Help Overclocking the Corei5 2500k

[handsome_dave]

Hi!

So i've decided to overclock my 2500k, and this is the first time i've ever done anything any overclocking. My first question is this: I downloaded cpu-z and for some reason my cpu idles at 1.6Ghz, and when I do something a bit more cpu intensive, it goes to 3.3Ghz, and if i do something even MORE cpu intensive, it hits about 3.6Ghz. I thought my cpu was suppose to idle at 3.3 Ghz and when i do something more cpu intensive, it'll turbo to 3.8ghz or so. Why is that?

Secondly, how would I even start with the overclock? In the Bios, the multiplier is set to 33 (but in cpu-z, i see 16 when my cpu is idling...) with auto voltage. I've read some threads and OC'ing seems like a balancing act. I want to OC to 4Ghz with approximately 1.25V. So Do i just set this manually? Do I have to turn off turbo? (If so, how?). What is LLC? Do I have to play around with it? Is there anything else I should look out for? I've tried following this guide but to no avail. Thanks!

 

[Zap]

You are over-thinking things.

1.6GHz is idle speeds. 3.3GHz is the clock speed of the CPU. "Turbo" speeds are possible when conditions are right. That is by design.

How to overclock a 2500k to 4GHz.
Step 1. Set the Turbo multiplier(s) in BIOS to your desired speed (40x).

There! Wasn't that easy?

 

[sangyup81]

LLC is a bit controversial but I'm one of the ones that turn it off and raise the idle voltage in bios to compensate. The reason is that I get lower temps and that I'm not convinced that LLC works perfectly. There have been articles about LLC causing voltage spikes so I'd rather do without it

 

[betasub]

for some reason my cpu idles at 1.6Ghz

It's for a very good reason, as intended by Intel.

 

[sticks435]

You are over-thinking things.

1.6GHz is idle speeds. 3.3GHz is the clock speed of the CPU. "Turbo" speeds are possible when conditions are right. That is by design.

How to overclock a 2500k to 4GHz.
Step 1. Set the Turbo multiplier(s) in BIOS to your desired speed (40x).

There! Wasn't that easy?

I'm surprised you didn't use the 3 step "profit" meme lol.

 

[Subyman]

It seems you aren't too knowledgeable on CPU's in general. I would do a lot of research before touching the BIOS if you are a newbie to the hardware scene. There is a lot to learn!

Here is a good link to get started:

http://www.bit-tech.net/hardware/cpus/2011/01/07/how-to-overclock-the-intel-core-i5-2500k/1

 

[Zap]

I'm surprised you didn't use the 3 step "profit" meme lol.

I usually do, LOL, but in this case it would be 2 steps too many.

 

[sticks435]

haha, yea true. I'm about to build my 2500K system, I'm sure I'll be tweaking a few more settings though, since I want to get around 4.5 to 4.8.

 

[Crap Daddy]

On SB mild overclocking is very easy. In fact anyone can do it. By saying "mild" I am thinking of up to 4.3-4.4 GHZ which is very impressive in comparison with the last generations of Intels. So for a beginner all you have to do is set the multiplier to the desired ratio and leave everything else on auto, voltage included. You'll have around 1.25 to 1.28 V on vcore for 4.0GHz. All you need extra is an aftermarket cooler which is mandatory for any OC.

 

[Borealis7]

step 1: Set your multi to x40.
step 2: Stress test the cpu.
step 3: Profit! (for the electric company...)

 

[Shmee]

all you should need to adjust is core multi and vcore. these are quite simple to OC, as opposed to on the x58 platform. try balancing vcore, vtt/uncore voltage, core multi, QPI mode, BCLK frequency, uncore ratio, memory ratio. :O

oh, and then there is always PLL voltages and memory timings, but your board probably has that too.

 

[handsome_dave]

Thanks everyone! So all I have to do is set the multiplier to x40 and i'll be good? I'm changing it just like this review did.

Can someone also tell me why my idle is 1.6Ghz (according to cpuz) when my multiplier is currently set to x33? shouldn't I be idling at 3.3Ghz? And how come there is no 'turbo multiplier' so I change my turbo to what I like? So when I change the multiplier, what is it actually doing?

 

[Shmee]

hey, I recommend you read the stickies, everything should be there as far as stress testing and power saving features goes.

to answer your question shortly, when idle, most modern CPUs downclock themselves. though you may have raised the multi, that is the multi your CPU will use when there are more demanding apps running. Trust me, it is still overclocked, but only when needed.

also, download occt for stress testing. for more info, check the sticky threads

 

[handsome_dave]

Thank you!! Will do and I will report back here if I have any other questions. I love this forum! So helpful for noobs like me

 

[BonzaiDuck]

It seems you aren't too knowledgeable on CPU's in general. I would do a lot of research before touching the BIOS if you are a newbie to the hardware scene. There is a lot to learn!

Here is a good link to get started:

http://www.bit-tech.net/hardware/cpus/2011/01/07/how-to-overclock-the-intel-core-i5-2500k/1

Dr. Professor Lord Subyman -- Scholar . . . Gentleman. . . Prince-Among-Men. Thanks! For that Bit-Tech link! Another addition to my library of "intel" about Intel Sandy-Bridge, but . . . what an addition! Quite Fine!

Too bad . . . I can't treat you to a Mexican Dinner in Cyber-space, or fix for you my very own blue-corn Tostadas . . . .

 

[handsome_dave]

Hey guys!

Okay so I read the the link, changed the multiplier (x40) and the vcore setting (1.300V) and then did a stress test with prime using small FFT. Everything seemed to be stable (no error or BSOD). However, i decided to go back to default settings so I changed my multiplier to x33 and vcore to auto. Now my temperatures are higher than before (about 3C higher) and I even left it over night and checked this morning with the temps still higher than what it was before I OC to 4ghz. What could be the problem?

I also noticed another issue. Coretemp reports that my VID voltage is 1.226V or something close. Previously before my OC, it was about 0.9V?! and now its a constant 1.226V. what did i do?! For some reason, cpu-z reports that i'm idling at 3.3Ghz now and i no longer idle at 1.6ghz. FML. I think i effed something up. Please help!!

 

[BonzaiDuck]

Hey guys!

Okay so I read the the link, changed the multiplier (x40) and the vcore setting (1.300V) and then did a stress test with prime using small FFT. Everything seemed to be stable (no error or BSOD). However, i decided to go back to default settings so I changed my multiplier to x33 and vcore to auto. Now my temperatures are higher than before (about 3C higher) and I even left it over night and checked this morning with the temps still higher than what it was before I OC to 4ghz. What could be the problem?

I also noticed another issue. Coretemp reports that my VID voltage is 1.226V or something close. Previously before my OC, it was about 0.9V?! and now its a constant 1.226V. what did i do?! For some reason, cpu-z reports that i'm idling at 3.3Ghz now and i no longer idle at 1.6ghz. FML. I think i effed something up. Please help!!

Are you sure you "saved" the BIOS changes? Or did you take "Turbo mode" off "auto" before saving it? Any number of things. You might just go back, CLR-CMOS after recording the desired settings, and re-configuring according to you recorded notes . . .

But I'd notice the same thing about CoreTemp VID and CPU-Z VID, in contrast to my ASUS AI-Suite monitor which seems totally consisent and accurate.

 

[Zap]

haha, yea true. I'm about to build my 2500K system, I'm sure I'll be tweaking a few more settings though, since I want to get around 4.5 to 4.8.

4.2GHz is easy. 4.5GHz is not unknown. 4.8GHz... is a bit tougher and will probably require tweaking and a bit of luck.

Thanks everyone! So all I have to do is set the multiplier to x40 and i'll be good?

Like I said above, yes.

Can someone also tell me why my idle is 1.6Ghz (according to cpuz) when my multiplier is currently set to x33? shouldn't I be idling at 3.3Ghz? And how come there is no 'turbo multiplier' so I change my turbo to what I like? So when I change the multiplier, what is it actually doing?

Did you read what I said above? Apparently not.

Okay so I read the the link, changed the multiplier (x40) and the vcore setting (1.300V)
...
Now my temperatures are higher than before (about 3C higher) and I even left it over night and checked this morning with the temps still higher than what it was before I OC to 4ghz. What could be the problem?

I also noticed another issue. Coretemp reports that my VID voltage is 1.226V or something close. Previously before my OC, it was about 0.9V?! and now its a constant 1.226V. what did i do?!

You messed with stuff that you didn't need to. Like I said above, all you needed was to set 40X multiplier. See if you can recover by clearing BIOS.

 

[handsome_dave]

You messed with stuff that you didn't need to. Like I said above, all you needed was to set 40X multiplier. See if you can recover by clearing BIOS.

Hi Zap,

I did what you said and only played with the multiplier at first. After setting it to x40, Vcore was at 1.35V, which I thought was too much for just 4Ghz, so i reduced it to 1.30V. These were the only two settings I touched. Now when I revert things back to default (by setting multiplier to x33 and Vcore to auto) i get higher temperatures and whats more odd is that Coretemp now shows my VID voltage at 1.2260 constantly instead of 0.9V as before. I didn't play with any other feature in the bios. Should I clear my CMOS? Will it restore everything to what it was or will I have to do something to the bios after i reset it? Thanks for all your help

 

[BonzaiDuck]

Hi Zap,

I did what you said and only played with the multiplier at first. After setting it to x40, Vcore was at 1.35V, which I thought was too much for just 4Ghz, so i reduced it to 1.30V. These were the only two settings I touched. Now when I revert things back to default (by setting multiplier to x33 and Vcore to auto) i get higher temperatures and whats more odd is that Coretemp now shows my VID voltage at 1.2260 constantly instead of 0.9V as before. I didn't play with any other feature in the bios. Should I clear my CMOS? Will it restore everything to what it was or will I have to do something to the bios after i reset it? Thanks for all your help

Sorry I'm too preoccupied right now to go back and search what you may have mentioned in earlier posts, as much as I read through most of them once.

I also mentioned that CoreTemp, RealTemp and CPU_Z -- which I've installed and run -- are not reporting accurate VIDs, accurate CPU/system clock-speeds. Nor does "Z" report current memory states of CAS, RCD, RP and RAS or any other latency states.

I also said that all of my ASUS monitoring software is working, and seems to be accurately reporting the temperatures and the other features I mentioned -- in addition to just about everything else I can think of.

The sharewares are all the latest revisions, but the revisions' dates all precede the release of chipset Z68 motherboards. Some by a month or two, others by a few months; one or more a half-year old.

 

[MTDEW]

Hi Zap,

I did what you said and only played with the multiplier at first. After setting it to x40, Vcore was at 1.35V, which I thought was too much for just 4Ghz, so i reduced it to 1.30V. These were the only two settings I touched. Now when I revert things back to default (by setting multiplier to x33 and Vcore to auto) i get higher temperatures and whats more odd is that Coretemp now shows my VID voltage at 1.2260 constantly instead of 0.9V as before. I didn't play with any other feature in the bios. Should I clear my CMOS? Will it restore everything to what it was or will I have to do something to the bios after i reset it? Thanks for all your help

First, you can just load bios defaults if you're not sure you have everything set back the way it was instead of clearing the CMOS.

Coretemp now shows my VID voltage at 1.2260 constantly instead of 0.9V as before.

With Sandy Bridge cpus the VID is dynamic and based on clockspeed.
And its slightly different for each individual cpu.
So if you were 0.9xx before and you're at 1.226 now, its probably because your cpu was at 1.6ghz or so before when you checked and is at 3.3ghz or so now which gives you a higher VID.
It also explains your higher temps.

The VID your cpu reports with all the extra stuff turned off(c1 eist, c3, c6) and turbo disabled, is the voltage intel set for that particular cpu to be stable at that given speed.
Now that doesn't mean it cannot be stable at a lower voltage since obviously Intel doesn't set them to "ride the line of stability".
They are set a bit higher than actually needed for stability.

So in short, to check your personal cpus VID for any given speed, disable c1 eist, c3, c6 and turbo in the bios and you can check the default VID for each given speed.

Here is a chart with the "general" VIDs for SB CPUs.

 

[guskline]

handsome dave: What Motherboard do you have? I have an ASRock Z68 Extreme4 just as MTDEW has above and I just used the auto setting for 4.4ghz and my voltage goes as high as 1.325v (which is ok for stability). Also what CPU cooler and case do you have? These factors help with giving an answer. I notice from his sig that MT has a 2600k OC to 4.6ghz with voltage at 1.245v. I imagine he is using manual settings.

 

[handsome_dave]

guskline: I have a MSI P67A-C43 motherboard. I'm not a big fan of it since the onbard audio came with a hissing sound but if I were to RMA it, i'd probably have to wait a month so I think i'll just deal with that. As for my OC problem, i Cleared the CMOS and everything was back to normal. Hitting temperatures of 28/32C on core 1/3 and 35-42 on core 0/2.

What are safe operating temperatures when you overclock? When i changed the multiplier to x40, temps went to around 70C (only on core 2) when using small fft with prime.

MTDEW: I understand the VID voltage is dynamic, but how come coretemp shows something like 1.119V while CPU-Z shows something like 0.9xxV? :S

 

[MTDEW]

Cpu-z displays only current actual core voltage not the VID.
Core Temp displays only the VID not actual current core voltage.

VID - is what voltage Intel says the CPU will need and is reported by the processor itself and is what Core Temp displays.
Core Voltage - Is the actual current cpu voltage and is read from a sensor and that is what CPU-Z displays.

Even if you have everything on auto , the values are unlikely to ever match exact due to vdroop , LLC etc..etc..

Also, the current version 0.99.8 of core temp has a problem with detecting the CPU frequency on SB cpus, and also doesn't show a Model string.
Things such as Tj-Max and temperature are still correct though.

That is why i suggested disabling turbo, eist, c1e etc.. etc... while checking for the default VID for any given core speed of your cpu.

Depending on your motherboard, the VID may also be shown in the bios.

 

[Zap]

What are safe operating temperatures when you overclock? When i changed the multiplier to x40, temps went to around 70C (only on core 2) when using small fft with prime.

70ºC is within the operational limits, so don't worry about that as a fully loaded temperature.

Unless the entire purpose of your rig was to be fully loaded all the time, your normal temperatures should be lower than the fully loaded temperature.