I ripped my collection of 400CD's last Christmas and it took a couple of months in between having a life. I used DBpoweramp and a laptop which took on average 6-8mins to rip a disc to FLAC. A dedicated drive would have been faster but I was already fiscally challenged from the outlay of the Sonos, NAS combo and subsequent USB harddisk for a further backup.
Start with the most recent and most played stuff so you can start enjoying the benefits right away.
Paul
Onkyo 875, Monitor Audio RX6 GW,Monitor audio RX centre GW,Monitor Audio BFX rears, REL QUAKE,Arcam CD73t CD ,Russ Andrews Yello mains cabling & PBJ interconnects,Sterling Black Mamba speaker cable.