# i5 2500K overclocking



## spirit (Mar 25, 2012)

I have my i5 2500K overclocked to 4.0GHz in the BIOS, yet in the BIOS it shows up as "Intel Core i5 2500K @ 3.3GHz" and the same is shown in Speccy and the system properties, yet on CPU-Z it says the core speed is 4000MHz which is 4.0GHz. Is this normal? Intel SpeedStep is disabled by the way. Temperatures are around 38C with an Arctic Cooling Freezer 13 and the mobo is a P8Z68-V PRO GEN3.

This is what I changed:

AI Tuner tab
AI Overclock Tuner - Manual
Turbo Ratio - By all cores 
Multiplier - 40x (40x100=4000=4000MHz)
Internal PLL Overvoltage - Enabled
EPU Power Saving Mode - Disabled
OC Tuner - Off
Intel SpedSteep - Disabled
Turbo Mode - Enabled

Load-Line Calibration  - Extreme
VRM Freq. - Auto
Phase Control - Extreme
Duty Control - Extreme
CPU Current Capability - 100%
CPU Voltage - Manual - 1.350 volts
DRAM Voltage - Auto (1.5 volts)
VCCSA Voltage - 1.0 volts
VCCIO Voltage - 1.1 volts
CPU PLL Voltage - 1.9 volts
PCH Voltage - Auto
CPU Spread Specture - Disabled

Advanced tab
Thermal Monitor - Disabled
CPUID Max Limitation - Disabled
Virtualization - Disabled
CPU C1E - Disabled
CPU C3 Report - Disabled
CPU C6 Report - Disabled

Monitor tab
CPU Q-Fan - Disabled
Chassis Q-Fan - Disabled

Is everything OK for an overclock of 4.0GHz or do i need to change anything else?


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## itsaferbie (Mar 25, 2012)

As long as the temperatures are good you should be fine.

Mine i5 also shows up as 3.3GHz when I've overclocked it to 4.0GHz too, only CPU-Z shows it as 4.0GHz.


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## spirit (Mar 25, 2012)

I've now got it to 4.5GHz and the temps according to Speccy at idle are around ~40C and under load (like when encoding an AVI video) the temps rise up to ~50C. are these temperatures fine or are they too high? I don't want to melt my CPU! 

Are there any other programs I can use to monitor the temperatures?


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## wolfeking (Mar 25, 2012)

core temp will monitor temps, and speedfan I think. 

But yea, those temps are good. Intel burtest is a good program to test your stability (you need to do that) and hit your max temp under 100% load. try that and see what your temps are. They should still be good.


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## Okedokey (Mar 26, 2012)

I actually use AIDA4 Extreme Edition.  What I love best is I can display on my G15 LCD keyboard screen

GTX580 Temp 1  30oC
GTX580 Temp 2  30oC
GTX580 Temp 3  30oC
12V+                 11.903V
GPU 12V+          12.172V
CPU Clock           1605MHz
CPU Utilization     0%
Used memory      1552MB
CPU Temp          35oC

I have this at all times on two switchable readouts on the screen.  makes it very easy to monitor during 3D or gaming etc.


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## MineIQ1701 (Mar 26, 2012)

Your VCCIO voltage is above the max XD, did you mean 1.0?


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## MineIQ1701 (Mar 26, 2012)

Don't mean to Hijack but I have the same mobo and processor (Differant cooler though, in sig) I have been Prime95-ing for 45 minutes now and my temp has more or less hovered at 63 degrees (c), is this acceptable temp-wise (obviously not for daily use, just the stress test)

Edit: Within 30 seconds of stopping Prime95, temps dropped to around 41 degrees (c), is that a good idle temp?


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## spirit (Mar 26, 2012)

wolfeking said:


> core temp will monitor temps, and speedfan I think.
> 
> But yea, those temps are good. Intel burtest is a good program to test your stability (you need to do that) and hit your max temp under 100% load. try that and see what your temps are. They should still be good.


Thanks for the advice Wolfe, SpeedFan reckons the CPU is running at 60C though? whereas Speccy reports 35C? I will run Burtest and Prime95 to make sure my overclock is stable. Does 4.5GHz seem about right for a 2500K on air? Too high? Too low? 



			
				MineIQ1701 said:
			
		

> Your VCCIO voltage is above the max XD, did you mean 1.0?


Nope it's at 1.9 volts. Going to lower it to 1.0 volts.


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## Okedokey (Mar 26, 2012)

lol 1.9, we have our first case of fussion inside a computer.....


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## spirit (Mar 26, 2012)

No sorry just double-checked it's 1.1 volts. CPU PLL Voltage is 1.9 volts.


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## spirit (Mar 26, 2012)

As soon as I open up Prime95 my temperatures go up to around 60C, but on idle they're around 30-35C according to RealTemp, do these temperatures seem OK? No blue screens or crashes yet so assuming my overclock is going to be stable, but I haven't run very many stress-tests yet.


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## wolfeking (Mar 26, 2012)

Stress test it for 8+ hours, I would just run it overnight to be sure. IF temps get much above 60 then kill it and lower the OC, but 60-65 or so should be fine. Just remember Stress testing it will push it to its 100% max, you will probably never see that kind of use day to day.


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## spirit (Mar 26, 2012)

Yeah I'm going to stress test it now and then see what the temperatures are like. Anything over 65C and I'm going to lower the overclock to around 4.2GHz perhaps and see what happens.


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## spirit (Mar 26, 2012)

I just got a BSOD whilst doing nothing/idle at the desktop, it was IRQL_NOT_LESS_OR_EQUAL (or something like that). The CPU is at 4.0GHz now and temps are 33C at idle. Could the BSOD have been related to the overclock? Not stressed-tested yet by the way, but I think 4.0GHz seem OK. I really don't want to ruin my CPU.


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## lovely? (Mar 27, 2012)

the overclock definitely caused the crash. i'd also check your ram for stability, downclock the processor and OC the ram to find its max speed.


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## spirit (Mar 27, 2012)

Not had any blue screens since... RAM must be fine, it's brand new and fully compatible, 1600MHz is selected in the BIOS for RAM speed.


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## M1kkelZR (Mar 27, 2012)

Sometimes RAM needs downclocking when overclocking the cpu. not sure though, i havve to to hit 4ghz on my single core crappy thing. also maybe the voltage isnt high enough for it to stay stable, because if it boots its fine but thats all it might want to do


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## wolfeking (Mar 27, 2012)

the RAM will not need any changes. He is overclocking with the multiplier, so no FSB changes.


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## spirit (Mar 27, 2012)

I've not had any problems whatsoever since that blue screen and that was the only problem which I had. Do you reckon 4.5GHz at 35-40C idle and around 60-65C under 100% load will be OK or should I stick to 4.0GHz where I'm at 30-35C on idle and about the same under 100% load? Even encoding video I'm not going to hit 100% load, perhaps 60-70% and around 50-55C at 4.5GHz. Does it seem OK or should I stick to 4.0GHz?


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## M1kkelZR (Mar 27, 2012)

wolfeking said:


> the RAM will not need any changes. He is overclocking with the multiplier, so no FSB changes.



oh sorry my bad didnt read correctly... I really need to learn to read lol


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## wolfeking (Mar 27, 2012)

its not that bad, I do the same thing a lot.


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## spirit (Mar 27, 2012)

Raz3rD said:
			
		

> oh sorry my bad didnt read correctly... I really need to learn to read lol


No worries, but yeah, it's a 2500K, doesn't have a FSB lol.  Not seen an FSB since the days of the Core 2 Duo/Quad.

So, do you reckon I should go for 4.5GHz or leave it at 4.0GHz then? Would adding the extra 500MHz mean that my CPU won't last as long or have a higher chance of frying?


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## spirit (Mar 30, 2012)

Right OK so now the CPU is at 4.5GHz and stable, but I lowered the VCore voltage from 1.35V to 1.3V and then down to 1.285V and, as expected, each time the temps got lower (good thing). I ran Intel Burn Test on each one and each time it passed, but the temperatures got lower. What is the lowest VCore voltage I should safely go to with an overclock of 4.5GHz? Reckon 1.25V would be OK or is this going to be too low? Are there any other voltages I can reduce to lower my temps as well? Thanks.


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## M1kkelZR (Mar 30, 2012)

wow im behind on everything i still have an fsb but then again i have an old rig 

but it should be stable at 4.5ghz.


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## spirit (Mar 31, 2012)

Yep it seems ok at 4.5GHz for the time being, it's not getting too hot now I have lowered the vcore voltage to 1.285v.


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## Perkomate (Apr 1, 2012)

you've got a nice chip if it's 4.5 at 1.285. Mine's at around 1.325 rock solid. Maybe because my case doesn't have airflow.


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## spirit (Apr 1, 2012)

Yeah I noticed you had your 2500K at 4.6GHz, what are your temperatures?? At 100% load I'm hitting like 66C - too high?? Recently I've been having a few problems with the PC booting, then dying, then coming back on again - think it's to do with my overclock or voltages? I may up the voltage a bit.

Edit: Pushed the voltage up to 1.3v, we'll see how it does.


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## Perkomate (Apr 2, 2012)

vistakid10 said:


> Yeah I noticed you had your 2500K at 4.6GHz, what are your temperatures?? At 100% load I'm hitting like 66C - too high?? Recently I've been having a few problems with the PC booting, then dying, then coming back on again - think it's to do with my overclock or voltages? I may up the voltage a bit.
> 
> Edit: Pushed the voltage up to 1.3v, we'll see how it does.



the only runs i've done on 4.6 were on a piss cold day with the windows open and the fan on. Temps were high 70s, too high I know, but hey; i did the run. Ambient temp was around 16 degrees C I would say.


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## spirit (Apr 2, 2012)

Hmm my PC is still turning on, then dying, then turning back on. I'm going to post a thread about it and see if any of the guys here know what the problem might be.



			
				Perkomate said:
			
		

> Temps were high 70s, too high I know, but hey; i did the run.


Whoa - waaayyy too high!! Try lowering the voltage and the frequency and see what temperatures you get then. 

And a cold day in Australia????


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## Perkomate (Apr 2, 2012)

there was one spike on one core to around 77 or so. Most of the time they were around 72 or so.
As I said, this was just one run to say that I could do it. 4.4 daily now. Now, the fan never gets <75%, ever. 
The day was in the middle of winter, in the dead of night. I was freezing my nuts off, but the PC liked it. It's coming into winter now, so I might crank it up to 4.5 for a bit. I'm a little hesitant about more than 1.32 vcore, cause i'm poor and can't afford another CPU and don't wanna risk it.

One thing I did find helped, was to run SpeedFan on the GPU and get that fan up to 100% as well, while not stressing the GPU. It moves a lot more air than just the HSF by itself. Temps down ~7 degrees across the board.


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## Okedokey (Apr 2, 2012)

Perkomate said:


> the only runs i've done on 4.6 were on a piss cold day with the windows open and the fan on. Temps were high 70s, too high I know, but hey; i did the run. Ambient temp was around 16 degrees C I would say.



Very little reason to overclock your machine actually.  Nothing on that system will make the i5 run 100% for long.  I would take the OC off completely, or at the least max it a speedstep setting (i.e. only when needed).


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## Perkomate (Apr 2, 2012)

i actually don't agree with it being very little reason. I'm compressing/uncompressing things quite a lot, and it really does help with general system speed. I had it back down to 3.3 for troubleshooting the RAM, and it just felt a little sluggish. It never really clocks up to full speed except for games, and that's where I need the extra power since my GPU is on the budget side. 
But hey, i'm an enthusiast, and this is what I enjoy.


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## spirit (Apr 2, 2012)

I've now got my 2500K back to the stock 3.3GHz for the time being because I was having problems with the PC booting incorrectly as I mentioned earlier. My BIOS came up earlier this morning and said "overclocking failed!" so I reset the BIOS.


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## Perkomate (Apr 2, 2012)

I get that sometimes on my board. Bumped up the voltage, got the RAM sorted and it's fine. Also sometimes happens when waking up from sleep mode. 
I've been reading around, and Intel says that up to 80 degrees for short periods of time is fine.


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## Okedokey (Apr 2, 2012)

Perkomate said:


> ...except for games, and that's where I need the extra power since my GPU is on the budget side.
> But hey, i'm an enthusiast, and this is what I enjoy.



That was my point.  A 5770 isn't going to properly tax a stock i5.



Perkomate said:


> ...Intel says that up to 80 degrees for short periods of time is fine.



Reference?


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## spirit (Apr 2, 2012)

Perkomate said:
			
		

> I get that sometimes on my board. Bumped up the voltage, got the RAM sorted and it's fine. Also sometimes happens when waking up from sleep mode.


Yes it's happening when waking up from sleep as well. :/ So you sorted out by upping the voltage and sorting out the RAM. What do you mean by "sorting out the RAM"?? 



			
				Perkomate said:
			
		

> Intel says that up to 80 degrees for short periods of time is fine.


80C is way too hot, anything over 70C is probably too hot.


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## Perkomate (Apr 2, 2012)

well, Tcase max is 72.6 degrees (no idea why so specific). Actual core temp is ~10-15 degrees higher than this, so around 82.6 to 87.6 degrees. It's all over the web, i'm still trying to find the exact Intel datasheet for it.


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## Perkomate (Apr 2, 2012)

vistakid10 said:


> Yes it's happening when waking up from sleep as well. :/ So you sorted out by upping the voltage and sorting out the RAM. What do you mean by "sorting out the RAM"??



my timings were't quite right. My RAM is optimised for H67 boards (IIRC), so it was default at 9-9-9-24. I changed it to 9-10-9-24, and no problems. Volts went up by 0.005 and that helped too.


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## spirit (Apr 2, 2012)

My RAM is at 9-9-9-24, are these timings right? or should i change them? I'd like to overclock but I want it to be stable, which my previous one wasn't apparently.


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## Okedokey (Apr 2, 2012)

Perkomate said:


> well, Tcase max is 72.6 degrees (no idea why so specific).



Because the expansion of the case (thermal cap) of the CPU is very accurate.  Metals expand proportionally to temp, so they know the limits.  Intel are pretty conservative though.  But anything over 70 would make me uneasy.


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## Perkomate (Apr 2, 2012)

try 9-10-9-24 and see what happens. Sleep the computer and wake it up a few times. If it doesn't fail boots, then it's probably the RAM.


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## spirit (Apr 2, 2012)

OK I will do thank you for the suggestion.


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## Perkomate (Apr 2, 2012)

bigfellla said:


> anything over 70 would make me uneasy.



yeah, i was on the verge of stopping the test. I was using Intel Burn, which is notorious for higher temperatures. I might wait for a cold day and do a few runs of Prime95.
The temps during gaming never get anywhere near that level though. Round 60 is the highest I've ever seen, and that was during Crysis 2 with an overclocked GPU in the middle of summer.


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## spirit (Apr 5, 2012)

In my BIOS there are 3 operating options - 'Power Saver', 'Normal' and 'Performance' (which is referred to as 'ASUS Optimal Mode' in the manual). I selected Performance and the motherboard changed the following:

CPU ratio 103
Multiplier 42x
Target Turbo Mode Frequency = 4.3GHz (103x42)
DRAM frequency 1648MHz
DRAM voltage 1.5V
CPU voltage 1.160V (offset)
VVCIO voltage 1.059V
CPU PLL 1.796V
PCH voltage 1.075V

Assuming that because the BIOS has made these changes itself once I selected Performance it's all going to run fine? I can easily go back if not.

I did some Googling and apparently it's stable to use - we'll see how I get on with it.


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