Overcloking Haswell cores coming from Intel Core 2

[funkadikto]

Hi guys.

I´m looking for information about overclocking Haswell K Cores. Last PC I bought had an Intel Core 2 Duo Wolfdale and, from the overclocking perspective, it was all about incrementing the FSB (front side bus) speed and having it sync 1:1 to the DDR SDRam speed. The core multiplier was really a secondary thing. It was better to have a CPU clock speed of 333 Mhz and lower multiplier than a CPU clock speed of 266 and higher multiplier because the point in those days was trying to bypass the FSB bottleneck in terms of performance.

Looking now at Haswell K core overcloking, everybody talks about incrementing the core multiplier, but the CPU Clock speed has disappeared from the equation. By the way, I can only think that a CPU clock speed of 100 Mhz is incredible low compare to the 400 Mhz clock speed that older Intel Core 2 Duo and Quad processors could achieve.

Can you give any clues? Isn´t the Clock Speed in Haswell K cores important in terms of performance?

 

[NiCoM]

I have the i5-4670K from Haswell and I've tried increasing both by themselves.

The standard multiplier increasement will give you a good boost in performance, it's the way that probably 99% overclock on Haswell.

Then some day i wanted to see what a change in the CPU speed would do for me, i lowered the multiplier to the stock settings, and then raised the CPU clock 100Mhz->125Mhz. Now my pc didn't work properly at all, it wouldn't even boot into bios anymore. I had a lot of hassle making it work again.

So I'm pretty sure you should just increase the multiplier and the voltage. This will give you a very nice performance boost. Think a multiplier of 44 is something most i7's and i5's from Haswell will be able to reach (K-series of cource). If you get a very badly binned i7-4770K, it might be that you only want to go to 43 or 42.

Hope this helped!

EDIT: i mean CPU Strap not CPU clock x)

 

[jaguarskx]

FSB no longer exists for Intel CPUs. It has been changed to BCLK.

FSB allowed you to simply increase the clock speed of the CPU and the RAM.

BCLK basically controls most of the device frequencies on the motherboard. That includes the PCI-e slots and USB slot. It is generally not recommended you increase the BCLK because even increasing the BCLK to 110MHz have permanently damaged USB ports according to some people. It has been a while, but I think the maximum recommended BLCK is 107MHz since going higher than that can prevent the PC from booting up or cause permanent damage.