As has been mentioned above, depends what you want to do with the signal, dunnit? In a similar vein, the VGA specification suggests that 5m is the maximum, yet I'm running a projector 25m away from the computer*. Very little degradation of picture,
except on the occasion when some bright spark decided it would be neater to bundle the cable with the hearing loop.
He has been spoken to.
*Just remembered - 'tis a 10m and a 15m cable joined together with an f-f connector: even worse.