Can an RTX 4090 run LFM2.5-24B-A2B?
Yes: an RTX 4090 runs LFM2.5 24B-A2B at 231.9 tok/s at Q4_K_M, measured on llama.cpp with a 114-token prompt in October 2026.
1 signed run on llm-speed. Single-request decode speed in tokens per second; the short-chat workload unless noted. This run was measured by llm-speed (@llmspeed). Runs measured by llm-speed are credited to @llmspeed.
Measured tok/s by quant and runtime
| Quant | Runtime | Build | Decode tok/s (best run) | Workload | Runs | Source |
|---|---|---|---|---|---|---|
| Q4_K_M | llama.cpp | commit a0e6dc7 | 231.9 | chat-short | 1 | Measured by llm-speed@llmspeed |
Fastest quant that fits: Q4_K_M on llama.cpp, 231.9 tok/s (measured by llm-speed; it fits because it ran on this hardware). Quants without a run are not listed.
Every measured row
| Run | Date (UTC) | Workload | Quant | Runtime / build | Prompt tokens | Output tokens | Decode tok/s | Prefill tok/s | TTFT ms | VRAM GiB | Source |
|---|---|---|---|---|---|---|---|---|---|---|---|
| r_bqmpv9kncyd | 2026-10-15 | chat-short | Q4_K_M | llama.cpp · commit a0e6dc7 | 114 | 256 | 231.9 | 640.1 | 178 | – | Measured by llm-speed@llmspeed |
| r_bqmpv9kncyd | 2026-10-15 | chat-long | Q4_K_M | llama.cpp · commit a0e6dc7 | 3284 | 1024 | 233.4 | 9512.4 | 345 | – | Measured by llm-speed@llmspeed |
| r_bqmpv9kncyd | 2026-10-15 | agent-trace | Q4_K_M | llama.cpp · commit a0e6dc7 | 3514 | 840 | 231.0 | 13801.7 | 153 | – | Measured by llm-speed@llmspeed |
| r_bqmpv9kncyd | 2026-10-15 | concurrent-decode | Q4_K_M | llama.cpp · commit a0e6dc7 | 1024 | 256 | 236.8 | – | – | – | Measured by llm-speed@llmspeed |
Questions
Can an RTX 4090 run LFM2.5-24B-A2B?
Yes: an RTX 4090 runs LFM2.5 24B-A2B at 231.9 tok/s at Q4_K_M, measured on llama.cpp with a 114-token prompt in October 2026.
How many tokens per second does LFM2.5-24B-A2B get on an RTX 4090?
Decode speed measured by llm-speed, by quantization and runtime: Q4_K_M on llama.cpp: 231.9 tok/s. Based on 1 run measured by llm-speed; single-request chat-short unless noted.
What is the fastest quant of LFM2.5-24B-A2B that fits on an RTX 4090?
Q4_K_M on llama.cpp was the fastest measured setting at 231.9 tok/s; it fit because it ran. Other quants are listed only where a run measured them.
How much VRAM does LFM2.5-24B-A2B use on an RTX 4090?
Memory use was not recorded for these runs. The VRAM calculator gives an estimate, not a measurement.