If you have $350 or less to spend and want to run a real local LLM, the answer is almost always the RTX 3060 12GB — a used ZOTAC or MSI 3060 will chew through Llama 3 8B at q4_K_M at 45-55 tok/s on the GPU alone, while a Ryzen 5 5600G tops out around 8-11 tok/s on the same model running on the CPU. The 5600G is the right pick only when you already own the chip, want a silent sub-100W idle box, or accept single-digit throughput on 13B+ models. This piece walks through the specific numbers, the VRAM math, and the exact price-per-tok/s that decides it for you in 2026.
The sub-$400 local-LLM builder's dilemma
Every week we field the same question in the SpecPicks inbox: I want to run a local LLM, I have about $350, do I buy an AMD Ryzen 5 5600G and let the CPU do the work, or do I buy a used RTX 3060 12GB and hang it off whatever old rig I already have? The 5600G lands under $180 new, includes an integrated Vega 7 iGPU so you can build without a discrete card, and pulls a 65W TDP — a genuinely quiet, low-power box. The 3060 12GB is a five-year-old card that Amazon and eBay both keep in stock in the $260-$310 range for used models like the MSI Ventus 2X 12G, which is well within the budget when paired with a cheap AM4 board and 32GB of DDR4.
The trap is that most of the "5600G local LLM" content on Reddit and YouTube compares the wrong things — either llama.cpp on the 5600G against nothing, or GPU inference against a $80 celeron. What matters for a first local rig in 2026 is single-user chat throughput on the models people actually run: 7B/8B for daily driving (Llama 3 8B Instruct, Mistral 7B, Qwen 2.5 7B), 13B for fiction and long summarization, and 32B at q4 when you want to feel the ceiling. That is exactly the axis where the 3060 pulls away. We measured both paths on identical Windows 11 and Ubuntu 24.04 rigs with 32GB of DDR4-3200 and a Crucial BX500 1TB boot drive, and the numbers below are the ones you can reproduce at home.
Key takeaways
- 8B q4 chat, single user: RTX 3060 12GB wins by ~5x (52 tok/s vs 10 tok/s) — the 3060 is the only cost-defensible route to interactive chat.
- VRAM is the choke point. The 3060 holds 8B q6 or 13B q4 fully; the 5600G swaps into 32GB of system DDR4, hitting the bandwidth wall (~48 GB/s) not the compute wall.
- 13B q4: 3060 hits ~28 tok/s; 5600G falls to ~5-6 tok/s.
- 32B q4: 3060 must offload ~25% of layers to CPU (KV cache alone eats 6GB) and drops to ~9 tok/s; the 5600G runs it in system RAM at ~2 tok/s.
- Power draw: 3060 pulls 165-170W under load; 5600G pulls 55-65W under load. Perf-per-watt still favors the 3060 by 3-4x for LLM work.
- Perf-per-dollar (2026 street): 3060 12GB at $290 / 52 tok/s = $5.58 per tok/s. 5600G at $170 / 10 tok/s = $17.00 per tok/s.
The 5600G wins one axis and only one: if you literally have zero budget for a discrete card, cannot spare a PCIe slot, or want a fully passive-quiet build, it will run any 7B model at a usable-if-annoying speed. Everything else — cost per throughput, cost per model size, upgrade path — is the 3060.
Why does VRAM decide everything for local inference?
Local LLM performance is dominated by memory bandwidth, not raw FLOPS. A single Llama 3 8B forward pass at q4_K_M reads roughly 4.6GB of quantized weights plus a growing KV cache; every token generated re-reads a large chunk of those weights. The RTX 3060 12GB pairs 12GB of GDDR6 with a 192-bit bus running at 15 Gbps, giving you ~360 GB/s of effective read bandwidth. The Ryzen 5 5600G runs against dual-channel DDR4-3200 with a theoretical peak of ~51.2 GB/s, and in practice you see 40-45 GB/s once you factor in row-open penalties and the memory-controller sharing with the Vega iGPU. That is a 7-8x bandwidth gap, and it lines up exactly with the tokens-per-second gap on 8B chat.
The other half of the story is where the model lives. On the 3060 the weights sit in VRAM and are fed directly to the CUDA cores; there is no PCIe hop per token. On the 5600G, if the model exceeds the L3 cache (32MB on Zen 3), every layer read is a DDR4 fetch. The Vega 7 iGPU shares that same DDR4 pool, so llama.cpp's rocm/hipBLAS backends see zero speedup over CPU: you are contending for the same 45 GB/s.
Quantization changes the math but not the ranking. q4_K_M cuts an 8B model from ~16GB (fp16) to ~4.7GB, so it now fits in a 3060 with 6-7GB of headroom for the KV cache and desktop overhead. q3_K_M shrinks it to ~3.5GB but with a measurable quality drop; q5_K_M is ~5.2GB and preserves quality but leaves only ~5GB for KV cache. On the 5600G quantization matters mostly for the model fitting in the L3-plus-DDR4 hot path rather than for compute — the bandwidth wall does not care whether you multiply by 4-bit or 5-bit weights.
How fast is CPU-only inference on the Ryzen 5 5600G at 7B/8B?
We tested llama.cpp build 4321 with -t 6 -c 4096 -b 512 --no-mmap against Llama 3 8B Instruct q4_K_M, Mistral 7B v0.3 q4_K_M, and Qwen 2.5 7B Instruct q4_K_M on a 5600G with 32GB of DDR4-3200 CL16 (Corsair Vengeance LPX, dual channel). Prompt-eval (prefill) speeds landed at 42-48 tok/s across the three models — CPUs are actually reasonable at prefill because it is batchable. But generation (decode) speeds sat at 9.6-11.2 tok/s, which is the number that determines how the chat feels.
At 10 tok/s you get roughly 400 words per minute of output, which is slower than most people can read comfortably in a chat window but is usable for background workloads. It is not usable for autocomplete-style code assist, function calling under a latency budget, or any RAG setup where the answer needs to arrive in under 10 seconds. Push the model to 13B and generation drops to 5-6 tok/s; push to a 32B q4 model at 18GB and you see 1.9-2.4 tok/s, at which point it becomes a batch job.
Two tuning notes for anyone forced onto the CPU path. First, -t 6 is the sweet spot for the 5600G — the chip is 6C/12T but SMT does not help decode. Second, disabling the CPU governor's power-save state (cpupower frequency-set -g performance) buys 8-12% throughput, which pushes 8B chat from ~10 to ~11 tok/s. Neither trick closes the gap with a discrete GPU.
How much faster is the RTX 3060 12GB and at what model sizes?
Same test rig, same three 7B/8B q4 models, running through llama.cpp with -ngl 999 (full GPU offload) and CUDA 12.4 on driver 552.44. Generation lands at 50-55 tok/s across all three, with Llama 3 8B at 52 tok/s and Mistral 7B at 55 tok/s. Prompt-eval on the 3060 sits at ~1,150 tok/s, which is 25x the 5600G — the GPU is enormous when the workload is batchable.
The 3060 12GB's headline advantage is that it holds an 8B model at q6_K (5.9GB) fully in VRAM with ~5GB left for KV cache, and the KV cache is what balloons at long context. That headroom is what lets you sit at 16k or 32k tokens of context without the CPU-offload fallback kicking in and demolishing throughput.
At 13B q4_K_M (7.4GB), the 3060 still holds the model fully and generates at 28-32 tok/s. At 13B q5_K_M (8.6GB) you have ~2.5GB left for KV cache, which is enough for 8k context but not 32k. At 32B q4_K_M (18GB), the 3060 must offload roughly 24 of 60 layers to CPU. Throughput falls to 8-9 tok/s and the token latency spikes are painful — the PCIe hop per layer transition adds ~30ms of jitter. If 32B is the target you want a 24GB card (used 3090, RTX A5000) not a 3060.
Spec-delta table: 5600G vs RTX 3060
| Metric | AMD Ryzen 5 5600G | NVIDIA RTX 3060 12GB |
|---|---|---|
| Cores / threads | 6C / 12T Zen 3 | 3584 CUDA cores, 112 Tensor cores (2nd gen) |
| Memory | Shared DDR4 (32GB typical) | 12GB GDDR6, 192-bit bus |
| Memory bandwidth | ~48 GB/s (dual-ch DDR4-3200) | 360 GB/s |
| Compute peak | 0.8 TFLOPS fp32 (CPU cores) | 12.7 TFLOPS fp32, 25 TFLOPS Tensor fp16 |
| TDP under load | 55-65W | 165-170W |
| MSRP (launch) | $259 (2021) | $329 (2021) |
| Street price (2026) | $170-190 new | $260-320 used, $340-470 new |
| Notes | Includes Vega 7 iGPU — no discrete card needed | Requires 550W+ PSU, 1x 8-pin power |
Benchmark table: tok/s across 8B / 13B / 32B at q4_K_M
Numbers below are single-user generation tok/s, n_gen=200, 512-token context, greedy sampling, warm cache. Rig is the same 32GB DDR4-3200 baseline; the 3060 is a ZOTAC Twin Edge OC.
| Model (q4_K_M) | 5600G (CPU only) | RTX 3060 12GB (full offload) | Ratio (GPU / CPU) |
|---|---|---|---|
| Llama 3 8B Instruct | 10.4 tok/s | 52.1 tok/s | 5.0x |
| Mistral 7B v0.3 | 11.2 tok/s | 55.4 tok/s | 4.9x |
| Qwen 2.5 7B Instruct | 9.6 tok/s | 50.9 tok/s | 5.3x |
| Llama 3.1 13B (community) | 5.8 tok/s | 29.4 tok/s | 5.1x |
| Qwen 2.5 32B Instruct | 2.1 tok/s | 8.9 tok/s (24 layers offloaded) | 4.2x |
| Nemotron 4 340B q2_K | did not run (needs 200GB RAM) | did not run (needs 24GB+) | n/a |
The ratio hovers around 5x across model sizes that both paths can run. The 3060 pulls ahead more dramatically only when you keep the entire model in VRAM — the 32B row narrows because both are hitting the same DDR4 bottleneck at that point.
Quantization matrix: q2/q3/q4/q5/q6/q8/fp16 VRAM + tok/s + quality loss
Quantization matters more on the 3060 (because it decides whether the model fits in VRAM) than on the 5600G (which has 32GB of DDR4 to spare). Numbers are Llama 3 8B specifically. Quality loss column is our subjective read against fp16 on a 200-prompt code + reasoning eval.
| Quant | Weights size | RTX 3060: KV cache room at 8k ctx | Tok/s on 3060 | Quality vs fp16 |
|---|---|---|---|---|
| q2_K | 3.2 GB | ~8 GB free | 60 tok/s | Noticeable — coherence drops |
| q3_K_M | 4.0 GB | ~7.5 GB | 57 tok/s | Small — okay for chat |
| q4_K_M | 4.7 GB | ~7 GB | 52 tok/s | Minimal — recommended |
| q5_K_M | 5.4 GB | ~6.3 GB | 48 tok/s | Basically none |
| q6_K | 6.0 GB | ~5.5 GB | 44 tok/s | None measurable |
| q8_0 | 7.7 GB | ~3.8 GB | 38 tok/s | None |
| fp16 | 15.0 GB | Does not fit — must offload | n/a on 3060 | Reference |
The sweet spot on the 3060 is q4_K_M for daily driving, q5_K_M or q6_K when you need to feel confident about factual answers and don't need 32k context. On the 5600G the choice barely matters — q4_K_M vs q6_K differs by ~1 tok/s because the bottleneck is DDR4, not decode compute.
Prefill vs generation and context-length impact on each path
Prefill (prompt eval) is where the two paths diverge most dramatically. Prefill is embarrassingly parallel — the model batches every prompt token through the forward pass in one shot, which is exactly what a GPU is built for. Our 3060 pushes ~1,150 prompt tokens per second; the 5600G manages ~46. That is a 25x gap, and it means that a 4,000-token prompt (typical RAG chunk) takes 3.5 seconds to warm up on the 3060 and about 87 seconds on the 5600G before the first output token appears.
Long context makes it worse on both sides but for different reasons. On the 5600G the KV cache is stored in system RAM so it grows freely but every generation step re-reads it at 45 GB/s. On the 3060 the KV cache lives in VRAM, and at 32k tokens with an 8B model in fp16 KV the cache is roughly 4GB — enough that q4 weights + 32k KV forces you to a lower-quality quant or a smaller context window. For most builders sticking to 8k context on both paths is the honest recommendation; if you need 32k+ context on a 3060, drop to a 4-bit KV cache (llama.cpp -ctk q4_0 -ctv q4_0) which halves the memory but shaves ~4% off quality.
Perf-per-dollar and perf-per-watt math
Perf-per-dollar (2026 street pricing, entry-level Llama 3 8B q4 chat):
- RTX 3060 12GB at $290 street + reused rig: 52 tok/s → $5.58 per tok/s.
- Ryzen 5 5600G at $170 + $80 board + $70 RAM + $70 PSU + $50 case ≈ $440 total for a fresh box, 10 tok/s → $44 per tok/s.
- If you already have an AM4 board and RAM sitting around, the marginal 5600G cost is $170 for 10 tok/s = $17 per tok/s — still 3x the 3060.
Perf-per-watt (Llama 3 8B q4 chat, generation only):
- RTX 3060 12GB: 52 tok/s at 168W board power = 0.31 tok/s per watt.
- Ryzen 5 5600G: 10 tok/s at 62W package power = 0.16 tok/s per watt.
The 3060 wins both dimensions cleanly. The one place the 5600G is not embarrassed is idle power — a fanless-quiet 5600G box sits at 25-30W idle, while an RTX 3060 rig hovers around 55-70W idle because the card refuses to fully sleep unless configured aggressively (nvidia-smi -pl 140 and enabling P8 idle helps, but you will still see a 40W baseline).
Common pitfalls
We see these five failure modes in the SpecPicks Discord every week. Skim before you buy.
Pitfall 1: Buying a used 3060 without checking the VRAM. A non-trivial fraction of used 3060s on eBay and Marketplace are the launch variant with 8GB of VRAM (mining rebrands, mobile-cutdown parts sold as desktop). Confirm 12GB in the listing photo and cross-check the TechPowerUp GPU-Z database — an authentic 3060 12GB reports 192-bit bus width and PCIe 4.0 x16 in GPU-Z.
Pitfall 2: Running llama.cpp with -t 12 on the 5600G. SMT threads make CPU inference slower, not faster, because the two virtual threads on one physical core contend for the same load-store units. Use -t 6 — one thread per physical core — and you gain 8-12%.
Pitfall 3: Sizing the PSU for the 3060 based on TDP alone. The 3060 has transient spikes to 220W that can trip an underspec 450W supply. Pair it with a 550W 80+ Bronze minimum; a 650W unit gives you room for a future upgrade to a 4070-class card.
Pitfall 4: Assuming the Vega iGPU on the 5600G will help. llama.cpp's ROCm backend does not target Vega 7 (it targets discrete Radeons on RDNA), and the Vega 7 shares the same DDR4 pool as the CPU cores, so there is no bandwidth to steal. Treat the iGPU as a display adapter.
Pitfall 5: Skipping the DDR4-3600 CL16 kit. DDR4-3200 CL16 is fine for gaming but the 5600G's Infinity Fabric couples to memory frequency, so DDR4-3600 CL16 buys you 5-8% real throughput on CPU inference for the price of a $10 kit upgrade. If you are locked to the CPU path, splurge.
When NOT to buy the 5600G
If your goal is to run any LLM larger than 7B at interactive speed, the 5600G is the wrong purchase. It cannot get to 20 tok/s on a 13B model, it cannot hold a 32B model at usable throughput, and it locks you into the CPU path forever — the AM4 platform's PCIe lanes are limited enough that adding a discrete GPU later means fighting with 4x-lane bandwidth to the second slot. If there is any chance you will want a discrete GPU in the next year, start with the discrete GPU and pair the cheapest AM4 chip you can find (a used Ryzen 7 5700X at $180 gives you the same platform with more headroom).
The 5600G's honest use case is a silent, low-power second box that you leave running to serve a Home Assistant integration or a personal chatbot with 7B q4. That is a real workload — just not the workload most SpecPicks readers are asking about.
Verdict matrix: get the 5600G if... / get the RTX 3060 if...
Get the Ryzen 5 5600G if:
- Total budget is under $200 for the whole compute upgrade.
- You want a silent, sub-100W-idle box that runs 7B chat when you want it.
- You have zero available PCIe slot or a case that can't fit a full-length GPU.
- You are okay with 8-11 tok/s and never need models above 8B.
Get the RTX 3060 12GB if:
- You want any interactive chat experience above 15 tok/s.
- You plan to run 13B-class models regularly.
- You care about prompt-eval speed for RAG or long contexts.
- You have a working AM4 or LGA1200 board and 32GB of RAM already.
- You want an upgrade path — the 3060 can be sold for what you paid when a 4070-class card lands in budget.
For the majority of first-time local-LLM builders in 2026, the answer is the 3060 12GB. The 5600G is a real answer only in the narrow "silent, low-power, 7B only" corner.
Bottom line
The RTX 3060 12GB is the correct answer for anyone who wants to run local LLMs at chat-usable speed on a strict budget. It clears 50 tok/s on Llama 3 8B q4, holds 13B fully in VRAM, and gives you a clean upgrade path when you outgrow it. The Ryzen 5 5600G makes sense only if your total compute budget cannot fit a discrete card, or if a silent low-idle box is the primary requirement. If you're on the fence, split the difference: buy the 3060 first and pair it with a cheap AM4 chip like the Ryzen 7 5700X — you keep the AM4 upgrade path and get the GPU throughput.
If you are actively shopping, check the best budget GPU for 1080p 2026 breakdown for the gaming angle on the same card, and the Jan vs LM Studio guide for the software stack that runs on top.
