Hi, i have a TeraStation PRO TS-HTGL/R5 and a 1.5TB external USB drive that is connected to it. I started a backup yestertay and its still only at 20%. Even though its about 1,1 TB of data that has to be backuped this seems awfully slow to me. Is this normal? The external USB drive is a Verbatim, so it should support speeds bigger than this.