Best Local AI Models for Low-End Hardware (Late 2026): How Much VRAM & RAM You Really Need

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Every week there's a new "GPT-level model you can run at home!" headline. Then you download it, and your 8 GB graphics card wheezes, swaps to system RAM, and produces one word every three seconds.
The good news is that late 2026 is the best time ever to run AI locally on modest hardware. Small models like Qwen3.5 9B and Gemma 4 E4B are genuinely useful. Mixture-of-experts models such as gpt-oss-20b and Qwen3.6 35B-A3B punch way above their weight, and Apple Silicon Macs with unified memory have become the budget-friendly secret weapon.
This guide answers the question everyone actually has: "What's the best model I can run on my hardware, and how much VRAM or RAM do I really need?"
Quick Answer: What Can You Run?
Approximate figures for 4-bit quantized models (Q4_K_M or similar) with a modest 4K–8K context:
| Your memory | Best all-round pick | Also great | Feels like |
|---|---|---|---|
| 4–6 GB VRAM or 8 GB RAM (CPU) | Qwen3.5 4B | Gemma 4 E2B / E4B, Llama 3.2 3B | Smart autocomplete, quick Q&A |
| 8 GB VRAM | Qwen3.5 9B | Gemma 4 E4B (higher quant) | Solid daily assistant |
| 12 GB VRAM | Qwen3.5 9B (Q6–Q8, long context) | gpt-oss-20b (partial offload) | Strong assistant, decent coding |
| 16 GB VRAM or 16–24 GB Mac | gpt-oss-20b | Qwen3.5 9B at Q8 | Reasoning, tool use, good coding |
| 24 GB VRAM or 32 GB+ Mac | Qwen3.6 27B or Qwen3.6 35B-A3B | Gemma 4 31B / 26B A4B | Close to last-gen cloud models |
Note: New models land monthly. The memory math below never goes out of date, so learn it once and you can size any future model in ten seconds.
The Memory Math (How to Size Any Model)
A model's memory footprint comes from three things.
1. Weights: parameters × bits per parameter
| Precision | Bytes per parameter | 9B model | 27B model |
|---|---|---|---|
| FP16 / BF16 (full) | 2.0 | ~18 GB | ~54 GB |
| Q8 (8-bit) | ~1.06 | ~9.5 GB | ~29 GB |
| Q4_K_M (4-bit) | ~0.6 | ~5.5 GB | ~16.5 GB |
| Q3 / IQ3 (3-bit) | ~0.45 | ~4 GB | ~12 GB |
Rule of thumb: at 4-bit, a model needs about 0.6 GB per billion parameters. Q4_K_M is the sweet spot: the quality loss versus full precision is small for chat and coding, and it's the default in Ollama and LM Studio.
2. Context (the KV cache)
Every token of conversation history takes memory. For a typical modern 7–9B model, expect very roughly 0.5–1.5 GB per 8K tokens of context, depending on architecture. If you want 32K+ context for long documents, budget several extra GB, or enable KV-cache quantization (OLLAMA_KV_CACHE_TYPE=q8_0 with flash attention on) to roughly halve it.
3. Overhead
Leave ~1 GB for the runtime and, if it's your display GPU, whatever your desktop uses (often 0.5–1.5 GB).
Worked example: Qwen3.5 9B at Q4_K_M is ~6.6 GB as an Ollama download. Add ~1 GB of context and ~0.5 GB of overhead, and you get ~8 GB. It fits an 8 GB card just, with a short context. On a 12 GB card it's comfortable.
Dense vs mixture-of-experts (MoE)
This matters a lot for budget hardware:
- Dense models (Qwen3.6 27B, Gemma 4 31B) use every parameter for every token.
- MoE models (gpt-oss-20b, Qwen3.6 35B-A3B, Gemma 4 26B A4B) store lots of parameters but only activate a few billion per token.
Memory is set by total parameters; speed is set by active parameters. A 35B-A3B model needs the RAM of a 35B model but generates text at roughly the speed of a 3B model. That makes MoE models brilliant on Macs and CPU-only machines, where you have plenty of (slow) memory.
Why Speed Is About Memory Bandwidth
When generating text, the hardware has to read (roughly) all of the active weights from memory for every token. So:
Max tokens/second ≈ memory bandwidth ÷ size of active weights
| Hardware | Approx. bandwidth | 9B Q4 (~5.5 GB) ceiling | 3B-active MoE ceiling |
|---|---|---|---|
| Intel N100 (single-channel DDR5) | ~38 GB/s | ~6 tok/s | ~15–20 tok/s |
| Desktop dual-channel DDR5 | ~80–90 GB/s | ~15 tok/s | ~35–45 tok/s |
| Apple M4 (base) | 120 GB/s | ~20 tok/s | ~50+ tok/s |
| Apple M4 Pro | 273 GB/s | ~45 tok/s | ~90+ tok/s |
| RTX 3060 12 GB | 360 GB/s | ~55 tok/s | n/a (if it fits) |
| RTX 3090 24 GB | 936 GB/s | ~120 tok/s | very fast |
Real-world numbers land at roughly 50–80% of these ceilings. Still, the table explains the most important thing in local AI: a used RTX 3090 is far faster than a new budget card, and an M4 Pro Mac is roughly twice as fast as a base M4 at the same model size.
Want real numbers from a tiny box? We measured an N100 in Running Ollama on Intel N100.
Apple Silicon and Unified Memory: The Budget Secret Weapon
On a PC, your GPU can only use its own VRAM, usually 8–16 GB on affordable cards. Anything that doesn't fit spills into system RAM and slows to a crawl.
On an Apple Silicon Mac, CPU and GPU share one pool of unified memory. A Mac with 32 GB can hand ~24 GB to the GPU. A graphics card with 24 GB of VRAM costs more than that whole Mac mini.
How much of a Mac's memory can the GPU use?
By default macOS lets the GPU "wire" roughly 65–75% of total RAM (the exact share depends on the machine). In practice:
| Mac memory | Usable for models (default) | Comfortable model choice |
|---|---|---|
| 8 GB | ~5 GB | Qwen3.5 4B, Gemma 4 E2B. Honestly, skip 8 GB for AI |
| 16 GB | ~10–11 GB | Qwen3.5 9B (Q4–Q6), Gemma 4 E4B |
| 24 GB | ~16–18 GB | gpt-oss-20b, Qwen3.5 9B at Q8 with long context |
| 32 GB | ~22–24 GB | Qwen3.6 35B-A3B (Q4), Qwen3.6 27B (Q4) |
| 48–64 GB | ~36–48 GB | Gemma 4 31B at Q6–Q8, 70B-class models at Q4 (64 GB) |
Power users can raise the limit (it resets on reboot) and leave ~8 GB for macOS:
# Example: let the GPU use up to 26 GB on a 32 GB Mac sudo sysctl iogpu.wired_limit_mb=26624
This isn't an officially supported Apple setting. Push it too far and macOS will start swapping or freeze, so raise it gradually.
Bandwidth by chip (why "Pro" and "Max" matter)
| Chip | Unified memory bandwidth |
|---|---|
| M1 | 68 GB/s |
| M2 / M3 | 100 GB/s |
| M4 | 120 GB/s |
| M5 | 153 GB/s |
| M4 Pro | 273 GB/s |
| M4 Max | 410–546 GB/s |
| M3 Ultra | 819 GB/s |
Newer M5-generation Pro, Max and Ultra chips push these numbers higher still. Check Apple's spec page for the exact model you're considering. For AI, a used M1/M2 Max or Pro with lots of memory can beat a brand-new base-model Mac.
MLX vs llama.cpp on Mac
- llama.cpp / Ollama (GGUF): works everywhere, huge model selection, uses Metal on the GPU.
- MLX (Apple's own framework): often 10–30% faster on Apple Silicon. LM Studio can run MLX models with one click, and Ollama now offers MLX builds of some models too.
If you're on a Mac, try both on your favourite model and keep the faster one.
The Best Models by Tier (Late 2026)
Tier 1: 4–6 GB VRAM, or CPU with 8 GB RAM
- Qwen3.5 4B (~3.4 GB): the best quality you'll get at this size. Good at instructions, summaries, and simple code.
- Gemma 4 E2B / E4B: Google's "effective parameter" models, built for phones and laptops. They also accept images, so you can ask questions about screenshots or photos. Use the QAT (quantization-aware trained) builds for the smallest download.
- Llama 3.2 3B: older, but extremely well supported and very fast on CPU. Still a great pick for an N100 or Raspberry Pi 5.
Use for: Home Assistant voice commands, summarizing notes, autocomplete, quick lookups.
Tier 2: 8 GB VRAM (RTX 3060 Ti / 4060 / 3070)
- Qwen3.5 9B (Q4_K_M, ~6.6 GB): the consensus best model for 8 GB cards in 2026. It handles tool-calling and agents well, and includes a "thinking" mode for harder problems.
- Gemma 4 E4B at Q8: excellent multilingual writing and image understanding.
Watch out: keep context to 4K–8K on 8 GB, or the model spills to system RAM and slows dramatically.
Tier 3: 12 GB VRAM (RTX 3060 12 GB, 4070, B580)
- Qwen3.5 9B at Q6/Q8 with 16–32K context: noticeably sharper than Q4, with room for long documents.
- gpt-oss-20b with a few layers offloaded to RAM: still very usable because it's MoE (only ~3.6B parameters active per token).
The used RTX 3060 12 GB remains the best budget AI card: cheap, power-efficient, and it has more VRAM than many newer mid-range cards.
Tier 4: 16 GB VRAM, or a 24 GB Mac
- gpt-oss-20b: OpenAI's open-weight reasoning model. OpenAI says its native MXFP4 format runs within 16 GB of memory. Strong at step-by-step reasoning, tool use and code, with adjustable reasoning effort (low/medium/high).
- Qwen3.6 35B-A3B at ~3-bit (around 14 GB): squeezes onto 16 GB with a short context, with excellent coding for the size.
Tier 5: 24 GB VRAM (used RTX 3090 / 4090), or a 32 GB+ Mac
This is where local AI starts to feel like last generation's cloud models:
- Qwen3.6 27B (dense, Q4 ~17 GB): top-tier quality for a single GPU, with strong coding and reasoning. Apache 2.0.
- Qwen3.6 35B-A3B (MoE, Q4 ~22 GB): almost as smart and much faster thanks to ~3B active parameters. The perfect Mac model.
- Gemma 4 31B (dense, Q4 ~20 GB) and Gemma 4 26B A4B (MoE): excellent writing, multilingual and vision. Long context (up to 256K).
Check the tags. Model names and download sizes change as new builds are published. Search the Ollama library or LM Studio's model browser for the exact tag and size before you pull.
Getting Started in 5 Minutes
Ollama (Linux, Windows, macOS)
# Install (Linux) curl -fsSL https://ollama.com/install.sh | sh # Pull and chat with a model that fits your tier ollama run qwen3.5:9b # Check how much is on the GPU vs CPU ollama ps
ollama ps is your best friend. If the PROCESSOR column shows something like 40%/60% CPU/GPU, the model doesn't fit. Pick a smaller model, a lower quant, or shorter context.
For a full setup with a ChatGPT-style web interface, follow our Ollama + Open WebUI guide.
LM Studio (easiest on Mac and Windows)
Download LM Studio, search for a model, and it shows a green "fits" or red "too large" badge based on your hardware. On a Mac, prefer the MLX versions.
Give it a voice
Pair your model with Kokoro TTS, a tiny local text-to-speech model, for a fully private voice assistant.
Cheapest Hardware That Actually Works
| Budget route | Memory for AI | Best for |
|---|---|---|
| Existing PC + 32 GB DDR5 | System RAM | Small MoE models on CPU; slow but free |
| Intel N100/N150 mini PC (16 GB) | System RAM | 3–4B models, always-on, ~10 W idle |
| Used RTX 3060 12 GB | 12 GB VRAM | Best price-per-GB of VRAM; Tier 3 |
| Used RTX 3090 24 GB | 24 GB VRAM | Tier 5 performance on a budget (needs a big PSU) |
| Mac mini (24–32 GB) | Unified memory | Quiet, ~5–30 W, MoE models shine |
| Used Mac Studio M1/M2 Max (64 GB) | Unified memory | 70B-class models, high bandwidth |
Avoid: buying a new 8 GB GPU for AI in 2026. It's the most frustrating tier, because everything good is just slightly too big. If you're building a PC, our budget gaming PC guide explains how to stretch for a 12–16 GB card.
Troubleshooting Slow Local AI
It's painfully slow (1–3 tokens/s)
The model is spilling into system RAM. Check ollama ps, then use a smaller quant, a smaller model, or a shorter context window.
It loads, then crashes with out-of-memory
Context is too big. Lower num_ctx, or enable flash attention plus KV-cache quantization.
Answers are rambling or ignore instructions Very small models (under 4B) struggle with complex prompts. Move up a tier, or give shorter, clearer instructions. For "thinking" models, switch thinking off for simple tasks.
Mac shows plenty of free RAM but the model won't load on the GPU
You've hit the default GPU wired-memory limit. Pick a smaller quant, or carefully raise iogpu.wired_limit_mb.
FAQ
Is 8 GB of VRAM enough for local AI? For 4B–9B models at Q4 with short context, yes. Qwen3.5 9B runs well. For anything larger, aim for 12 GB or more.
Can I run local AI without a GPU? Yes. CPU-only works fine for 3–4B models, and MoE models like gpt-oss-20b run surprisingly well on 32 GB of fast DDR5. Expect single-digit to low-double-digit tokens per second.
Is a Mac better than a PC with a GPU for local AI? Per dollar of memory, usually yes: a 32 GB Mac mini runs models no affordable GPU can fit. Per dollar of speed, a used RTX 3090 still wins for models that fit in 24 GB.
What does Q4_K_M mean? It's a 4-bit quantization format from llama.cpp. "K" means it uses k-quant blocks, and "M" is medium quality. It's the best default trade-off between size and quality.
How much RAM do I need alongside the GPU? At least as much system RAM as VRAM, ideally double. 32 GB is the comfortable minimum for a local AI box.
The Bottom Line
You don't need a $2,000 GPU to run genuinely useful AI at home. Match the model to your memory:
- 8 GB → Qwen3.5 9B
- 16 GB → gpt-oss-20b
- 24 GB or a 32 GB Mac → Qwen3.6 27B or 35B-A3B
Then use the bandwidth rule to set realistic speed expectations. Learn the memory math once and you'll be ready for whatever model drops next month.



