With my system, Llama.cpp can run Mistral 7B 8-bit quantized by offloading 32 layers to the GPU (35 total) at about 25-30 tokens/second, or 6-bit quantized by offloading all layers to the GPU at ~ 35 tokens/second.
I've tested a few 13B 4-bit models such as Codellama and got about 10 tokens/second by offloading 37 layers to the GPU. Got me about 10-15 tokens/second.
It's also possible to run on CPU from system RAM, to split the workload across GPU and CPU, or even from a memory-mapped file on disk. Some people have posted benchmarks online [1] and naturally, the faster your RAM and CPU the better.
My personal experience is running from CPU/system ram is painfully slow. But that's partly because I only experimented with models that were too big to fit on my GPU, so part of the slowness is due to their large size.
[1] https://www.reddit.com/r/LocalLLaMA/comments/14ilo0t/extensi...
Tried turning on mlock and upping thread count to 6, but it's still rather slow at around 3 tokens / sec.