First Overclock/ (Some questions re. vcore)

[Marksman12]

Hey guys, so I overclocked my i5-2500k from its stock 3.3ghz to 3.6ghz with temps at idle average 45-47C with the STOCK cooler. I just purchased the Cooler master Hyper 212 so I will install that when it gets here and plan to bring it to at least 4.0ghz.

Right now with the stock cooler and OC'd to 3.6, the vcore is at 1.288V with the idle temps I listed above (45-47C).

My question is, is this vcore too high, and will a after market cooler, like the one i purchased, have any affect on the vcore (such as lower it)? My vcore is set to Auto, so i did not manually make any changes to it. I have read many different views on how high the vcore should be. Some people say a safe 24/7 OC can be between 1.40v and 1.45v and others say it should never go above 1.30v.

What is your guys opinion on this? Once I get my cooler I am going to attempt to go to 4.0 ghz which I know this CPU can do, however I am suspecting the vcore to be above 1.3 (my guess is around 1.35-1.36v). Is that a safe vcore, or is that going to slowly kill my cpu?

[potis]

1.288V is too high for only 3.6Ghz, you can probably do 4.2-4.3Ghz with that much VCore on Sandy Bridge.

Sandy Bridge voltage scaling starts after 4.4Ghz which is about 1.290 to 1.3Vcore then suddenly for 4.5Ghz jumps to 1.330V Vcore and above on good chips, most require 1.340V.

Auto overclocking is a massive NO, especially when you dont have a proper strong cooler to counter any stupid overvolting by bios.

Every chip is obviously different but a general image of Sandy Bridge voltage from my research and my own i7 2600K basically same chip as yours.


Coolermaster Evo 212 can handle 4.2Ghz easiy since the voltage change isnt as massive.

[Marksman12]

So, should I try manually lowering the vcore?

[potis]

You dont overclock like that.

You overclock like this:

General image from reading on the internet was similar people did with your CPU and SAME MOTHERBOARD.

Then general image what the chip does overall with ANY MOTHERBOARD.

General image of settings Off/On on your OWN MOTHERBOARD.

Then you try yourself. You read and try as example with a quick 10 minute proper research you can see everyone has their i5 2500K/i7 2600K at 1.340V core and above for 4.5Ghz.

Thats your goal basically on a good cooler, since you dont have such a good cooler, lower your goal at 4.2Ghz as example.

4.2Ghz can be achieved on GREAT chips at 1.250-1260V, on most chips at 1.280V-1.290V Vcore, so start from there.

The default stock Vcore for any i5 2500K varries from 1.2V to 1.250V, depends on the chip.

As example how to start after you read what to disable for P67/Z68/Z77 depending on your motherboard.

Set Vcore to 1.280V and let Windows open, did it freeze? Something is wrong, try 1.285V, repeat etc.

Assuming nothing froze or BSOD, run Linx/IBT to check stability.

[Cilraaz]

I'm currently running my 2500k at 4.6GHz with a 1.35V vCore. I've been running it like that since the 2500k was the new chip on the block.

Your vCore typically isn't affected by the cooler that you use. Each CPU out there requires a different amount of voltage at different speeds. A great 2500k might only need 1.29V at 4.8GHz. My setup is fairly average. A bad chip might need 1.35V at 4.0 or 4.2GHz. Finding out your minimum vCore at your chosen speed is half the work of overclocking.

As far as limits for your 2500k... You're essentially not wanting to go over 1.4-1.45V. The reason some people say 1.3V is because of a setting called Load Line Calibration. This setting helps your system maintain its vCore voltage. As you increase load on a CPU, the voltage will naturally dip. LLC adjusts vCore for this to help offset the dip. When the load suddenly goes away, LLC will stop the voltage compensation. Unfortunately, this happens at a slight delay. As such, the voltage spikes for a fraction of a second. If you are pushing the upper limits of vCore (say 1.42V), when the load goes away, your vCore may spike upwards of 1.55V for a fraction of a second until LLC realizes load has ceased and stops assisting. I don't know if anyone has proven that this can/will cause either direct damage or degradation, but I'd personally rather be safe than sorry.

I would suggest no more than 1.40-1.42V if not using LLC. If you do use LLC (use as low of a setting as possible, you DO NOT want your vCore to increase under load), I would try to cap it around 1.35V. These are just my own personal suggestions, though.

[Fascinate]

Set your bios to default and just change the multiplier to 42, the standard voltage setting on the motherboard (called adaptive on most) will ramp up the volts with a multiplier change. This is usually slightly higher volts than manually setting it and using offset, but not by much.

Dont use fixed, thats the caveman way of overclocking keep all the power saving features enabled. Literally just set bios to default and change the multiplier, you should load at around 1.25-1.3v with a 4.2ghz overclock.

[Cilraaz]

Dont use fixed, thats the caveman way of overclocking

You suggest instead allowing the motherboard to determine vCore?

[Fascinate]

You suggest instead allowing the motherboard to determine vCore?

Like i said above adaptive will give your CPU slightly more volts than you could manually tune in using offset voltage, but no one should be using fixed. Use either adaptive or offset, never fixed.

[Cilraaz]

Like i said above adaptive will give your CPU slightly more volts than you could manually tune in using offset voltage, but no one should be using fixed. Use either adaptive or offset, never fixed.

Any reasoning behind that (actually curious; not being sarcastic)? Personally, I was never able to get offset to be stable (typically either load voltage was too high or the system blue screened when load dropped) and auto-voltage pushed WAY more than I'm able to run stable with a fixed vCore.

[Marksman12]

Set your bios to default and just change the multiplier to 42, the standard voltage setting on the motherboard (called adaptive on most) will ramp up the volts with a multiplier change. This is usually slightly higher volts than manually setting it and using offset, but not by much.

Dont use fixed, thats the caveman way of overclocking keep all the power saving features enabled. Literally just set bios to default and change the multiplier, you should load at around 1.25-1.3v with a 4.2ghz overclock.

I shouldnt do that though until I have the new cpu cooler right? Going 4.2 with stock cooler would be a bad idea i take it?

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By the way I am also using the MSI p67A-G43 mobo.

[Fascinate]

Because fixed is just super inelegant. Why would you want a full ~1.3v or more going to your CPU when just web browsing? This will effect cpu lifespan and heat output. Offset is more work to get stable, but its the proper way of doing an overclock on sandy bridge or higher. I also leave speedstep enabled, clocks up to 4.2 with a load and right back down to 1600 (i think on newer intels its 800mhz even) when idle.

I actually use adaptive right now for my everyday overclock but to get HIGH overclocks you need to do offset (most boards adaptive wont function correctly after ~4.4ghz). My 4.9ghz overclock is using offset and it works perfect, you just need to find a balance of low enough idle volts and high enough load volts.

[Cilraaz]

I shouldnt do that though until I have the new cpu cooler right? Going 4.2 with stock cooler would be a bad idea i take it?

You can always try it and see how it goes. If the temps are too high, then you can back it down some until the 212 shows up.

[Fascinate]

I shouldnt do that though until I have the new cpu cooler right? Going 4.2 with stock cooler would be a bad idea i take it?

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By the way I am also using the MSI p67A-G43 mobo.

Ouch MSI. Back then offset overclocking was new and MSI is the ONE manufacturer that did not implement a proper offset on their p67 boards. Im not even sure they have a proper adaptive setting, i just remember to avoid them back when i was shopping for my rig lol. You may have to use fixed volts on that board, just google your motherboard number and then "overclocking" to find out. And ya id probably wait until you get your cooler to try anything over 1.25v.

And to answer your original question, sandy bridge is a tough ass CPU id say anything under 1.4v is safe. (once you get your cooler of course). I prefer to keep mine at 1.296v cause im kind of a pussy, but i know lots of people that have ran theirs over 1.4v for over 4 years now.

[Marksman12]

Ouch MSI. Back then offset overclocking was new and MSI is the ONE manufacturer that did not implement a proper offset on their p67 boards. Im not even sure they have a proper adaptive setting, i just remember to avoid them back when i was shopping for my rig lol. You may have to use fixed volts on that board, just google your motherboard number and then "overclocking" to find out. And ya id probably wait until you get your cooler to try anything over 1.25v.

And to answer your original question, sandy bridge is a tough ass CPU id say anything under 1.4v is safe. (once you get your cooler of course). I prefer to keep mine at 1.296v cause im kind of a pussy, but i know lots of people that have ran theirs over 1.4v for over 4 years now.

Ok thanks for the info. I installed MSI live update. I updated my bios etc. There is an option for OC Genie.. Should I stay away from that?

[Fascinate]

You can try that, that works on the same basis as adaptive. My guess is it will give you a 4.2ghz overclock at around 1.3v. If you run any stress tests after dont let the CPU go above 80c.

[Marksman12]

You can try that, that works on the same basis as adaptive. My guess is it will give you a 4.2ghz overclock at around 1.3v. If you run any stress tests after dont let the CPU go above 80c.

Ok, I just enabled OC genie and it brought VCORE to 1.336 @ 4.2GHZ. Average idle temp is 50C.

Obviously the temps will be lower with my new cooler. However, regarding the vcore, should i try a fixed vcore instead to lower it?

[Fascinate]

Ya thats pretty high for 4.2 lol. 1.336 isnt a dangerous vcore, just a bit high for that OC. I have the CM 212+ also and my 4.2ghz OC is 1.296v and it never goes above 60c under full load, idle is 24-28c.

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Obviously the temps will be lower with my new cooler. However, regarding the vcore, should i try a fixed vcore instead to lower it?

Nah i wouldnt, having a slightly higher load vcore using that software is better than having a ~1.3v constantly going to your CPU. It is clocking down the volts and CPU speed at idle right?

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If you havent tried it yet disable that software go into your bios and set everything to defaults, then just change the CPU mulitplier to 42 save and exit. Once in windows see if its clocking down to 1600mhz and if volts are going down to .972ish. While you are in the bios you can also enable xmp if your ram supports this.

[Marksman12]

Ya thats pretty high for 4.2 lol. 1.336 isnt a dangerous vcore, just a bit high for that OC. I have the CM 212+ also and my 4.2ghz OC is 1.296v and it never goes above 60c under full load, idle is 24-28c.

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Nah i wouldnt, having a slightly higher load vcore using that software is better than having a ~1.3v constantly going to your CPU. It is clocking down the volts and CPU speed at idle right?

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If you havent tried it yet disable that software go into your bios and set everything to defaults, then just change the CPU mulitplier to 42 save and exit. Once in windows see if its clocking down to 1600mhz and if volts are going down to .972ish. While you are in the bios you can also enable xmp if your ram supports this.

Ok i set the defaults and it is running 1.336v with constant 4.2ghz. But I think thats because CE1 is disabled, i enabled it last time and it brought it to 1600ghz with like .99-1.1 v idle.

[Fascinate]

Thats very odd, thats first motherboard ive seen that disables C1E at default settings. Yes enable that, as well as speedstep.

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Was your CPU and volts throttling down at load with the MSI OC genie?

[Marksman12]

Thats very odd, thats first motherboard ive seen that disables C1E at default settings. Yes enable that, as well as speedstep.

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Was your CPU and volts throttling down at load with the MSI OC genie?

No it wasnt. I am guessing by just switching the multiplier and leaving speedstep/ce1 enabled I should be ok? Also, as far as temps go (until my cooler gets here) I should be fine at these setting correct? I brought it to 4.0ghz, max vcore 1.304 and temps around 50-60C when playing world of warcraft which is what I mostly only play anyways.

In what situations would I ever be near the stress test limits??