[Skie]

I've actually seen various things over the years that state Cat5 is only really reliable with Gige at 10m lengths. Cheap Cat5 was pretty common too and was utter pants, back in the days when speeds over 100mbps were still theoretical or reserved for large corporations consumer stuff was never really manufactured to a decent standard.

There shouldn't be much cheap Cat5 left though, 5e replaced it long ago and as others have said Cat 6 is standard now.