Short answer: choose RTX A6000 when a tested workload fits inside one active-cooled 48GB ECC workstation GPU and a used or existing Ampere system offers the better complete-system path. Choose H100 only when an 80GB or 94GB Hopper accelerator, HBM bandwidth, MIG or a qualified data-center platform solves a measured requirement. H100 is not one interchangeable card: PCIe 80GB, SXM 80GB and H100 NVL 94GB require different hosts, cooling, power and interconnect planning.
The decision in one minute
- Choose RTX A6000 first: the complete workload fits below 48GB with headroom, an active display-capable workstation card is required, and the exact used or installed card passes condition checks.
- Choose H100 first: the workload crosses 48GB or requires a qualified Hopper server feature, and you have verified the exact PCIe, SXM or NVL system.
- Do not infer speed: 768GB/s, 2TB/s, 3.35TB/s and 3.9TB/s are manufacturer bandwidth specifications, not local-LLM tokens-per-second results.
RTX A6000 vs H100 specifications
| Product | Memory | Published bandwidth | Power | Deployment |
|---|---|---|---|---|
| RTX A6000 | 48GB GDDR6 with ECC | 768GB/s | 300W maximum power | Active, display-capable, 10.5-inch dual-slot workstation card; two-card NVLink support |
| H100 PCIe | 80GB HBM2e | 2TB/s in NVIDIA’s original datasheet | 350W maximum; exact configurations vary | Passive full-height dual-slot data-center PCIe accelerator |
| H100 SXM | 80GB HBM3 | 3.35TB/s on NVIDIA’s current product page | Up to 700W, configurable | SXM module for compatible HGX/DGX platforms |
| H100 NVL | 94GB HBM3 | 3.9TB/s | 350–400W, configurable | Dual-slot air-cooled PCIe data-center product |
Capacity: 48GB versus 80GB or 94GB
An 80GB H100 exposes 32GB more nominal memory than RTX A6000; H100 NVL exposes 46GB more. That can change whether model files, KV cache, runtime workspaces and concurrency fit on one device. It does not automatically make H100 faster, easier to deploy or better value. If a workload fits comfortably inside 48GB, the simpler active-workstation card can remain the more relevant candidate.
For a 70B-class workload, calculate the exact artifact, context, cache precision and concurrency with the LLM VRAM calculator and 70B VRAM guide. A nominal capacity or parameter label is not proof of runtime fit.
Exact Qwen3.5 boundaries on 48GB, 80GB and 94GB
| Complete artifact | Files | RTX A6000 48GB | H100 80GB | H100 NVL 94GB |
|---|---|---|---|---|
| Qwen3.5-35B-A3B community Q8_0 plus F16 projector | 37.802GB | 10.198GB margin | 42.198GB margin | 56.198GB margin |
| Qwen3.5-35B-A3B official BF16 | 71.904GB | Does not fit by files | 8.096GB margin | 22.096GB margin |
| Qwen3.5-122B-A10B official GPTQ-Int4 | 78.864GB | Does not fit by files | 1.136GB; unsafe boundary | 15.136GB margin |
| Qwen3.5-122B-A10B community Q4_K_M plus F16 projector | 77.446GB | Does not fit by files | 2.554GB; unsafe boundary | 16.554GB margin |
| Qwen3.5-122B-A10B official FP8 | 127.163GB | Does not fit | Does not fit | Does not fit |
| Qwen3.5-122B-A10B community Q8_0 plus F16 projector | 130.781GB | Does not fit | Does not fit | Does not fit |
| Qwen3.5-122B-A10B official BF16 | 250.173GB | Does not fit | Does not fit | Does not fit |
RTX A6000 holds the listed 35B Q8-plus-projector files with 10.198GB of nominal room, but not the official 35B BF16 checkpoint. An 80GB H100 changes that BF16 file-fit outcome, yet its two listed 122B 4-bit margins—1.136GB and 2.554GB—are unsafe before runtime allocations. H100 NVL’s 94GB creates materially more file-only room, but none of these three devices fits the listed 122B FP8, Q8-plus-projector or BF16 checkpoint.
Use the Qwen3.5-35B guide, Qwen3.5-122B guide and 48GB-to-96GB capacity hub for artifact provenance and workload limits.
Ampere workstation versus Hopper data center
- RTX A6000: active cooling, display outputs, dual-slot PCIe form factor and 300W power. Verify the exact board, CPU 8-pin/EPS-12V power path, chassis clearance and sustained airflow.
- H100 PCIe: passive cooling requires directed server airflow. An open workstation case is not a validated thermal solution.
- H100 SXM: requires the matching baseboard, server, firmware, cooling and power. A bare module is not a workstation card.
- H100 NVL: uses a PCIe form factor but remains a qualified data-center deployment. “PCIe” does not imply ordinary desktop compatibility.
CUDA generation, MIG and NVLink
- Compute target: RTX A6000 is Ampere; H100 is Hopper compute capability 9.0. Confirm driver, CUDA, framework, runtime and compiled-extension support for the exact environment.
- MIG: H100 can be partitioned into profiles; a process assigned a slice sees the slice’s framebuffer, not automatically the whole GPU. RTX A6000 is not an H100-style MIG product.
- NVLink: RTX A6000 supports a two-card bridge, while H100 interconnect support varies by SKU and platform. In neither case does the interconnect create a transparent pooled-memory device; the runtime must explicitly split or parallelize the workload.
- Generation: Hopper Transformer Engine and peak Tensor Core claims depend on precision, sparsity, kernels and software. They do not establish an application-speed ratio against Ampere.
Used RTX A6000 versus H100 procurement risk
- Require label and part-number photos; distinguish RTX A6000 from RTX 6000 Ada, Quadro RTX 6000 and other similarly named cards.
- Request current device identity, memory-health evidence and a sustained-load result from the exact unit.
- For H100, prove PCIe versus SXM versus NVL identity and whether the offer is a bare accelerator, paired NVL configuration or complete tested system.
- Verify accessories, bridge inclusion, cooling, power cabling, firmware, return terms and shipping protection.
- Compare delivered, working-system cost—not the bare listing price. Use the used-GPU evidence checklist.
Which should you buy?
| Your evidence | Start with |
|---|---|
| Need an active, display-capable 48GB professional workstation GPU | RTX A6000 |
| Need a qualified 80GB or 94GB Hopper data-center deployment | Exact H100 variant |
| Need 35B BF16 file capacity on one device | H100 80GB or 94GB starts above the 71.904GB files; measure the complete runtime |
| Need a 122B 4-bit path | Do not treat H100 80GB’s 1.136GB/2.554GB file margins as safe; evaluate H100 NVL 94GB or a larger tier |
| Need a measured local-inference winner | Run the same reproducible workload |
Choose the next evidence
Review screened observations · Run the workload test · Share a result · Browse source-specific results · Save private return criteria or follow RSS
Official NVIDIA sources
- NVIDIA RTX A6000 specifications
- NVIDIA H100 product page
- NVIDIA H100 GPU datasheet
- NVIDIA H100 PCIe board specification
- NVIDIA MIG supported-GPU table
Reviewed October 25, 2026. Specifications may vary by SKU, revision and configured power mode. HighVRAM has not independently benchmarked this pair. File fit is not measured peak memory, speed, compatibility, availability or value.
Also considering the newest GeForce? Compare RTX 5090 32GB with H100 80GB/94GB using the same capacity-first method.
DGX Spark vs H100: Compare the compact 128GB system directly with H100 in the exact capacity and platform comparison.