Dual 12GB GPUs Face LM Studio Tradeoff

The 5070 is the better single-card upgrade, but the second 12GB card only helps if you actually need more aggregate VRAM or multiple concurrent loads.

• –NVIDIA’s specs put the RTX 5070 at 12GB GDDR7 with far more compute than the RTX 3060’s 12GB GDDR6, so raw throughput should favor the newer card by a wide margin.
• –LM Studio now exposes multi-GPU controls on CUDA, including GPU ordering and per-GPU enable/disable, so dual-card setups are supported but not entirely plug and play.
• –The 24GB pool is most valuable for fitting larger models or keeping more context resident; it does not automatically double speed, and splitting work across a weak plus strong GPU can leave performance uneven.
• –If the goal is simple, fast inference, one 5070 is cleaner. If the goal is maximum model size on a budget, dual 12GB cards can be pragmatic, but only if the motherboard, power, cooling, and software setup are ready for it.