How long to stress test for overclocking?

Currently overclocking my FX-8350 and have found that it isn't able to get above 4.6 Ghz without throwing errors or having to have enough volts shoved through it to burn the entire town to the ground.
I'm just wondering how long I should test it for? 12 hours pegged at 100% seems OTT because I'm never going to push it that hard. Going strong so far even though I'm only 45 mins in, temps stable and no errors in OCCT so far.

 

2hrs shortest preferably overnight did that with undervolting my laptop and it failed 3hrs in!

 

Chuckle* It is recommended that you maintain cooling over your voltage regulation modules usually located near the I/O ports of your motherboard. These chips do get a we bit toasty don't they. Many people use their stock cpu heatsync fan placed with zip ties to keep air circulating around the socket. I used a memory cooler fan pair for awhile. Ever since upgrading my case to be more quiet it has gotten quite warm but still quite fun to play with.

Perhaps stop over to the Folding Lounge and crunch some numbers with us BEAMNG started by Bubbleawesome http://www.beamng.com/threads/701-BeamNG-s-Folding-Home-Lounge-Team-224614
That is probably the best way to keep your overclock extra warm for testing. Summer is coming, oh sh*t.