How long for prime 95 testing (4 stable oc)

[windheaven]

Testing my i5 2500k, 4.5 @ 1.308v it's done just over 4 hours as i currently type this under blend testing.

How many hours would suffice to determine weather the clocks are stable or not?

ty

 

[windheaven]

last night 30 loops of IBT max ram possible, with 12 hours on prime and occt previously

i defo deem my o.c stable,..unfortunately it's at 4.4 couldn't manage 4.5 oh well..