CABLING
44 of the signal , the more that the electrons move to the outside of the cable , and then end up radiating into space ,” explains Smith “ At slow speeds you can go a long distance , which means that older , smaller data centres can use copper without any problems .” In larger enterprise , colocation and hyperscale facilities , however , copper cabling struggles to perform over the long distances between racks , especially as the IT load these cables are expected to handle increases year over year .
“ A one gig copper cable could go maybe 500 metres . A 10Gb cable could go maybe 100 metres , but things start to fall apart when you get up to 25 Gb ,” Smith explains . “ The power usage , cost , you name it - it all just gets very ugly . So the industry moved to using direct attach copper ( DAC ) cables , which use a foil shield to extend the range and capacity of copper cabling . However , once you get up to 100Gb capacity , the range of these cables is only about a metre .”
In an enterprise facility with thousands of square metres of floor space , the limitations become clear . “ If you ’ re
DECEMBER 2020