i5/i7 CPU & memory multiplier noob questions

[IanM]

I'm trying to wrap my head around the basics as I'm trying to figure out which CPU & memory to go for.

LGA 1156 uses a base clock of 133.333...Mhz, i5 750 has a bus/core multiplier of 20 so is 2.66Ghz. Is the bus/core multiplier strictly locked at 20, or can it be reduced? i.e. can I configure the system as:

raise the base clock to 166.666...Mhz

+

use bus/core multiplier of 16 for CPU to remain at 2.66Ghz

+

memory at PC3-16000 (2000Mhz)​

This is quite a contrived example, so as an OC it may look a little pointless, but that leads me to my second question: would doing something similar to the above be good for running a quiet system with stock CPU speed some of the time, but leave plenty of headroom to to use Turbo mode while gaming?

 

[tinytomlogan]

You couldnt change the BCLK like that without overvolting I doubt. Its not as simple as keeping the end GHZ result the same. Plus the mem is linked to the BCLK also by a multi.

 

[IanM]

mem is linked to the BCLK also by a multi.

I assumed this was adjustable in the BIOS? or is the RAM multiplier always fixed?

I was looking at the latest Asus P7P55D-E Pro/Evo/Deluxe motherboards and the spec sheets say RAM up to 2200Mhz is supported so I had hoped it would be relatively straightforward to set up.

You couldnt change the BCLK like that without overvolting I doubt.

Obviously I'm quite ignorant about this, so overvolting where? CPU & integrated memory controller + everything else affected by BCLK, or just the components integrated on the motherboard?

 

[PP Mguire]

Actually yes you CAN do that. You can leave the core v at stock too. For example, if you get 2000mhz XMP ram it does exactly like your saying. Not only that, but if you turn on speedstep and turbo it raises the multi to 21 and when you have a higher demand task will slightly OC your cpu.

To put bsclk in simple, it is simply FSB if your used to that term from older machines. You raise your FSB you raise everything correct? Well in this case you need to raise your FSB to achieve your 2000mhz ram clock but just lower your cpu multi to achieve stock speed or if you wish a slightly overclocked cpu. Or if your cool and have a really good CPU cooler and airflow you can 1:1 your ram with cpu and have a 4.0ghz cpu and 2000mhz ram. Btw bsclk would have to be 200 to achieve 2000mhz ram.