NVIDIA H20 vs NVIDIA H800 SXM5 Comparison

The Verdict

The NVIDIA H20 and NVIDIA H800 SXM5 are both Hopper-generation server accelerators built on the GH100 chip, but the recorded data positions them for distinctly different workloads. The H800 SXM5 delivers substantially higher raw compute throughput, with FP32 performance of 59.30 TFLOPS versus the H20's 39.54 TFLOPS, and FP16 performance of 237.2 TFLOPS (4:1) versus the H20's 79.07 TFLOPS (2:1). The H20 counters with a larger memory pool of 96 GB compared to 80 GB, and higher memory bandwidth at 4.03 TB/s versus 3.36 TB/s. The H800 SXM5 also holds an advantage in shading units (16896 versus 9984), texture mapping units (528 versus 312), and tensor cores (528 versus 312). The H20's higher boost clock of 1980 MHz versus 1755 MHz partially compensates, but the H800 SXM5's wider execution resources dominate in peak throughput metrics. Both cards sit at the 50th percentile against all GPUs in the database, and neither has recorded benchmark scores or nearest rivals, so the analysis relies on architectural specifications rather than measured performance deltas.

The data indicates that systems requiring maximum FP32 or FP16 compute should select the H800 SXM5. The H20's advantage lies in memory capacity and bandwidth, making it suitable for workloads that stress memory residency rather than raw arithmetic throughput. The H800 SXM5 demands a higher power envelope at 700 W versus 500 W, and a suggested PSU of 1100 W versus 900 W, which factors into platform planning. Both use PCIe 5.0 x16 interfaces and SXM modules with no display outputs. The production status for both is Active, with the H800 SXM5 released on 2023-03-20 and the H20 on 2024-01-31. Neither has a launch MSRP recorded in the database.

Where Each One Wins

The H800 SXM5 wins decisively in compute-bound scenarios. Its FP32 output of 59.30 TFLOPS exceeds the H20's 39.54 TFLOPS by roughly 50%. In FP16 work, the gap widens dramatically: the H800 SXM5 delivers 237.2 TFLOPS (4:1) against the H20's 79.07 TFLOPS (2:1), a threefold advantage. The H800 SXM5 also doubles the texture rate at 926.6 GTexel/s versus 617.8 GTexel/s, and its pixel rate of 42.12 GPixel/s compares to 47.52 GPixel/s for the H20. The H800 SXM5's higher shading unit count (16896 versus 9984) and tensor core count (528 versus 312) reinforce its position for dense matrix operations and general GPU compute.

The H20 wins in memory-bound scenarios. Its 96 GB HBM3 capacity provides 20% more memory than the H800 SXM5's 80 GB. Memory bandwidth follows suit: 4.03 TB/s versus 3.36 TB/s, a 20% advantage for the H20. The H20 also runs a wider 6144-bit memory bus compared to 5120-bit on the H800 SXM5, though both use the same 1313 MHz memory clock with 5.3 Gbps effective data rate. For workloads that fit within 80 GB, the H800 SXM5's compute lead likely prevails, but datasets exceeding 80 GB force a choice that favors the H20's larger pool. The H20's higher base clock (1830 MHz versus 1095 MHz) and boost clock (1980 MHz versus 1755 MHz) suggest better per-clock efficiency, but the H800 SXM5 compensates with more execution units.

Architecture Differences

Both cards derive from the GH100 chip on TSMC's 5 nm process, with identical transistor counts of 80,000 million and die sizes of 814 mm². The transistor density computes to 98.3M per mm² for both. The architecture is Hopper for each, with the generation listed as Server Hopper (Hxx). The H800 SXM5 ships with 16896 shading units, 528 TMUs, 528 tensor cores, and 24 ROPs. The H20 reduces these counts to 9984 shading units, 312 TMUs, 312 tensor cores, and the same 24 ROPs. This configuration suggests the H20 uses a partially disabled GH100 die, trading execution resources for higher clock speeds and memory capacity.

Clock behavior differs notably. The H20 runs a base clock of 1830 MHz and boosts to 1980 MHz. The H800 SXM5 runs a much lower base of 1095 MHz but boosts to 1755 MHz. The H20's clocks are higher across the board, yet its FP32 throughput remains lower due to fewer active units. The FP16 ratio also differs: the H20 lists FP16 at 79.07 TFLOPS with a 2:1 ratio relative to FP32, while the H800 SXM5 lists 237.2 TFLOPS with a 4:1 ratio. This implies the H800 SXM5's tensor cores or FP16 paths are configured for higher throughput per clock, or the H20's FP16 path is more conservatively rated. Memory configuration diverges as well: the H20 uses a 6144-bit bus with 96 GB, while the H800 SXM5 uses a 5120-bit bus with 80 GB. Both employ HBM3 with the same effective memory speed of 5.3 Gbps, so the bandwidth difference stems purely from bus width.

The power delivery differs substantially. The H20 draws 500 W with a suggested PSU of 900 W. The H800 SXM5 draws 700 W with a suggested PSU of 1100 W, and it includes an 8-pin EPS power connector in the record, while the H20 lists no power connector detail. Both are SXM modules, both use PCIe 5.0 x16, and both have no display outputs. The API support is marked N/A for the H20 across DirectX, OpenGL, and Vulkan, while the H800 SXM5 lists null values for those fields, indicating neither targets graphics workloads. The H800 SXM5 released earlier on 2023-03-20, with the H20 following on 2024-01-31. Both list Server Ada as predecessor and Server Blackwell as successor.

FAQ

Q: Which card has higher FP32 compute performance?

A: The H800 SXM5 delivers 59.30 TFLOPS FP32, while the H20 provides 39.54 TFLOPS. The H800 SXM5 leads by roughly 50% in this metric.

Q: How do the memory capacities compare?

A: The H20 has 96 GB HBM3, while the H800 SXM5 has 80 GB HBM3. The H20 offers 20% more memory capacity and also provides higher bandwidth at 4.03 TB/s versus 3.36 TB/s.

Q: Are both cards based on the same chip?

A: Yes, both use the GH100 chip on TSMC 5 nm with 80,000 million transistors and an 814 mm² die size. The architecture is Hopper for both.

Q: What is the power consumption difference?

A: The H20 has a 500 W TDP with a 900 W suggested PSU, while the H800 SXM5 has a 700 W TDP with a 1100 W suggested PSU.

Q: Which card has more tensor cores?

A: The H800 SXM5 has 528 tensor cores, while the H20 has 312 tensor cores. The H800 SXM5 also has more shading units (16896 versus 9984) and TMUs (528 versus 312).

Q: Do these cards support graphics APIs?

A: The H20 lists DirectX, OpenGL, and Vulkan as N/A, and the H800 SXM5 lists null values for those fields. Both are compute-focused accelerators with no display outputs.

Head-to-Head Benchmarks

No head-to-head benchmark results are recorded in the database for these two cards. The headToHeadBenchmarks array is empty, and both cards show zero benchmark scores with an average benchmark score of 0. The percentileVsAllGpus field places both at 50, indicating a neutral position against all GPUs in the database. Without measured performance deltas, the comparison must rely on specification-level analysis.

The largest compute gap appears in FP16 throughput. The H800 SXM5 records 237.2 TFLOPS (4:1), which is triple the H20's 79.07 TFLOPS (2:1). This difference suggests the H800 SXM5 is better suited for mixed-precision training or inference where FP16 dominates. The FP32 gap is smaller but still significant: 59.30 TFLOPS versus 39.54 TFLOPS, a 50% advantage for the H800 SXM5. Texture rate follows a similar pattern, with the H800 SXM5 at 926.6 GTexel/s versus 617.8 GTexel/s, though this metric matters less for compute-focused server accelerators. The pixel rate slightly favors the H20 at 47.52 GPixel/s versus 42.12 GPixel/s, a 13% edge that reflects its higher clock speed.

Memory bandwidth favors the H20 by a 20% margin: 4.03 TB/s versus 3.36 TB/s. The H20 also leads in memory capacity by 16 GB. For workloads that stream large tensors or require frequent memory access, the H20's wider 6144-bit bus provides an advantage. However, the H800 SXM5's compute density means it can process more data per memory transaction. The clock speeds show the H20 running at 1830 MHz base and 1980 MHz boost, versus 1095 MHz base and 1755 MHz boost for the H800 SXM5. The H20's higher clocks partially offset its fewer execution units, but not enough to close the FP32 or FP16 gaps.

Specification Differences

The two cards differ in several recorded fields while sharing others. Clock speeds differ: the H20 runs 1830 MHz base and 1980 MHz boost, while the H800 SXM5 runs 1095 MHz base and 1755 MHz boost. Memory size differs: 96 GB for the H20 versus 80 GB for the H800 SXM5. Memory bus width differs: 6144 bit for the H20 versus 5120 bit for the H800 SXM5. Memory bandwidth differs: 4.03 TB/s for the H20 versus 3.36 TB/s for the H800 SXM5.

Shading units differ: 9984 for the H20 versus 16896 for the H800 SXM5. TMUs differ: 312 for the H20 versus 528 for the H800 SXM5. Tensor cores differ: 312 for the H20 versus 528 for the H800 SXM5. Pixel rate differs: 47.52 GPixel/s for the H20 versus 42.12 GPixel/s for the H800 SXM5. Texture rate differs: 617.8 GTexel/s for the H20 versus 926.6 GTexel/s for the H800 SXM5. FP32 performance differs: 39.54 TFLOPS for the H20 versus 59.30 TFLOPS for the H800 SXM5. FP16 performance differs: 79.07 TFLOPS (2:1) for the H20 versus 237.2 TFLOPS (4:1) for the H800 SXM5.

TDP differs: 500 W for the H20 versus 700 W for the H800 SXM5. Suggested PSU differs: 900 W for the H20 versus 1100 W for the H800 SXM5. Power connectors differ: the H800 SXM5 lists an 8-pin EPS connector, while the H20 lists none. Release dates differ: 2024-01-31 for the H20 versus 2023-03-20 for the H800 SXM5. The API fields differ in notation: the H20 lists N/A for DirectX, OpenGL, and Vulkan, while the H800 SXM5 lists null values.

Shared specifications include the GH100 chip, Hopper architecture, TSMC 5 nm process, 80,000 million transistors, 814 mm² die size, 98.3M per mm² transistor density, 24 ROPs, HBM3 memory type, 1313 MHz memory clock with 5.3 Gbps effective speed, SXM module slot width, PCIe 5.0 x16 bus interface, no display outputs, active production status, Server Ada predecessor, Server Blackwell successor, and no launch MSRP recorded. The ROP count remains identical at 24 for both cards despite the large differences in other execution units.