Very long generation with base flux_dev

[aearone]

3060ti 8 gb vram + 32 gb ram, generation time of 768x768 with flux1-dev-bnb-nf4-v2 model and 20 steps takes about 40 seconds, and with 30 steps - 1 minute 10 seconds. If I try to load the full flux1-dev model on 24 GB + ae.vae + clip_l + t5xxl_fp16 then I get a very, very long generation time, from 10 minutes (About 4-5 minutes of background preparation and another 4-5 minutes of generation. And this is at a fairly low generation resolution of 768x768) and sometimes it may not start at all, switching to eternal loading or get error for the vram (or black screen). What could be the reason?