Best GPU for local AI

Which AI models can the L40 / L40S run?

The L40 / L40S has 48 GB of graphics memory, read at 864 GB/s. In a workstation with 256 GB of DDR5-6400 in eight channels, 57 of the 88 open models here run entirely on the card, 56 of them writing faster than you read; the most capable it runs well is Qwen2.5 72B at Q4_K_M, 10–17 tokens/s. 28 more run with part of the model in system memory, more slowly.

Every figure is for an 8,192-token conversation (about 6,000 words), at the best compression that fits. Try it in the calculator with your own memory, conversation length and compression, or a second card. For image and video models, see Stable Diffusion, FLUX and Wan on the L40 / L40S.

Models that run entirely on the card

The fastest way to run a model: all of it in graphics memory. Most people read at 5 to 8 tokens a second, so anything above 10 feels quick.

Models the L40 / L40S runs entirely on the card
ModelCompressionWritesNeeds
Mistral Medium 3.5 128BIQ2_XXS13–21 tokens/s38 GB
Qwen3 Coder Next 80B-A3BQ3_K_M150–240 tokens/s39 GB
Nemotron 3.5 Bolt 74B-A9BQ4_K_M67–105 tokens/s45 GB
Qwen2.5 72BQ4_K_M10–17 tokens/s47 GB
Llama 3.3 70BQ4_K_M11–17 tokens/s45 GB
Flint 40B-A2.5BQ8_0105–170 tokens/s43 GB
Qwen3.6 35B-A3BQ8_097–155 tokens/s38 GB
Qwen3 32BQ8_013–21 tokens/s37 GB
Nemotron 3.5 Lightning 30B-A3BQ8_098–155 tokens/s34 GB
Gemma 4 31BQ8_014–22 tokens/s34 GB
GLM-4.7 FlashQ8_095–150 tokens/s34 GB
Qwen3 30B-A3B 2507Q8_086–140 tokens/s33 GB
Qwen3 Coder 30B-A3BQ8_086–140 tokens/s33 GB
Muse Glimmer 30BQ8_015–24 tokens/s32 GB
Granite 4.2 30BQ8_015–24 tokens/s33 GB
Qwen3.6 27BQ8_016–25 tokens/s30 GB
Qwen3.8 27BQ8_016–25 tokens/s30 GB
Gemma 3 27BQ8_016–25 tokens/s30 GB
Gemma 4 26B-A4BQ8_081–130 tokens/s28 GB
Mistral Small 3.2 24BQ8_018–29 tokens/s27 GB
Devstral Small 2 24BQ8_018–29 tokens/s27 GB
LFM2.5 24B-A2BQ8_0110–175 tokens/s26 GB
gpt-oss 20BMXFP4125–200 tokens/s12 GB
Qwen3 14BQ8_029–46 tokens/s17 GB
Phi-4Q8_029–46 tokens/s17 GB
Ministral 3 14BQ8_030–48 tokens/s16 GB
Gemma 3 12BQ8_034–55 tokens/s14 GB
Gemma 4 12BQ8_036–57 tokens/s13 GB
Qwen3.5 9BQ8_044–71 tokens/s11 GB
Ornith 1.5 9BQ8_044–71 tokens/s11 GB
Ministral 3 8BQ8_046–73 tokens/s11 GB
Granite 4.2 8BQ8_046–74 tokens/s11 GB
Qwen3 8BQ8_049–79 tokens/s9.9 GB
DeepSeek R1 0528 Qwen3 8BQ8_049–79 tokens/s9.9 GB
Llama 3.1 8BQ8_051–81 tokens/s9.6 GB
Gemma 4 E4BQ8_091–145 tokens/s8.7 GB
Qwen2.5 7BQ8_055–88 tokens/s8.6 GB
Mistral 7B v0.3Q8_056–89 tokens/s8.8 GB
Gemma 4 E2BQ8_0170–270 tokens/s5.5 GB
Qwen3.5 4BQ8_088–140 tokens/s5.2 GB
Gemma 3 4BQ8_093–150 tokens/s4.9 GB
Qwen3 4B 2507Q8_091–145 tokens/s5.5 GB
Ministral 3 3BQ8_098–155 tokens/s5.0 GB
Phi-4-miniQ8_096–155 tokens/s5.2 GB
Granite 4.2 3BQ8_0105–165 tokens/s4.6 GB
Llama 3.2 3BQ8_0110–180 tokens/s4.4 GB
SmolLM3 3BQ8_0120–195 tokens/s3.9 GB
Qwen3.5 2BQ8_0170–270 tokens/s2.5 GB
Qwen3 1.7BQ8_0160–255 tokens/s3.1 GB
LFM3 1.7BQ8_0210–335 tokens/s1.9 GB
Llama 3.2 1BQ8_0260–420 tokens/s1.6 GB
Gemma 3 1BQ8_0325–520 tokens/s1.1 GB
Qwen3.5 0.8BQ8_0355–565 tokens/s1.0 GB
Qwen3 0.6BQ8_0290–465 tokens/s1.7 GB
SmolLM2 360MQ8_0515–820 tokens/s0.7 GB
LFM2.5 350MQ8_0595–950 tokens/s0.5 GB
Gemma 3 270MQ8_0695–1110 tokens/s0.3 GB

With help from system memory

In a workstation with 256 GB of DDR5-6400 in eight channels, these fit with part of the model in system memory. The processor reads that part several times more slowly, so they write more slowly the more of them is off the card.

Models the L40 / L40S runs with part in system memory
ModelOn the cardWritesNeeds
Kimi K2.623%8.7–14 tokens/s206 GB
Mistral Large 4 1T-A52B17%3.8–6.1 tokens/s276 GB
Inkling 975B-A41B17%4.8–7.7 tokens/s269 GB
Muse Spark Open 816B-A42B21%4.7–7.6 tokens/s227 GB
DeepSeek V4.1 Flash16%9.1–15 tokens/s286 GB
GLM-5.3 753B17%2.9–4.7 tokens/s283 GB
DeepSeek V3.234%8.7–14 tokens/s138 GB
DeepSeek R1 052834%8.7–14 tokens/s137 GB
Qwen3 Coder 480B-A35B48%10–16 tokens/s98 GB
MiniMax M3.1 Flash 428B-A23B39%10–17 tokens/s119 GB
Llama 3.1 405B19%0.23–0.37 tokens/s250 GB
Qwen3.5 397B-A17B31%9.9–16 tokens/s152 GB
Llama 4 Maverick 400B-A17B31%9.0–14 tokens/s152 GB
GLM-4.7 355B-A32B46%7.7–12 tokens/s102 GB
GLM-5.3 Flash 320B-A18B39%10–17 tokens/s121 GB
MiMo V2.6 Flash 309B-A15B31%8.7–14 tokens/s151 GB
Hy3 295B-A21B41%8.1–13 tokens/s113 GB
Inkling Small 276B-A12B28%8.3–13 tokens/s168 GB
Qwen3 235B-A22B 250752%9.7–15 tokens/s90 GB
MiniMax M2.7 230B-A10B33%9.3–15 tokens/s141 GB
Step 3.5 Flash39%10–16 tokens/s120 GB
Qwen3.8 Flash Next43%19–31 tokens/s109 GB
Qwen3.5 122B-A10B62%16–26 tokens/s76 GB
Nemotron 3.5 Super 120B-A12B62%14–23 tokens/s76 GB
Mistral Small 4 119B64%26–41 tokens/s73 GB
gpt-oss 120B73%41–66 tokens/s64 GB
GLM-4.5 Air 106B-A12B68%15–24 tokens/s69 GB
Llama 4 Scout 109B-A17B69%11–18 tokens/s67 GB

The other 3 need more memory than a workstation with 256 GB of DDR5-6400 in eight channels has; the calculator shows what more memory, or a second card, would add.

Two L40 / L40Ss

Two of them pool 96 GB, enough for 64 of the models entirely on the cards, 7 more than one holds. The most capable that runs well is Qwen2.5 72B at Q6_K, 7.8–12 tokens/s. A second card adds memory, not speed: a model that already fits on one runs no faster on two.

Compared with similar graphics

Tokens per second writing Llama 3.1 8B at 4 bits, which every 8 GB card holds, and the most capable model each runs well on its own. Every card ranked.

GraphicsMemoryLlama 3.1 8BMost capable it runs well
RTX 309024 GB115Qwen3 32B
Instinct MI21064 GB115Qwen2.5 72B
RTX 3080 Ti12 GB110Qwen3 14B
L40 / L40S48 GB110Qwen2.5 72B
RTX 3080 12 GB12 GB110Qwen3 14B
RTX 4080 SUPER16 GB110Qwen3 14B
Radeon AI PRO R970032 GB105Qwen3 32B

Estimated tokens per second; a real figure is usually within a quarter either way. * Part of it in system memory. {CAPABLE_NOTE}

How it is worked out

Writing an answer is limited by memory rather than arithmetic: for every word-piece (token) a model writes, the computer reads every weight that token uses once. So the speed is how fast the memory holding the model can be read, divided by how much is read for each token: the model’s weights at the chosen compression, plus the conversation so far. How much of its memory speed each graphics card reaches is measured, not assumed: it comes from the card’s own result in llama.cpp’s benchmark, which LM Studio, Ollama and Jan are built on. A model that does not fit in the graphics card’s memory spills into system memory, five to fifteen times slower, and one that does not fit in memory at all can be read from the drive as it runs, slower again; the estimate counts each part at its own speed, and a processor with few threads cannot use all of fast memory. Graphics built into a processor use system memory, at its speed. Reading a prompt is limited by arithmetic, so it follows the measured prompt speed.

Already running a model? See if it runs at full speed

A model that is slower than it should be is nearly always partly on the processor rather than all on the graphics card, which is several times slower — and Ollama does that without a word when something else holds the card’s memory. Bottleneck’s free app checks a model run with Ollama, LM Studio, llama.cpp, KoboldCpp or Jan: where it really runs, how fast it writes, and what your PC should manage with it. Nothing leaves your PC. Or check and fix it by hand.

It reads your parts too: the graphics card and how much memory it really has free, how much system memory is installed, the speed it runs at and in how many channels. Memory left in one channel, or below its rated speed, halves how fast a model runs from it, and Bottleneck says so. Its AI models screen then lists what runs on this PC.

The free version shows where a model runs and how fast, with no time limit and no account. Pro, $9 once, explains why it is slower than it could be and how to fix it. Compare the versions