AMD Instinct MI308X vs NVIDIA L20 Comparison

Where Each One Wins

The AMD Instinct MI308X and NVIDIA L20 serve fundamentally different roles in the accelerator landscape, and the recorded data makes that split clear. The MI308X is a compute-oriented OAM module with no display outputs, a 192 GB HBM3 memory pool, and a 8192-bit memory bus, all of which point toward large-scale compute workloads where memory capacity and bandwidth dominate. The L20, by contrast, is a dual-slot PCIe card with 4x DisplayPort 1.4a outputs, 48 GB of GDDR6 memory, and a 384-bit bus, positioning it as a more conventional server GPU with both compute and display capability.

The benchmark data shows no head-to-head results between these two parts, but the L20 has recorded scores in the database: a Geekbench OpenCL score of 274276 and a Geekbench Vulkan score of 228018, with an average benchmark score of 251147. That average places the L20 in the 99th percentile of all GPUs in the database, a very strong position. The MI308X, in contrast, has no recorded benchmark scores and sits at the 50th percentile, reflecting the absence of measured data rather than actual performance characteristics.

The MI308X wins on memory capacity, memory bandwidth, raw FP32 throughput, texture rate, and transistor count. It delivers 192 GB of memory versus 48 GB, 5.32 TB/s of bandwidth versus 864.0 GB/s, 81.72 TFLOPS of FP32 versus 59.35 TFLOPS, and 2,553.6 GTexel/s versus 927.4 GTexel/s. The L20 wins on clock speeds, pixel rate, power efficiency as expressed by TDP, API support, display outputs, and the availability of measured benchmark scores. Its boost clock reaches 2520 MHz versus 2100 MHz, its pixel rate is 322.6 GPixel/s versus 0 MPixel/s, and its TDP is 275 W versus 750 W.

The use-case split is therefore straightforward. The MI308X is built for memory-bound compute tasks where the 192 GB pool and 5.32 TB/s bandwidth are decisive. The L20 is built for general server duties that benefit from a standard PCIe form factor, lower power draw, and display outputs, while still delivering strong compute throughput.

Architecture Differences

The two accelerators come from different architectural families and different design philosophies. The MI308X uses the Aqua Vanjaram chip built on CDNA 3.0, AMD's compute-focused architecture, fabricated by TSMC on a 5 nm process. The chip contains 153,000 million transistors on a 1017 mm² die, yielding a transistor density of 150.4M per mm². The L20 uses the AD102 chip built on Ada Lovelace, NVIDIA's server and workstation architecture, also fabricated by TSMC on a 5 nm process. The AD102 contains 76,300 million transistors on a 609 mm² die, yielding a density of 125.3M per mm².

The MI308X has 19,456 shading units, 1,216 texture mapping units, and no ROPs, no ray tracing cores, and no tensor cores listed. Its pixel rate is recorded as 0 MPixel/s, which is consistent with a compute accelerator that has no display or raster pipeline. The L20 has 11,776 shading units, 368 TMUs, 128 ROPs, 92 ray tracing cores, and 368 tensor cores. Its pixel rate is 322.6 GPixel/s, and its texture rate is 927.4 GTexel/s.

Memory architecture differs sharply. The MI308X uses HBM3 with a 8192-bit bus and 5.32 TB/s bandwidth, while the L20 uses GDDR6 with a 384-bit bus and 864.0 GB/s bandwidth. The MI308X has 192 GB of memory, four times the L20's 48 GB. The memory clocks also differ: the MI308X runs at 1300 MHz with 5.2 Gbps effective, while the L20 runs at 2250 MHz with 18 Gbps effective.

The base clocks differ as well. The MI308X has a base clock of 1000 MHz and a boost clock of 2100 MHz. The L20 has a base clock of 1440 MHz and a boost clock of 2520 MHz. The L20's higher clocks are typical of a smaller, more lightly configured chip, while the MI308X relies on massive parallelism and memory bandwidth.

API support is another clear divide. The MI308X lists N/A for DirectX, OpenGL, and Vulkan, reflecting its non-rendering compute focus. The L20 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The L20 also has display outputs (4x DisplayPort 1.4a), while the MI308X has none.

The bus interfaces differ: the MI308X uses PCIe 5.0 x16, while the L20 uses PCIe 4.0 x16. The slot formats differ as well: the MI308X is an OAM module with no power connectors listed, while the L20 is a dual-slot card with a single 16-pin power connector. The suggested PSU for the MI308X is 1150 W, while the L20 suggests 600 W. The L20 has physical dimensions of 267 mm length and 111 mm height; the MI308X has no dimensions recorded.

Head-to-Head Benchmarks

The database contains no direct head-to-head benchmark results between the MI308X and the L20. The head-to-head array is empty, and the win counts are zero for both parts. However, the recorded benchmark data for the L20 and the specification-level comparisons provide the basis for analysis.

The L20's Geekbench OpenCL score of 274276 and Geekbench Vulkan score of 228018 give it an average benchmark score of 251147. That average places it in the 99th percentile of all GPUs. The nearest rivals in the database confirm the L20's standing. It leads the NVIDIA PG506-232 by 11.6 percent, with the PG506-232 averaging 225124. It leads the AMD Radeon PRO W7900D by 14.2 percent, with that card averaging 219827. It trails the NVIDIA L40 by 11.6 percent, with the L40 averaging 284111, and trails the NVIDIA RTX 6000 Ada Generation by 12.6 percent, with that card averaging 287237.

The MI308X has no benchmark scores in the database, so its percentile of 50 reflects missing data rather than measured performance. The specification data, however, indicates where its advantages lie. In FP32 throughput, the MI308X delivers 81.72 TFLOPS versus the L20's 59.35 TFLOPS, a lead of roughly 37.7 percent. In texture rate, the MI308X delivers 2,553.6 GTexel/s versus 927.4 GTexel/s, a lead of roughly 175 percent. In memory bandwidth, the MI308X delivers 5.32 TB/s versus 864.0 GB/s, a lead of roughly 516 percent. In memory capacity, the MI308X offers 192 GB versus 48 GB, four times the capacity.

The L20 counters in pixel rate, delivering 322.6 GPixel/s versus 0 MPixel/s for the MI308X, and in clock speeds, with a boost of 2520 MHz versus 2100 MHz. The L20 also has a lower TDP of 275 W versus 750 W, and a lower suggested PSU of 600 W versus 1150 W.

The FP32 comparison is worth examining closely. The MI308X's 81.72 TFLOPS figure is recorded as FP32 and also as FP16 at a 1:1 ratio, meaning both formats run at the same rate. The L20's 59.35 TFLOPS is likewise recorded as FP32 and FP16 at 1:1. The MI308X therefore leads in both formats by the same margin.

The memory bandwidth comparison is the largest single gap in the data. A 5.32 TB/s memory subsystem versus 864.0 GB/s represents a difference of more than five times, and the bus width difference of 8192 bits versus 384 bits is the structural cause. The MI308X's HBM3 memory operates at a lower effective data rate of 5.2 Gbps versus the L20's 18 Gbps, but the enormous bus width more than compensates.

The Verdict

The data supports a clear division of roles. The AMD Instinct MI308X is the choice for workloads that require massive memory capacity and bandwidth. Its 192 GB of HBM3 memory, 5.32 TB/s bandwidth, and 81.72 TFLOPS of FP32 throughput place it in a different performance class for memory-bound compute tasks. The absence of display outputs, raster pipeline, and API support confirms that it is not intended for graphics or general-purpose rendering.

The NVIDIA L20 is the choice for server workloads that need a conventional PCIe card with display outputs, broad API support, and moderate power consumption. Its 48 GB of GDDR6 memory, 864.0 GB/s bandwidth, and 59.35 TFLOPS of FP32 throughput are lower than the MI308X on paper, but its measured benchmark results show strong real-world performance. The L20's average benchmark score of 251147 places it in the 99th percentile, and it leads the PG506-232 by 11.6 percent and the Radeon PRO W7900D by 14.2 percent in the database's nearest rival comparisons.

The power and form factor differences reinforce the split. The MI308X is an OAM module with a 750 W TDP and a suggested PSU of 1150 W, which requires specialized server infrastructure. The L20 is a dual-slot card with a 275 W TDP and a suggested PSU of 600 W, which fits more conventional server configurations. The L20 also has a PCIe 4.0 x16 interface and a 16-pin power connector, while the MI308X uses PCIe 5.0 x16 and has no power connectors listed.

Neither part is a substitute for the other. The MI308X targets a narrow but demanding segment of compute acceleration, while the L20 targets a broader range of server tasks including those that involve display output and API-level rendering. The absence of MI308X benchmark scores in the database means its measured performance cannot be compared directly to the L20's recorded results, but the specification data indicates that the MI308X holds decisive advantages in memory capacity, memory bandwidth, and raw compute throughput.

FAQ

Q: Which accelerator has more memory?

A: The AMD Instinct MI308X has 192 GB of HBM3 memory, while the NVIDIA L20 has 48 GB of GDDR6 memory. The MI308X offers four times the capacity.

Q: How does memory bandwidth compare between the two?

A: The MI308X delivers 5.32 TB/s over an 8192-bit bus, while the L20 delivers 864.0 GB/s over a 384-bit bus. The MI308X has more than five times the bandwidth.

Q: What are the FP32 performance figures?

A: The MI308X delivers 81.72 TFLOPS of FP32, and the L20 delivers 59.35 TFLOPS. Both parts run FP16 at a 1:1 ratio, so the same figures apply to FP16.

Q: Does the L20 have measured benchmark scores?

A: Yes. The L20 has a Geekbench OpenCL score of 274276, a Geekbench Vulkan score of 228018, and an average benchmark score of 251147, placing it in the 99th percentile of all GPUs in the database.

Q: Does the MI308X have any benchmark scores in the database?

A: No. The MI308X has no recorded benchmarks, and its 50th percentile reflects the absence of measured data rather than actual performance.

Q: Which accelerator has display outputs?

A: The NVIDIA L20 has 4x DisplayPort 1.4a outputs. The AMD Instinct MI308X has no display outputs, consistent with its compute-only design.

Q: How do the nearest rivals compare to the L20?

A: The L20 leads the NVIDIA PG506-232 by 11.6 percent and the AMD Radeon PRO W7900D by 14.2 percent. It trails the NVIDIA L40 by 11.6 percent and the NVIDIA RTX 6000 Ada Generation by 12.6 percent.

Specification Differences

| Specification | AMD Instinct MI308X | NVIDIA L20 |

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

| Chip | Aqua Vanjaram | AD102 |

| Architecture | CDNA 3.0 | Ada Lovelace |

| Process node | 5 nm | 5 nm |

| Transistors | 153,000 million | 76,300 million |

| Die size | 1017 mm² | 609 mm² |

| Transistor density | 150.4M / mm² | 125.3M / mm² |

| Base clock | 1000 MHz | 1440 MHz |

| Boost clock | 2100 MHz | 2520 MHz |

| Memory size | 192 GB | 48 GB |

| Memory type | HBM3 | GDDR6 |

| Memory bus width | 8192 bit | 384 bit |

| Memory bandwidth | 5.32 TB/s | 864.0 GB/s |

| Memory clock | 1300 MHz, 5.2 Gbps effective | 2250 MHz, 18 Gbps effective |

| Shading units | 19456 | 11776 |

| TMUs | 1216 | 368 |

| ROPs | 0 | 128 |

| Ray tracing cores | None listed | 92 |

| Tensor cores | None listed | 368 |

| Pixel rate | 0 MPixel/s | 322.6 GPixel/s |

| Texture rate | 2,553.6 GTexel/s | 927.4 GTexel/s |

| FP32 | 81.72 TFLOPS | 59.35 TFLOPS |

| FP16 | 81.72 TFLOPS (1:1) | 59.35 TFLOPS (1:1) |

| TDP | 750 W | 275 W |

| Slot width | OAM Module | Dual-slot |

| Power connectors | None | 1x 16-pin |

| Suggested PSU | 1150 W | 600 W |

| Bus interface | PCIe 5.0 x16 | PCIe 4.0 x16 |

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

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

| OpenGL | N/A | 4.6 |

| Vulkan | N/A | 1.4 |

| Dimensions | Not recorded | 267 mm length, 111 mm height |

| Release date | 2023-12-05 | 2023-11-15 |

| Predecessor | Radeon Instinct | Server Ampere |

| Successor | None listed | Server Hopper |

| Production status | Not recorded | Active |