Suggested PSU | 600 W | 700 W |

| Display Outputs | 4x DisplayPort 1.4a | No outputs |

| DirectX | 12 Ultimate (12_2) | N/A |

| OpenGL | 4.6 | N/A |

| Vulkan | 1.4 | N/A |

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

| Release Date | 2023-11-15 | 2020-11-15 |