Performance of a singleton instance OkHttpClient

Question

I'm using OkHttp at the first time. I see the tutorial said that If wanna use Response Caching, I must call new OkHttpClient() exactly once (a singleton instance). OkhttpClient is thread-safe by synchronized methods. But in my application, there are many threads connects to the network to get remote data simultaneously, some threads must wait for a thread have done getting data to execute its operation.
So Is it's performance not better than normal?
If yes, If I don't enable Reponse Caching, should I call new OkHttpClient() many times for better performance?
Thanks

Answer 1

For the best performance, share a single OkHttpClient instance. This allows your cache to be shared, and in the future when we implement fancy joining & cancelling it’ll allow outgoing requests to be merged.