Multi GPU support

[gotyer]

With multiple GPUs, we see "FULL GPU OFFLOAD POSSIBLE" for a lot of models, but when trying to load them, it crashes and gives a memory error.

Please either implement multi GPU offload, or correct your memory calculation, as to not mislead the user.

For now, I will have to use ollama as they support multi GPU offload, but I would rather continue using LM studio for conveniency.

---

GPUs : 2x RTX 3090 (24Go each)
Model : meta-llama/Meta-Llama-3.1-70B-Instruct (IQ3_M, 34.27 GB)

---

full error:

{
"memory": {
"ram_capacity": "63.90 GB",
"ram_unused": "51.85 GB"
},
"gpu": {
"gpu_names": [
"NVIDIA GeForce RTX 3090",
"NVIDIA GeForce RTX 3090"
],
"vram_recommended_capacity": "48.00 GB",
"vram_unused": "45.55 GB"
},
"os": {
"platform": "win32",
"version": "10.0.22631"
},
"app": {
"version": "0.2.31",
"downloadsDir": "---\lm-studio\models"
},
"model": {}
}