NVIDIA H20 vs NVIDIA H800 PCIe 80 GB Comparison

Head-to-Head Benchmarks

The recorded database contains no benchmark scores for either the NVIDIA H20 or the NVIDIA H800 PCIe 80 GB. Both cards show an average benchmark score of zero and a percentile rank of 50 against all GPUs. With no benchmark entries and no nearest rivals listed, a direct numeric performance comparison cannot be established from the available data. The head-to-head comparison must therefore rely entirely on the specification-level differences documented in the database.

The most striking difference appears in raw compute throughput. The H800 PCIe 80 GB delivers 51.22 TFLOPS FP32, while the H20 reaches 39.54 TFLOPS FP32. That places the H800 roughly 30% higher in single-precision floating-point work. The gap widens dramatically in FP16: the H800 records 204.9 TFLOPS (4:1), compared to 79.07 TFLOPS (2:1) for the H20. The H800 thus offers more than double the half-precision throughput, a critical metric for AI training and inference workloads that rely heavily on reduced-precision math.

Memory bandwidth tells a different story. The H20 uses HBM3 with a 6144-bit bus and reaches 4.03 TB/s of bandwidth. The H800 PCIe 80 GB uses HBM2e with a 5120-bit bus and delivers 2.04 TB/s. The H20 therefore provides nearly double the memory bandwidth, a decisive advantage for memory-bound workloads such as large model inference, data processing, and certain graph analytics. The H20 also carries 96 GB of memory versus 80 GB on the H800, adding 16 GB of capacity.

Texture and pixel throughput favor the H800. The H800 posts 800.3 GTexel/s against 617.8 GTexel/s for the H20, a lead of roughly 30%. Pixel rates are closer: 47.52 GPixel/s for the H20 versus 42.12 GPixel/s for the H800, giving the H20 a modest 13% edge. The H800 has 456 TMUs and 456 tensor cores, while the H20 has 312 TMUs and 312 tensor cores. Shading units also differ substantially, with the H800 at 14,592 versus 9,984 for the H20.

Clock behavior diverges significantly. The H20 runs a base clock of 1830 MHz and boosts to 1980 MHz. The H800 PCIe 80 GB runs a much lower base of 1095 MHz but boosts to 1755 MHz. The H20's higher base clock suggests sustained performance in steady-state workloads, while the H800's boost behavior indicates a wider dynamic range. Memory clocks also differ: the H20 operates at 1313 MHz with 5.3 Gbps effective, while the H800 runs at 1593 MHz with 3.2 Gbps effective. The H20's higher effective memory speed, combined with its wider bus, explains its bandwidth advantage.

Power consumption favors the H800. The H800 PCIe 80 GB has a TDP of 350 W with a suggested PSU of 750 W. The H20 draws 500 W with a suggested PSU of 900 W. The H800 thus delivers higher FP32 throughput at lower power, indicating better energy efficiency for compute-bound tasks. The H20's higher power draw reflects its larger memory subsystem and higher base clocks.

Physical form factors differ. The H20 ships as an SXM Module, while the H800 PCIe 80 GB is a dual-slot card measuring 268 mm (10.6 inches) in length and 111 mm (4.4 inches) in height. The H800 requires a single 16-pin power connector; the H20 lists no external power connector, relying on the SXM socket. Both cards use PCIe 5.0 x16 for host connectivity and have no display outputs. Both are built on the GH100 chip using TSMC's 5 nm process, with 80,000 million transistors on an 814 mm² die and a transistor density of 98.3 million per mm².

The Verdict

The database shows two distinct design priorities within the same Hopper architecture. The H20 prioritizes memory capacity and bandwidth, offering 96 GB of HBM3 at 4.03 TB/s, along with higher base clocks and a 500 W power envelope. The H800 PCIe 80 GB prioritizes raw compute throughput, delivering 51.22 TFLOPS FP32 and 204.9 TFLOPS FP16, while consuming 350 W. Neither card has benchmark scores in the database, so the verdict rests on specification analysis.

For workloads where memory bandwidth dominates, the H20 is the stronger choice. Its 4.03 TB/s bandwidth is roughly double the H800's 2.04 TB/s, and its 96 GB capacity exceeds the H800's 80 GB. Large language model inference, recommendation systems, and scientific simulations that stream data through memory will benefit from the H20's wider HBM3 interface. The H20's higher base clock of 1830 MHz also suggests steadier performance under sustained memory-heavy loads.

For workloads where compute throughput dominates, the H800 PCIe 80 GB is the stronger choice. Its FP32 output of 51.22 TFLOPS exceeds the H20 by 30%, and its FP16 output of 204.9 TFLOPS more than doubles the H20's 79.07 TFLOPS. Dense matrix operations, deep learning training with large batch sizes, and scientific computing that relies on FP32 or FP16 arithmetic will favor the H800. Its lower TDP of 350 W also makes it easier to integrate into existing server infrastructure.

The H20's SXM form factor targets dense, multi-GPU server configurations where power delivery and cooling are handled by the chassis. The H800's PCIe dual-slot design offers flexibility for workstation or server builds with standard PCIe slots. The database shows no benchmark scores for either card, so the verdict cannot quantify real-world performance differences beyond the specification sheet.

Where Each One Wins

The H20 wins on memory bandwidth. Its 4.03 TB/s is double the H800's 2.04 TB/s. Applications that repeatedly read large datasets, such as high-performance computing simulations, in-memory databases, and large-scale AI inference, will see the H20's memory subsystem as the limiting factor. The H20 also wins on memory capacity at 96 GB versus 80 GB, enabling larger models or larger batch sizes to fit within a single GPU.

The H20 wins on pixel rate. Its 47.52 GPixel/s exceeds the H800's 42.12 GPixel/s by roughly 13%. While neither card targets traditional rasterization, this metric indicates the H20 has a slight edge in output pixel processing, which may matter for certain visualization or image-processing workloads.

The H800 PCIe 80 GB wins on FP32 compute. Its 51.22 TFLOPS is 30% higher than the H20's 39.54 TFLOPS. Scientific computing, finite element analysis, and any workload using single-precision arithmetic will process more data per second on the H800.

The H800 wins decisively on FP16 compute. Its 204.9 TFLOPS (4:1) is more than double the H20's 79.07 TFLOPS (2:1). Deep learning training, which typically uses FP16 or mixed precision, will see substantially faster matrix multiplications on the H800. The H800's 456 tensor cores versus 312 on the H20 reinforce this advantage.

The H800 wins on texture rate. Its 800.3 GTexel/s is 30% higher than the H20's 617.8 GTexel/s. Texture-heavy workloads, such as certain rendering or image processing pipelines, will favor the H800.

The H800 wins on power efficiency. At 350 W versus 500 W, the H800 delivers 51.22 TFLOPS FP32, while the H20 delivers 39.54 TFLOPS FP32 at a higher power draw. The H800 also has a lower suggested PSU requirement of 750 W versus 900 W.

FAQ

Q: Which GPU has higher FP32 performance?

A: The NVIDIA H800 PCIe 80 GB, at 51.22 TFLOPS, compared to the H20's 39.54 TFLOPS.

Q: Which GPU has more memory bandwidth?

A: The NVIDIA H20, with 4.03 TB/s over a 6144-bit HBM3 interface, versus 2.04 TB/s over a 5120-bit HBM2e interface on the H800.

Q: Which GPU has more memory capacity?

A: The NVIDIA H20, with 96 GB, compared to 80 GB on the H800 PCIe 80 GB.

Q: What are the power requirements for each GPU?

A: The H20 has a TDP of 500 W with a suggested PSU of 900 W. The H800 PCIe 80 GB has a TDP of 350 W with a suggested PSU of 750 W.

Q: Which GPU has more tensor cores?

A: The H800 PCIe 80 GB, with 456 tensor cores, versus 312 on the H20.

Q: What are the form factors of these two GPUs?

A: The H20 is an SXM Module. The H800 PCIe 80 GB is a dual-slot PCIe card measuring 268 mm by 111 mm.

Architecture Differences

Both GPUs use the GH100 chip on the Hopper architecture, fabricated by TSMC on a 5 nm process. Both have 80,000 million transistors on an 814 mm² die, yielding a transistor density of 98.3 million per mm². The architecture generation is identical: Server Hopper (Hxx) for both, with the same predecessor (Server Ada) and successor (Server Blackwell).

The memory systems differ fundamentally. The H20 uses HBM3 with a 6144-bit bus and 96 GB capacity. The H800 PCIe 80 GB uses HBM2e with a 5120-bit bus and 80 GB capacity. The H20's memory clock runs at 1313 MHz with 5.3 Gbps effective, while the H800's memory clock runs at 1593 MHz with 3.2 Gbps effective. The H20's wider bus and faster effective speed create a 4.03 TB/s bandwidth advantage.

Compute resources differ in count. The H20 has 9,984 shading units, 312 TMUs, 24 ROPs, and 312 tensor cores. The H800 has 14,592 shading units, 456 TMUs, 24 ROPs, and 456 tensor cores. The H800 thus has 46% more shading units, 46% more TMUs, and 46% more tensor cores. Both have identical ROP counts at 24.

Clock behavior differs by design. The H20 has a base clock of 1830 MHz and a boost clock of 1980 MHz. The H800 has a base clock of 1095 MHz and a boost clock of 1755 MHz. The H20's base clock is 67% higher than the H800's, while the H800's boost clock is 11% lower than the H20's. This suggests the H20 is tuned for sustained throughput, while the H800 relies on boost behavior.

The FP16 ratio differs. The H20 delivers 79.07 TFLOPS FP16 at a 2:1 ratio, meaning its FP16 throughput is exactly double its FP32. The H800 delivers 204.9 TFLOPS FP16 at a 4:1 ratio, meaning its FP16 throughput is four times its FP32. This indicates the H800 has a more aggressive reduced-precision acceleration path.

Both cards have no display outputs and no supported graphics APIs (DirectX, OpenGL, Vulkan all list N/A or null). Both use PCIe 5.0 x16 for host connection. The H20 carries no external power connector, while the H800 uses a single 16-pin connector.

Specification Differences

Memory type: H20 uses HBM3; H800 uses HBM2e.

Memory size: H20 has 96 GB; H800 has 80 GB.

Memory bus width: H20 uses 6144 bit; H800 uses 5120 bit.

Memory bandwidth: H20 achieves 4.03 TB/s; H800 achieves 2.04 TB/s.

Memory clock: H20 runs at 1313 MHz (5.3 Gbps effective); H800 runs at 1593 MHz (3.2 Gbps effective).

Shading units: H20 has 9,984; H800 has 14,592.

TMUs: H20 has 312; H800 has 456.

Tensor cores: H20 has 312; H800 has 456.

Base clock: H20 at 1830 MHz; H800 at 1095 MHz.

Boost clock: H20 at 1980 MHz; H800 at 1755 MHz.

FP32 throughput: H20 at 39.54 TFLOPS; H800 at 51.22 TFLOPS.

FP16 throughput: H20 at 79.07 TFLOPS (2:1); H800 at 204.9 TFLOPS (4:1).

Pixel rate: H20 at 47.52 GPixel/s; H800 at 42.12 GPixel/s.

Texture rate: H20 at 617.8 GTexel/s; H800 at 800.3 GTexel/s.

TDP: H20 at 500 W; H800 at 350 W.

Suggested PSU: H20 at 900 W; H800 at 750 W.

Form factor: H20 is SXM Module; H800 is dual-slot PCIe.

Power connector: H20 lists none; H800 uses 1x 16-pin.

Dimensions: H20 lists none; H800 measures 268 mm (10.6 inches) long and 111 mm (4.4 inches) high.

Release date: H20 released 2024-01-31; H800 released 2023-03-20.