The Kaitchup – AI on a Budget

The Kaitchup – AI on a Budget

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The Kaitchup – AI on a Budget
The Kaitchup – AI on a Budget
RTX 6000 Pro vs H100 & A100: Best Single-GPU Choice for Fast, Low-Cost LLM Fine-Tuning

RTX 6000 Pro vs H100 & A100: Best Single-GPU Choice for Fast, Low-Cost LLM Fine-Tuning

Faster, cheaper single-GPU training

Benjamin Marie's avatar
Benjamin Marie
Jun 16, 2025
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The Kaitchup – AI on a Budget
The Kaitchup – AI on a Budget
RTX 6000 Pro vs H100 & A100: Best Single-GPU Choice for Fast, Low-Cost LLM Fine-Tuning
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In our last deep dive, the RTX 5090 came out as the fastest GPU for single-GPU workloads under 32 GB of VRAM, perfect for fine-tuning and inference at smaller scales.

Fine-Tuning and Inference with an RTX 5090

Fine-Tuning and Inference with an RTX 5090

Benjamin Marie
·
Mar 24
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But once you push into full LLM training territory, 32 GB feels cramped. Parameter-efficient tuning methods like LoRA or QLoRA help, but they’re not always enough when you want maximum accuracy and minimal compromises.

That’s where the RTX 6000 Pro enters the picture. Same core architecture as the 5090, triple the memory (96 GB), and a surprising rental price: just $1.79/hour on RunPod (referral link), only slightly more than an A100, and far less than an H100.

On paper, it sounds almost too good to be true. But here’s the catch:

  • Raw specs don’t tell the full story. Some GPUs underperform their numbers.

  • Environment setup can make or break your speed, especially with vLLM and FlashAttention.

  • Pricing sweet spots like this often vanish in weeks as demand spikes. Note (August 10th, 2025): Since I wrote this article, the cost of the RTX 6000 Pro increased on almost all platforms that I check, e.g., from $1.79/hour to $1.96/hour on RunPod!

I ran full head-to-head benchmarks, A100 vs H100 vs RTX 6000 Pro, across QLoRA, LoRA, and full fine-tuning, using Qwen3 as our test case.

In this article, you will find how to:

  • Cut costs by 30–40% without losing speed

  • Avoid multi-day debugging of PyTorch + vLLM on RTX 6000 Pro

  • Lock in a rental setup that just works before prices climb

The following notebook shows how to set up the environment for the RTX 6000 Pro and fine-tune LLMs (full, LoRA, and QLoRA), using Qwen3 for the examples:

Get the notebook (#171)

Comparing the RTX 6000 Pro to the H100 and A100: Key Specifications

As mentioned earlier, both the RTX 6000 Pro and the RTX 5090 are built on the same GB202 chip, NVIDIA’s flagship Blackwell architecture. However, the two cards are configured quite differently:

  • Compute Configuration: The RTX 6000 Pro unlocks more of the chip, featuring 24,064 CUDA cores (vs. 21,760 on the RTX 5090). It also doubles the memory interface to support 96 GB of ECC GDDR7.

  • Professional Features: Unlike the consumer-grade RTX 5090, the RTX 6000 Pro includes ECC memory, Quadro-class drivers, Multi-Instance GPU (MIG) capabilities, and ships with certified pro firmware.

  • Thermal & Use Case Differences: The RTX 5090 is a 575 W card built for gaming and enthusiast workloads, with 32 GB of GDDR7. In contrast, the RTX 6000 Pro is optimized for sustained 600 W compute loads and is distributed through NVIDIA's professional channel partners.

From a practical standpoint, these differences may not matter much for model training or inference workloads, except for the memory. With 3x more VRAM, the RTX 6000 Pro opens the door to single-GPU full fine-tuning of larger models without needing complex offloading or quantization tricks.

Of course, this comes at a cost: the RTX 6000 Pro typically now sells for 3~4x the price of the RTX 5090 (if you can find one…).

When comparing the RTX 6000 Pro to data center GPUs like the H100 and A100, however, the differences become far more striking.

Here’s a side-by-side comparison of their main specifications:

Note: For this comparison, I chose to show the PCI Express versions. Specifications can widely vary for NVL and SXM versions that are more suitable for data centers. The H100 SXM versions are much better and perform close to the RTX 6000 Pro, but for a much higher cost. I made a comparison of PCIe vs SXM vs NVL in this article.

On paper, the RTX 6000 Pro appears quite compelling. It features more CUDA and Tensor cores than the H100, and it comes with 16 GB more memory. However, it’s important to understand that they are using different types of memory.

The RTX 6000 Pro uses GDDR7, a high-speed memory type typically found in gaming and workstation GPUs. Mounted on the PCB surrounding the GPU die, GDDR7 achieves impressive bandwidths, ~1.6 TB/s, by relying on high clock speeds over a narrower memory bus. It offers great performance-per-dollar as it is easier to manufacture.

In contrast, both the A100 and H100 use HBM2e, a high-bandwidth memory that is stacked directly on the GPU package using through-silicon vias (TSVs). With a much wider 4,096-bit interface, HBM2e delivers 2.0 TB/s of bandwidth at significantly lower latency and power per bit.

In multi-GPU configurations, the H100’s lower power consumption and higher memory efficiency can result in significantly better overall performance per watt than the RTX 6000 Pro.

That said, this article focuses exclusively on single-GPU scenarios, where the RTX 6000 Pro’s combination of high tensor core count, massive memory, and lower cost makes it a standout option.

We’ll now validate these assumptions through empirical benchmarks.

Set Up PyTorch, FlashAttention, Transformers, etc., for the RTX 6000 Pro

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