i5-2500K Overclock Guidance

dg170775

dg170775

dg170775

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All,

I'm currently trying to achieve the highest stable OC I can get out of my 2500K. I initially had several BIOS issues with my P8Z68-V Pro/GEN3 but I've finally managed to cure all those niggles and have a stable motherboard with the latest BIOS (3202).

My current modest OC is 4Ghz @ 1.36v withe the H100 cooler, temp. around 62C. I know that the voltage is on the higher side and that's where my question arises. While overclocking, there are a few ways to set voltages:

1. Set voltage Manually by entering required values
2. Use Offset mode, to enter either a +/- offset value
3. Auto

I am current set at the offset mode, with the offset value at Auto. And with that setting for voltages, I get a Vcore of 1.36v under load. Looking at the other posts here in the forum, that looks to be quite high for a 4Ghz OC.

So, I would like some guidance on what's the best way to set voltages. Secondly, which are the other parameters in the BIOS that I can tweak to get a Stable OC, with less voltage & heat?
 
Drop manual till unstable then up one, would think you can get to aground 1.2v foe 4ghz depending on your chip.

Once you have a low manual voltage you can begin calculate the offset.
 
Yeah 1.36V is a little high for your overclock but auto volts will do that. As pgi947 says drop the voltage manually and test for stability. Keep repeating till it's unstable and then move back up a notch so that you're at the last stable voltage.

Then note the figure down and calculate the offset from that. There's no sure fire way to overclock, you'll have to mess about with the bios settings and test.

You want to enable LLC I would say and look back in the forum if you can. There'll be some settings to try in the forum somewhere if you wanna be lazy :p
 
Ok, I've gone through a couple of guides and done as instructed in the guides, and here's my stable 4Ghz OC

Voltage in BIOS - 1.2v
VCore under load in CPU-Z - 1.176 - 1.184
Average Temperature across 4 Cores - 52C
Prime95 run for 10 hours.

Settings in BIOS
RAM Profile set to XMP @ 1866Mhz (8GB Corsair XMS3 2000Mhz)
LLC = High (Will Ultra High / Extreme help?)
Multiplier - 40 (100X40) Voltage - 1.2v
C1E and SpeedStep enabled
C3 and C6 Auto
Intel Spread Spectrum Enabled
CPU Capability 140%
Phase Control - Optimised
Duty Control - T.Probe
EPU Power Saving - Disabled
CPU PLL Overvoltage - Disabled

All other settings are AS-IS.

So, is there something that looks out of place, in the above Settings?
Secondly, is there a way to get the Temperature AND/OR Voltage down a notch?

Or is this the best I can squeeze out? I tried with 1.19v in the BIOS and Prime95 threw a FATAL ERROR after 5 minutes.

EDIT: The above OC is with my H100 at its lowest (quietest) setting.
 
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Looks pretty damn good to me!

Higher LLC may help, but I found it more effective at higher clocks. You could probably reduce the CPU cap too.
 
pgi947 said:
Looks pretty damn good to me!

Higher LLC may help, but I found it more effective at higher clocks. You could probably reduce the CPU cap too.
Click to expand...

But, I'll be going for higher overclock now. This was the first step. So, I might need the CPU Capability setting.
You're right about LLC too, but, like I said I'll change it to Ultra once I go for higher clocks.
 
How high do you want to take it? as certain settings are recommended to be changed for higher speeds.

Check out clunks p67 guide (google just that;)) but you can probably ignore the memory side of things.
 
Ok, here's my 4.5Ghz OC Setting, with a quick 30 minutes Prime95 FT 1344 run, with 90% RAM.

Voltage in BIOS - 1.32v
VCore under load in CPU-Z - 1.32 - 1.328
Average Temperature across 4 Cores - 65C

Settings in BIOS
RAM Profile set to XMP @ 1866Mhz (8GB Corsair XMS3 2000Mhz)
LLC = Ultra High
Multiplier - 40 (100X45) Voltage - 1.32v
C1E and SpeedStep enabled
C3 and C6 Auto
Intel Spread Spectrum Enabled
CPU Capability 140%
Phase Control - Optimised
Duty Control - T.Probe
EPU Power Saving - Disabled
CPU PLL Overvoltage - Disabled

All other settings are AS-IS.

So, any thoughts around the voltages that I'm using for 4500Mhz OC? Is 1.32v a good voltage, and is there room to push further, looking at voltage & temp.?
 
pgi947 said:
How high do you want to take it? as certain settings are recommended to be changed for higher speeds.

Check out clunks p67 guide (google just that;)) but you can probably ignore the memory side of things.
Click to expand...

Well, this's more of an experiment, to see how far can my chip go, keeping voltages and temp. in check..

I'm currently @ 4.5Ghz with 1.32v, and I guess I'll try till 1.4v to see where I get.. maybe 4.6-4.8Ghz ?

Btw, I have that guide, and been reading that ..
 
its a good guide and good starting point :)

I would say leave it at 1.32v and start upping the MP until unstable then raise voltage, this is what I did and to my surprise found I have a good chip and was able to go all the way to 4.8ghz on 1.312/1.32v.

Edit: You have headroom on the temps to go higher, the H100 is on par if not slightly better (cooling wise) than the high end air coolers.
 
pgi947 said:
its a good guide and good starting point :)

I would say leave it at 1.32v and start upping the MP until unstable then raise voltage, this is what I did and to my surprise found I have a good chip and was able to go all the way to 4.8ghz on 1.312/1.32v.

Edit: You have headroom on the temps to go higher, the H100 is on par if not slightly better (cooling wise) than the high end air coolers.
Click to expand...

Trying out with 46 multiplier and I've gone all the way from 1.32 to 1.36, to get a stable run. Prime95 running since the last 15 minutes..
VCore in BIOS = 1.37v
Vcore in CPU-Z fluctuates between 1.368v - 1.376v
Temp. across 4 Cores = 69.5C

So, if Prime95 runs for sometime now without errors, then 47 multiplier, here I come :)
 
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pgi947 said:
Try putting Phase and Duty to extreme too and see if it improves things :)
Click to expand...

Yeah, will have to look at those settings now, as I seem to have got a stable 4.6Ghz overclock @ 1.368v, temp. 69.5C

So, will let Prime95 run for some more time, and then go for 47X.

EDIT: Which are the other settings that I need to be wary of?
 
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Still using prime?, why...

Intel Burn test, you can easily pass prime and fail intel burn test :p

If you pass IBT at 1.344 4.8ghz i'll be surprised
 
I'm stable at the moment, with 4.6Ghz @ 1.368v. I can't get the volts to come any lower.
So, now as I start trying for higher OC, what are the BIOS parameters I need to tweak.
Also, I need to ensure that my system is not always at 4.X OC, and clocks down when it's being nominally used (like my better half surfing, etc)
 
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