GPU Access

Workloads by GPU Class

Draft

This documentation is in draft and under active review. Figures for the Fall 2026 GPU reservation system are not yet published, and some pages describe behavior that has not been verified against a primary source. Confirm any figure with parasol@ucsd.edu before relying on it.

Estimate the GPU memory your work needs, then request the smallest GPU class it fits within, among the classes your workspace can use. See Choosing a Class and Workspace Class Grants. Not every card or slice listed here backs its class in every quarter.

Estimating GPU Memory

A model's weights take a fixed amount of GPU memory for each billion parameters, set by their precision.

Precision of the weights GPU memory per billion parameters
BF16 or FP16 About 2 GB
INT8 or FP8 About 1 GB
4-bit About 0.5 GB

Inference needs the weights plus a cache that grows with the length of the context. Training also needs gradients, optimizer state, and the activations for one batch. Full fine-tuning with the Adam optimizer takes about 16 bytes per parameter before activations, so a 650M-parameter model needs about 10 GB. LoRA (low-rank adaptation) freezes the base weights and trains small adapter matrices, and QLoRA does the same on a base quantized to 4 bits, so both need far less.

The memory figures in the examples are approximate peaks. They vary with batch size, sequence length and LoRA rank. Measure a short trial run with nvidia-smi or torch.cuda.memory_summary() before sizing a long one.

Differences Within a Class

The cards and slices behind one class differ in memory, speed and supported number formats. A medium session can run on a 20 GB slice or a 24 GB card, and a large session on a 40 GB slice or a 48 GB card. A run that fits only the larger device fails with a CUDA out-of-memory error whenever the session lands on the smaller one. Size work for the smallest device listed for the class.

The Turing cards, the RTX 2080 Ti in small and the Titan RTX in medium, have neither BF16 nor FlashAttention 2. Code that requires either fails or runs slower on those cards. FP16 mixed precision runs on every device listed. See GPU Hardware & CUDA.

xsmall

xsmall suits encoder fine-tuning, QLoRA of models up to about 3 billion parameters, and small vision and graph models.

Example Setting Method and approximate memory
Sentiment or topic classification with BERT-base or DistilBERT Course Full fine-tuning
A first instruction-tuning lab with Llama 3.2 3B and a small dataset Course QLoRA, about 3.5 GB
Image classification by transfer learning from ResNet-50 or EfficientNet Course Full fine-tuning
Named-entity recognition on PubMed abstracts with BioBERT or PubMedBERT Research Full fine-tuning
Node or link prediction with a graph neural network on Open Graph Benchmark datasets Research Under 2 GB for most architectures

A 3B model at FP16 needs about 6.5 GB for inference, more than an xsmall slice has. At 8-bit precision it needs about 3.5 GB.

xsmall Hardware

Card or slice Memory Specifications
A30 MIG 1g.6gb 6 GB Ampere

small

small suits QLoRA of 7B to 9B language models, larger vision models, and image-generation LoRA training.

Example Setting Method and approximate memory
Instruction-tuning an 8B or 9B model, such as Llama 3.1 8B or Gemma 2 9B Course QLoRA, about 9 to 10 GB
Zero-shot image retrieval by fine-tuning CLIP Course Full fine-tuning
Adapters for a low-resource language on mBERT or XLM-R Research Adapter training
Image-generation LoRA training on Flux Research QLoRA, about 9 GB

A QLoRA run of an 8B or 9B model is close to the 10 GB of the H100 slice, the smallest small device.

small Hardware

Card or slice Memory Specifications
H100 MIG 1g.10gb 10 GB Hopper
RTX 2080 Ti 11 GB Turing
A30 MIG 2g.12gb 12 GB Ampere

medium

medium suits LoRA of 7B and 8B models without quantization, INT8 LoRA of 13B and 14B models, and vision-language models.

Example Setting Method and approximate memory
LoRA of a 7B model, such as Qwen2.5 7B, without quantization Course BF16 LoRA, about 18 GB
Visual question answering or chart reading with Qwen2-VL 7B or LLaVA 1.6 Course LoRA
Adapting a 14B model, such as Qwen2.5 14B, to a field's literature Research INT8 LoRA, about 16 GB
Protein function prediction with the 3B-parameter ESM-2 model Research Fine-tuning

A 14B model at BF16 needs about 28 GB for its weights alone, more than any medium device has.

medium Hardware

Card or slice Memory Specifications
H100 MIG 2g.20gb 20 GB Hopper
A30 24 GB Ampere
RTX A5000 24 GB Ampere
Titan RTX 24 GB Turing
RTX PRO 6000 MIG 1g.24gb 24 GB Blackwell

large

large suits QLoRA of 30B to 34B models, video generation, and protein structure work.

Example Setting Method and approximate memory
A graduate fine-tuning practicum on Qwen3 32B Course QLoRA, about 22 GB
Video generation at 720p with Wan2.1 or CogVideoX-5B Course Inference
Fine-tuning Qwen2.5-Coder 32B on a lab's bioinformatics pipelines Research QLoRA, about 22 GB
Protein structure prediction with ESMFold, or fine-tuning ESM-2 15B Research Fine-tuning

QLoRA of a 70B model, such as Llama 3.1 70B, needs about 38 to 42 GB. It fits the 48 GB devices, but not reliably the 40 GB slice. A 32B model at BF16 needs about 66 GB for its weights, more than any large device has.

large Hardware

Card or slice Memory Specifications
H100 MIG 4g.40gb 40 GB Hopper
L40S 48 GB Ada Lovelace
RTX PRO 6000 MIG 2g.48gb 48 GB Blackwell

xlarge

xlarge suits fine-tuning 70B models, long-context work, and pretraining experiments.

Example Setting Method and approximate memory
Fine-tuning Llama 3.1 70B or Qwen2.5 72B for an advanced seminar or a thesis Course FP8 LoRA, about 72 GB
Fine-tuning on long documents, with contexts of 128,000 tokens or more Course LoRA
Genomic language models, such as Nucleotide Transformer or HyenaDNA, on sequences of 100,000 bases or more Research Fine-tuning
Continued pretraining of a small model on a domain corpus Research Pretraining
Neural-operator training on fluid-dynamics or climate data with large batches Research Full training

A 70B model at BF16 needs about 140 GB for its weights, more than any single card has. Work across several GPUs is a separate request; see Multiple GPUs.

xlarge Hardware

Card or slice Memory Specifications
H100 PCIe 80 GB Hopper
RTX PRO 6000 Blackwell 96 GB Blackwell