Is accessing memcached bucket slower than direct memory array read/write?

I have a nodejs project needs to store/read temporary data.
Somebody suggest me use memcached bucket.
As I know couchbase server always separate from application server.
Just wonder if memcached bucket is in another physical server, nodejs app access memcached bucket via socket is slower than direct memory array/list access(even they are in same local network) ?
Most cases, the socket delay can be neglected, but for high speed real-time game, I think it will be huge.

Your comment welcome