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Lab · LLM VRAM · OLMo

Computed

OLMo 2 13B Instruct memory requirements

13.7B parameters — 25.5 GiB of weights at FP16, 7.8 GiB at Q4_K_M, and 800.0 KiB of KV cache per token on top. Solved against 22 real accelerators; 21 of them can hold it.

Parameters

13.7B

13,716,198,400 exactly

Weights, Q4_K_M

7.8 GiB

25.5 GiB unquantized

KV cache

800.0 KiB

per token · 40L × 40 KV × 128

Smallest card (Q4)

12 GB

GeForce RTX 3060 12GB

Weights at each precision

PrecisionBits/weightWeightsSourceNotes
FP16 / BF1616.0025.5 GiBmeasured fileUnquantized. Two bytes per parameter, exactly.
Q8_08.5013.6 GiBmeasured fileEffectively lossless; the usual reference point for quantized quality.
Q6_K6.5710.5 GiBmeasured fileQuality loss is hard to measure on most benchmarks.
Q5_K_M5.699.1 GiBmeasured fileA middle point when Q4 fits with too little room for context.
Q4_K_M4.877.8 GiBmeasured fileThe default choice for local inference — the best size/quality knee.
Q3_K_M3.956.3 GiBmeasured fileMeasurable quality loss. Worth it only to make a model fit at all.

Every accelerator

Largest quant that fits with at least 4k of context, the context it leaves, and the bandwidth ceiling on decode speed. Each row links to the worked page for that pairing.

AcceleratorMemoryBandwidthBest quantMax contextCeiling
Apple M3 Ultra (512GB)512 GB819 GB/sFP16 / BF164,09627 tok/s
H200 141GB (SXM)141 GB4800 GB/sFP16 / BF164,096156 tok/s
Apple M4 Max (128GB)128 GB546 GB/sFP16 / BF164,09618 tok/s
H100 80GB (SXM5)80 GB3350 GB/sFP16 / BF164,096109 tok/s
A100 80GB (SXM)80 GB2039 GB/sFP16 / BF164,09666 tok/s
Jetson AGX Orin (64GB)64 GB204.8 GB/sFP16 / BF164,0967 tok/s
RTX 6000 Ada Generation48 GB960 GB/sFP16 / BF164,09631 tok/s
L40S48 GB864 GB/sFP16 / BF164,09628 tok/s
Apple M4 Pro (48GB)48 GB273 GB/sFP16 / BF164,0969 tok/s
A100 40GB (SXM)40 GB1555 GB/sFP16 / BF164,09651 tok/s
GeForce RTX 509032 GB1792 GB/sFP16 / BF164,09658 tok/s
GeForce RTX 409024 GB1008 GB/sQ8_04,09656 tok/s
Radeon RX 7900 XTX24 GB960 GB/sQ8_04,09654 tok/s
GeForce RTX 309024 GB936 GB/sQ8_04,09652 tok/s
Apple M4 (24GB)24 GB120 GB/sQ8_04,0967 tok/s
GeForce RTX 508016 GB960 GB/sQ6_K4,09666 tok/s
GeForce RTX 5070 Ti16 GB896 GB/sQ6_K4,09661 tok/s
GeForce RTX 4080 SUPER16 GB736 GB/sQ6_K4,09650 tok/s
GeForce RTX 4070 Ti SUPER16 GB672 GB/sQ6_K4,09646 tok/s
GeForce RTX 4060 Ti 16GB16 GB288 GB/sQ6_K4,09620 tok/s
GeForce RTX 3060 12GB12 GB360 GB/sQ4_K_M4,09631 tok/s
Jetson Orin Nano Super (8GB)8 GB102 GB/sno fit

Questions about this model

How much VRAM does OLMo 2 13B Instruct need?

25.5 GiB for the weights at FP16 and 7.8 GiB at Q4_K_M, from an exact count of 13,716,198,400 parameters. On top of that, the KV cache costs 800.0 KiB per token of context — 6.3 GiB at 8k and 25.0 GiB at 32k.

What is the smallest GPU that runs OLMo 2 13B Instruct?

Of the 22 accelerators here, the smallest that holds Q4_K_M weights is the GeForce RTX 3060 12GB at 12 GB — 7.8 GiB of weights against 11.0 GiB usable, leaving room for 4k tokens. For unquantized weights you need at least a GeForce RTX 5090.

Why is the KV cache for OLMo 2 13B Instruct the size it is?

Because it stores one key and one value vector per token, per layer: 40 layers × 40 KV heads × 128 dimensions × 2 (K and V) × 2 bytes = 800.0 KiB per token. This model uses full multi-head attention, so every attention head keeps its own K and V — the cache is as large as the architecture allows. None of this can be read off the parameter count.

Compare with

Method and limits. The parameter count and every architecture figure on this page are read from the model's own published config and the Hub's index over its tensor shapes, fetched 2026-08-07 — nothing here is recalled from a model's name. Weight bytes are the size of a real published file wherever one exists and the parameter count times the published llama.cpp bits-per-weight where it does not; every row says which. Speed figures are roofline bounds — memory bandwidth divided by bytes read per token — not benchmarks. Nothing on this page is written by a language model.