I just purchased a 3TB WD My Cloud Personal Storage External harddrive and after connecting it to my network and upgrading the firmware I started my first backup ( wirelessly ) of my MacBook Pro using the " Time Machine " application as outlined in the manual . I started the upload to MyCloud yesterday and it shows a total of 96.86 GB to be upload during the backup . So far over night it has backed up 37.90 GB of the total . I am on DSL network . Is this about normal to backup a computer the first time ?? —I’m guessing at this rate it will be another day or so before the backup is complete.
Depends almost enterely on your LAN devices speeds:
Router and/or computer at 10/100 SLOOOOW to eternal.
Router AND computer Wifi b/g SLOOOOW to eternal.
Router AND computer Wifi N SLOOOOW to eternal.
Router AND Wifi AC NORMAL.
Router AND computer at 1Gb NORMAL.
If you have $$$:
Router AND computer at 10GE the limit is the MyCloud.
P.S: Of course if source is attached to USB 2 it will slow all your transfers process…Use USB 3 case for external or even esata.
Dont do timemachine over wifi unless you have AC.
How do I do the backup then ?
Don’t know what you mean by AC ?? ---- WD storage device is connected to AC and laptop is connected to AC . Is that what you are refering to ?
IEEE 802.11ac is a wireless computer networking standard in the 802.11 family (which is marketed under the brand name Wi-Fi), developed in the IEEE Standards Association process,  providing high-throughput wireless local area networks (WLANs) on the 5 GHz band.  The standard was developed from 2011 through 2013, with final publication by yearend, 2013.  According to a study, devices with the 802.11ac specification are expected to be common by 2015 with an estimated one billion spread around the world. 
This specification has expected multi-station WLAN throughput of at least 1 gigabit per second and a single link throughput of at least 500 megabits per second (500 Mbit/s). This is accomplished by extending the air interface concepts embraced by 802.11n: wider RF bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256-QAM). 
Wireless AC. Most likely you don’t have it, so plug the mac into the router / switch first, turn off wifi on the mac, and run timemachine.
The router is connected via the Ethernet cable, but if the remote computer is wireless it will be slow as said.
Typical wi-fi speeds are 2MB/second to 7MB/second so a 100GB file would take almost SIX HOURS at 5MB/second.
My WRITE SPEEDS to the box were about 50MB/second average, or faster than most USB hard drives.
The MYCLOUD is really fast (up to 80MB/second read) but it is limited by your network so you need a Gigabit router with the PC connected via Ethernet for fast access.