Always overclocked my 2600k setting turbo mode to off and increasing the muliplier to 45x......but would it be different if i stayed on the stock multiplier 34x and increased the turbo clocks to 45 instead of ( Auto/OFF ) on each core ?
When you overclock via the multiplier and have the turbo boost off.. You're at that multiplier at all times unless you have speedstep enabled which allows the OS to drop the multiplier at idle to save power. So when you start using the processor it's still at the selected multiplier.
Now running turbo multipliers with a stock multiplier works a little different.
When you reach a threshold (not sure how it works) the processor will clock itself to the turbo multiplier. However this isn't always consistent and can actually be difficult to manage correctly; especially with voltage concerns.
Now, stock on the 2600k goes like this
Stock 4 cores at 3.4Ghz
Turbo 1 : 4 cores at 3.5Ghz
Turbo 2 : 3 cores at 3.6Ghz
Turbo 3 : 2 cores at 3.7Ghz
Turbo 4 : 1 cores at 3.8Ghz
So, basically you'd have to tune the multipliers the way you want. To get an effective clocking you'd have to set the four cores to your overclock to achieve the same performance and also run through the additional turbo voltage to keep it stable if you're running a normal voltage.