Someone explain QPI and how it affects Overclocking please

[xthekidx]

I have an Asus P6T (non-deluxe) and i7 920 and I want to overclock it. My system currently has 3gb corsair xms3 1333, but I will be upgrading to mushkins or OCZ 1600mhz, haven't decided which yet.

I am doing my homework to try figuring out what all I should be doing, but I am confused about the QPI and how it will affect overclocking, and what I need to do to it if I am overclocking

I probably won't go higher than 3.6ghz

Thanks for the help

 

[cjl]

It's actually not that far off of the old system. The bclk is the main system reference clock, against which everything else (such as RAM speed, QPI speed, and CPU core speed) is controlled. The core has a multiplier based off of this (20x in the case of the 920), and this multiplier is locked on the non-extreme CPUs. The way to overclock is to bump this bclk up, just like the FSB on the old system. From 133, if you bump it to 180, that should give 3.6 GHz. Make sure the RAM doesn't go too high and make sure the QPI and uncore aren't set too high, or else it won't be stable. That's really all you need to know that's different - just play around a bit, keep the voltages at a safe level, and you should be set.

 

[xthekidx]

So I shouldn't worry about changing anything with the QPI when I overclock, except the uncore voltage?

I have heard some people say that increasing the QPI also results in a light OC of the CPU...how does that work? How does QPI speed differ from ram speed? Since the QPI is the memory controller, shouldn't overclocking the ram go hand-in-hand with overclocking the QPI?

 

[cjl]

QPI isn't the memory controller - it is the connection from the CPU to the northbridge. The memory controller is completely separate.

 

[xthekidx]

ahh ok. thanks cjl