I5 750 Dynamic Overclock

[mognet]

I was trying to get my i5 to run in a simlar way to the tom's efficiency article, where they had a base 3.2 Ghz (160x20), with all the turbo and idle power saving settings still running. At the moment my CPU idles at 160 x 9 but when its loaded it goes to 21x even with all 4 cores loaded in prime95. I can also never get it to run the higher multiplier even if i only apply 1 or 2 threads.

My motherboard is ASUS P7P55D-E LX Intel P55 Core i7/i5/i3 PCI-E DDR3 LGA1156 SATA3+USB3 ATX

 

[wolfram23]

My guess is it is actually going higher. What were you monitoring with? CPUZ? Because it's not always accurate at changing it. Same with many other monitoring programs. IMO, download the Turbo Boost gadget which shows realtime what your CPU speed is running at.
http://techreport.com/discussions.x/18124

 

[mognet]

I am using CPU-Z, the link you posted says the item is no longer available from Intel

 

[mognet]

Sorry for the double reply, I found another link i guess the one linked in the article was broken.

Using that tool i see the same thing: 1,2,3,4 threads all get boosted to 21x160

 

[wolfram23]

Does it work if you revert to default settings?

 

[mognet]

I realised I have c-states disabled will this affect thing. I haven't been able to get my system to boot with c-states on.

I have been playing around a bit more with my BCLK and now have it at 170 clocking up to close to 3.6 under load, seems to go up to x21 even on all 4 cores and still down to x9 when unloaded which I am pretty happy with. Do you think there is much to be gained trying to get it running with the higher turbo?

Still all running stock voltage

 

[wolfram23]

C States are the issue then, they have to be on for Turbo to work...

There's no way to get 170 base clock at stock volts with turbo on. If you want turbo you'll have to either lower the clock or add voltage. IMO turbo is really good and highly efficient since not many things are well multithreaded so the performance will generally be better.

 

[mognet]

I wasn't able to boot at 160 with c-states enabled do you have a suggestion for starting voltage to test from?

Also my ram is running at 1T if that makes a difference. I had a look but i can't even see where that setting is in my BIOS

 

[wolfram23]

Honestly it should work at auto, but make sure the RAM is set to the right timings and voltage (probalby 1.65V, 8-8-8-24 timings). 1T and 2T do make a small diffence in RAM stability but overall not a big difference on overall RAM speed.

But for voltages, IMO it should boot at 1.27 Vcore and 1.17 VTT or thereabouts. Maybe even a bit lower. Make sure Load Line Calibration is on.

 

[mognet]

There was only one V setting available in my BIOS so i set that to just shy of 1.27 V and it was able to boot with all those setting enabled. I get 3.84 with 1 prime thread and 3.36 with 2-4 loaded yay!

Will be doing a bit more testing to see how much i can push it or drop the voltage

 

[wolfram23]

You should definitely have a VTT voltage... might be listed as IMC?

 

[mognet]

It was indeed listed as IMC, set to 1.18 since it went in steps of 0.02

 

[mognet]

Currently running at
165 BCLK
1.24 Vcore

Seems stable in short runs of Prime95 and turbo is kicking and multiplier moves between 21 and 24 loaded and drops back to 9 at idle.

Thanks for all your help Wolfram

 

[wolfram23]

Great, hopefully the temps are good too

Glad I could help.

 

[mognet]

Idles are high 20s/low 30s depending how warm i have my room. Full load they nudge over 50.