Quick Answer
For running local LLMs (Llama 3, Mistral, Gemma) on a 1440p ultrawide PC in SA, VRAM is the critical factor — each billion parameters in an LLM requires approximately 2GB of VRAM at 4-bit quantisation. An RTX 4080 Super 16GB (R30,000) runs 7B–13B models comfortably; an RTX 4090 24GB (R38,000) handles 13B–30B models. The minimum practical setup starts at R35,000–R45,000.
LLM VRAM Requirements for SA Builders
| Model Size | Quantisation | VRAM Required | GPU Recommendation |
|---|---|---|---|
| 7B (Llama 3 7B) | 4-bit | ~4GB | RTX 4060 8GB |
| 13B (Llama 3 13B) | 4-bit | ~7GB | RTX 4070 12GB |
| 30B | 4-bit | ~16GB | RTX 4080 Super 16GB |
| 70B | 4-bit | ~40GB | Not single GPU — requires RTX 4090 |
For most SA users running LLMs locally: the RTX 4070 Ti Super 16GB (~R24,000) is the sweet spot — handles Llama 3 13B comfortably and manages small 30B models at reduced context length.
Minimum 1440p Ultrawide LLM Build (~R40,000–R50,000)
- GPU: RTX 4070 Ti Super 16GB (~R24,000) — 16GB VRAM for 13B–20B models at 4-bit
- CPU: Ryzen 7 7700X (~R7,200) — RAM throughput (CPU offload for larger models)
- RAM: 64GB DDR5-6000 (~R7,800) — LLM CPU offload for oversized models requires large system RAM
- Storage: 2TB NVMe (~R3,200) — model weight files for 13B models are 7–10GB; larger models 20–60GB
- B650 board (
R3,500), 750W PSU (R1,800), case (~R1,200) - Total: ~R48,700
FAQ
What GPU VRAM is needed for running Llama 3 locally in SA?
Llama 3 7B at 4-bit quantisation requires approximately 4GB VRAM — runnable on an RTX 4060 8GB (R8,500). Llama 3 13B at 4-bit needs ~7GB VRAM; the RTX 4070 12GB (R16,500) is the comfortable minimum for 13B models with some context length headroom.
Can I run a 30B LLM on an RTX 4080 Super in SA?
Yes — Mistral 30B or similar at 4-bit quantisation uses approximately 16–17GB VRAM. The RTX 4080 Super 16GB (~R30,000) can load it at reduced context length (4K–8K tokens). For full 32K context length on 30B models, the RTX 4090 24GB is required.
What software is best for running local LLMs on an Nvidia GPU in SA?
Ollama is the simplest local LLM runner — supports CUDA acceleration on all RTX 40-series cards, free and open-source, runs from command line or a local web UI. LM Studio provides a GUI interface. Both are free and work with GGUF quantised model files from HuggingFace. No cloud subscription required once the model is downloaded.
local LLMs on an RTX GPU in SA, use 4-bit GGUF quantisation files (Q4_K_M format) rather than 8-bit — 4-bit provides 90%+ of the quality of the full-precision model at half the VRAM cost, enabling you to run larger models on the same GPU. Llama 3 13B at Q4_K_M runs on an RTX 4070 12GB where the Q8 version would require 15GB.
