UberInferno

you wont help anything by downclocking your gpu, as it does by itself when its not as much in use.
all i'd advise you to do is reduce the fan if you're looking for some silence, 80 degrees should be fine

Actually - It's not guaranteed.
That's why I referred to the version/revision of a stick.
 
With that said I suspect the IC's are different and would act differently too if you OC them but it's definitely possible to run them together at their rated stock speed.

It depends on how the manufacturer programmed XMP profiles into the sticks. They differ from make to make and model, that includes the IC's used in the sticks and yes even if the make and model are the same it can depend on the version/revision of the sticks too, that being an indiator of what IC's the sticks would have.
While it is possible, for the most part I'd have to say your chances of finding sticks that are of different makes/models using the same XMP profile isn't that good.
 
Would be best to have them all the same right down to the version/revision so the IC's and XMP profile programming matches between all sticks in use.
 

Really nothing to lose by going for it.
I did my 3770K sometime ago and it did helps temps under load.

cba bout risk, everything i've done to this pc had risk involved.
rust is the game that seeps ram and cpu as much as it can.
i'm doin this anyway

It might be limited to 3.9 on all 4 cores, turboing up to 4.2 on a single core.  That would be in line with my own i5-2500 which (on a Z77 board) does 3.8 on all 4 cores and 4.1 in single core loads. 
 
Perhaps you could push it to do 4.2 on all cores by turning off Turbo and/or Speedstep?  I honestly didn't dig too deep into the overclocking options of mine, I merely turned up the multiplier (to x41) and called it a day.

The i7-2600 will indeed go to 4.2 on stock voltage.  As for overclocking on P67 motherboards, I only have experience with the Gigabyte P67A-UD3 and had no issues overclocking on that one.

for the corsair ram, you see yourself, Samsung ram i checked via serial code, and found that its cl11 1600mhz

Mixing RAM makes them run at their default timings and speed

No unless it's rated at stock speeds only which I doubt