no gpu for 70B model

llama/llama.go

@@ -128,6 +128,11 @@ func New(model string, opts api.Options) (*LLM, error) {
 
 	C.llama_backend_init(C.bool(llm.UseNUMA))
 
+	// TODO: GQA == 8 suggests 70B model which doesn't support metal
+	if llm.NumGQA == 8 {
+		llm.NumGPU = 0
+	}
+
 	params := C.llama_context_default_params()
 	params.seed = C.uint(llm.Seed)
 	params.n_ctx = C.int(llm.NumCtx)