i5 Overclock

LEK-89 · 15 Jul 2011 at 21:11

Moving on from my RAM thread: http://forums.overclockers.co.uk/showthread.php?t=18295485 I felt that it was time to make a new thread in here.

I've now been looking into & playing with the overclocking on my new rig a bit.

I started off earlier at 4.2Ghz, CPU voltage still at set at auto, turbo boost turned off and booted back into Windows. CPU-Z reported that the CPU was running at 4190Mhz (why is it not at full whack 4200Mhz?) and the CPU voltage was running at 1.320v when idle and 1.22 - 1.30v at full load.

I was then alerted (Thanks to Plec!) that I also needed to turn on C1E in the BIOS (by default it's turned off, this also explained why SpeedStep did not kick in at all after overclocking at first) and after this, idle core voltage was at 1.000v (when SpeedStep automatically kicked in and set the CPU to 1600Mhz) and the CPU voltage was lowered to 1.264 - 1.272v during full load.

Anyway, I've just decided to give 4.4Ghz a go, here are the results. This is with C1E enabled, turbo boost turned off and speedstep turned on:

How does this look to you guys? I'm just after a bit of advice really and if their is anything from the BIOS that I may need to change? How do I go about manually changing the CPU voltage too, if I need to?

Thanks all - Liam

Phenomenologica · 15 Jul 2011 at 21:46

Your clock speed is slightly below what you set because your BCLK is at 99.8 not 100. You can afford to nudge it up if you like. Most people don't advise auto voltage for high overclocks as it can stick uncomfortable levels through the CPU, setting the voltage manually or using an offset is preferred. An offset has the benefit that it will still lower the voltage when idle. I can't advise you on the specifics as I have a Gigabyte board so am not familiar with your BIOS.

LEK-89 · 15 Jul 2011 at 22:02

Phenomenologica said:
Your clock speed is slightly below what you set because your BCLK is at 99.8 not 100. You can afford to nudge it up if you like. Most people don't advise auto voltage for high overclocks as it can stick uncomfortable levels through the CPU, setting the voltage manually or using an offset is preferred. An offset has the benefit that it will still lower the voltage when idle. I can't advise you on the specifics as I have a Gigabyte board so am not familiar with your BIOS.

I've just looked in my BIOS again with how to manually adjust the BCLK to 100 and I can't seem to find it. Maybe someone who owns an MSI GDxx motherboard could help me out?

Thanks for pointing out the BCLK to me Phenomenologica

Liam

Plec · 16 Jul 2011 at 09:42

Phenomenologica said:
An offset has the benefit that it will still lower the voltage when idle.

Unfortunately his MSI board doesn't have an offset feature - so for 'low' clocks the auto voltage is sometimes the better option (if voltages remian low under stress as the vCore will reduce to ~0.98V when idle).

LEK-89 said:
How do I go about manually changing the CPU voltage too, if I need to?

You need to go back into the overclocking screen and click on the 'CPU Core Voltage' and then select a voltage from the options available.

Your temps and voltages look good at 4.4GHz you could leave it on auto (so that voltages drop during idle) or you could experiment with 1.2+ voltages and see what you can get.

If they creep up to ~1.26v then you would be better off using auto - as you would be nearing the voltages you have now but without any of the benefits of idle voltage.

Additional: Make sure 'spread spectrum' is disabled.

LEK-89 · 16 Jul 2011 at 14:29

Ok, just had another go just now with the overclocking.

Went back into the BIOS and set everything up for a 4.4Ghz overclock, with speed spectrum disabled and after this I noticed in CPU-Z that at full what it's now dead on 4.4Ghz (Thanks Plec) and I also manually set the core voltage to 1.270v. Rebooted & Windows loaded fine. Ran Prime for just under 10 minutes with these results:

How does this look now? Why is the CPU voltage only 1.256v according to CPU-Z? Shall I keep it set to this voltage or should I lower it a bit more, or shall I just keep it set to auto (when auto, it's always at 1.272v when at full load, and 1.000v when idle)

Thanks - Liam

Plec · 16 Jul 2011 at 14:40

Quick reply just about to go out:

Temps/volts look fine - if you are thinking of sticking at 1.26V then i would consider using auto as you would at least get the advantages of the idle voltage drop as the difference is only 0.012V and temps are very similar (compared to your static voltage clock - although CPUz shows it as a 0.016V diff).

But, personally, i would carry on experimenting to see how low your chip would run at 4.4GHz. But this would be purely for the knowledge as 4.4GHz set at auto, running at ~1.27V is perfectly acceptable - some (unlucky) chips require 1.3V at this speed.

LEK-89 · 16 Jul 2011 at 14:47

Plec said:
Quick reply just about to go out:

Temps/volts look fine - if you are thinking of sticking at 1.26V then i would consider using auto as you would at least get the advantages of the idle voltage drop as the difference is only 0.012V and temps are very similar (compared to your static voltage clock - although CPUz shows it as a 0.016V diff).

But, personally, i would carry on experimenting to see how low your chip would run at 4.4GHz. But this would be purely for the knowledge as 4.4GHz set at auto, running at ~1.27V is perfectly acceptable - some (unlucky) chips require 1.3V at this speed.

Thanks Plec

I will give it a think over whether to try and go any lower, or whether to stay on auto and run Prime95 overnight tonight and see how things go.

Liam

LEK-89 · 16 Jul 2011 at 15:53

Well - I just got my first BSOD lol!

Decided to try out a bit lower and I set it to 1.260v - booted into Windows fine but then when I started Prime95 on the "in-place large FFT" test, the 3rd test window errors out and stopped and then I stopped the entire test and started again. Soon as I started the second test I got the BSOD - error 124 which means the voltage doesn't it?

Anyway - I'm back at 1.270v now so I will see how I get on.

Liam

bulldog147 · 16 Jul 2011 at 16:31

Phenomenologica said:
Your clock speed is slightly below what you set because your BCLK is at 99.8 not 100. You can afford to nudge it up if you like. Most people don't advise auto voltage for high overclocks as it can stick uncomfortable levels through the CPU, setting the voltage manually or using an offset is preferred. An offset has the benefit that it will still lower the voltage when idle. I can't advise you on the specifics as I have a Gigabyte board so am not familiar with your BIOS.

What board do you have (gigabyte is it p67 or z68 ?)

I like to know how to do offset in my vcore as it won't let me (greyed out vcore) in normal mode

LEK-89 · 16 Jul 2011 at 16:57

Well,

Worker #3 failed on Prime5 again within 2 minutes after increasing the voltage back to 1.270v, stopped the test and went back into the BIOS and upped the voltage to 1.280v and rebooted. Worker #3 failed again on Prime95 within 5 minutes so I stopped the test and once again restarted went back into the BIOS and this time set the voltage to 1.300v, idle voltage according to CPU-Z was 1.296v and for the entire time during the test, the voltage stayed at 1.288v - here are the results after running Prime for just over half an hour:

So am I right thinking that 1.288v looks like to be my safe reliable voltage figure for 4.4Ghz? If so - shall I leave it set to 1.300v in the BIOS or is it worth setting it down to something like 1.290v or 1.295v? Looks like I may have one of the "unlucky" chips

Thanks all - Liam

bulldog147 · 16 Jul 2011 at 17:06

1.3v is about right for 4.4GHz ! Mine need 1.31v thought (not a good chip I had)

LEK-89 · 16 Jul 2011 at 17:08

bulldog147 said:
1.3v is about right for 4.4GHz !

It can vary for everyone though - look at Plec's sig, 1.19v on a stable 4.4Ghz OC! :eek:

He must have a really solid chip there!

Liam

bulldog147 · 16 Jul 2011 at 17:10

It won't matter as long under 1.35V is the safer vcore for 24-7 so, 1.30v is fine, stop worry. I don't care if anyones show off with low vcore, just a big wow! but 4.4 is the same performance clock speed as everyone elses too. Plec's sig might be 1.19v at the bios due to his offset setting but I like to know where can I get offset from ?

LEK-89 · 16 Jul 2011 at 17:17

As already mentioned - I thought that the lower the voltage, the better? (as long as it's a stable voltage that the CPU can run on)

Liam

Plec · 16 Jul 2011 at 19:29

LEK-89 said:
As already mentioned - I thought that the lower the voltage, the better? (as long as it's a stable voltage that the CPU can run on)

You're right lower the better - it's about finding a balance between clock and voltage/temps. Some people want the highest attainable clock that the chip will allow and others like myself want a modest clock at the lowest voltage/heat possible so that noise is at a minimum (different strokes).

Personally, i try to run my system as silently as possible so voltage/clock ratio are very important to me (and others).

bulldog147 said:
It won't matter as long under 1.35V is the safer vcore for 24-7 so, 1.30v is fine, stop worry. I don't care if anyones show off with low vcore, just a big wow! but 4.4 is the same performance clock speed as everyone elses too. Plec's sig might be 1.19v at the bios due to his offset setting but I like to know where can I get offset from ?

Not sure what bulldogs talking/commenting about - but I have no offset as i use an MSI board - just a freaky chip when clocked under 4.5GHz.

I'm not the only member with a chip like this gurusan's was running at 1.18V @4.4GHz before he opted for a bigger clock (I should add that CPUz reports voltages of ~1.2 when running small fft).

Bragging rights (showing off(?)) usually comes with high clocks, which 4.4GHz isn't, so again bulldog's lost me. If you want offset advice, bulldog, i would start a new thread, as MSI P67 boards don't have that option.

Anyway, LEK - i would set the sytsem back to auto as your voltages and resulting temps were great - prime it for a few hours and see if it remains stable.

As mentioned before you would get the benefit of the idle voltage and the oomph when you need it at load ~1.27V.

It's a win win if 4.4GHz is the max you're after.

Plec · 16 Jul 2011 at 19:31

LEK-89 · 16 Jul 2011 at 20:15

Indeed 4.4Ghz is the max stable I am after Plec

I have just changed the voltage back to auto and I have got Prime95 running as we speak running the small FFT test (is this the best one to do?) and the voltage is sitting at 1.272v again.

So if Prime is sucessful after a few hours, is it absolutely safe for me to leave the overclock settings as they are with the voltage kept at auto?

I started Prime at 8pm, I plan to leave it running until 11pm at least. I will post if the test is sucessful/fail.

Many thanks Plec for your help, you have taught me a lot!

Lastly, you must have one good chip there for 4.4Ghz @ 1.19v!

Edit - Doh! I spoke to soon

Prime has just failed after 10 minutes with Worker no. 3 erroring out! Shall I test it with the voltage set to manual at 1.3v again?

Liam

Plec · 16 Jul 2011 at 20:47

LEK-89 said:
Indeed 4.4Ghz is the max stable I am after Plec

Edit - Doh! I spoke to soon Prime has just failed after 10 minutes with Worker no. 3 erroring out! Shall I test it with the voltage set to manual at 1.3v again?

Shame, yes i would try 1.3V with small ffts, as that will stress the CPU the most - blend combines memory and is less CPU intensive but is still a valuable test.

Don't worry if you have to lock it at 1.3V as long as it's stable and temps are OK it's nothing to worry about - you're within OcUK recommendations upto 1.35V (My CPU was an early release and they tend to be the best batch.)

The alternative is to drop the clock by 100MHz, to 3.3Ghz, as you wouldn't notice any discenable difference in speed and you may find that the system remains stable at auto (still 1GHz for free).

I was originally trying for 4.5GHz but found that the voltage/heat gains were far more beneficial at 4.4GHz - dramatically so (relative to my present voltage)

LEK-89 · 16 Jul 2011 at 20:54

Typo error there with 3.3Ghz, Plec?

I've got Prime running again now on the set 1.3v voltage (CPU-Z still reporting it being at 1.288v at full load) and Prime is currently 12 minutes in, without any problems.

Would my RAM be affecting this at all? As you know from in my previous thread - I had to manually set the RAM voltage to 1.5v for it run safely at 1600Mhz.

If it errors out again soon I will lower it to 4.3Ghz with the voltage set to auto.

Thanks Plec - Liam

Plec · 16 Jul 2011 at 20:54

Additional: What is your 'vDroop Control' set at?