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2500K Overclocking Help

Rooster212

Rooster212

Rooster212

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22 May 2011
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Manchester
I've built my new PC (:D) using an i5 2500K and a Gigabyte GA-Z68X-UD4 and am very happy with the performance I am getting out of it.

However, using an H70, I would think i would be able to go over 4.4GHz stable (which is what I have it at atm). I had it at 4.6 yesterday but it failed the Prime95 test after around 20 mins!

Current settings are as follows:

Multiplier: 44x
BCLK: 100MHz (Pretty sure this isn't supposed to be modified)
CPU Load Line Level: 5 (Could maybe put this up?)
CPU VCore: 1.38V (I know this shouldn't be any higher)
DRAM Voltage: 1.55V
RAM Speed: 1866MHz

What I would like to know is, what other settings could I modify to get this OC higher (or settings above that should be modified) I know the Sandy's should be able to get higher, especially under H70 cooling. Temps atm are around 60C at full CPU load, but that is with the fans pushing hot air out of the case through the radiator so think I am going to change that soon and draw in air through the radiator in push-pull so temps can go lower.

Going to stress test 4.4GHz overnight, pretty sure it should be fine as I've been gaming on it for around 4 hours today so it should be ok. :D
 
There's another CPU-related voltage that usually has to be increased...PLL or something?

Otherwise, it could just be an unlucky chip.
 
Ah yes the CPU PLL is at 1.85V.... wasn't sure if i should knock that up any more than 0.05V because I couldn't find safe limits for that anywhere so didn't want to risk it! would you happen to know what your's is at?

Does anyone know the danger with changing the base clock? cause to me it seems that would give me the best change in clock speed.
 
Have a look here for overclocking help up to 4.5GHz on a Gigabyte board.

That PLL voltage sounds about right, just don't push it over 1.9V

I doubt you'll be able to change base clock much anyway, you could try pushing it up to 100.5MHz like how they did in the overclocking guide
 
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OK I've got it to 4.54GHz by pushing the base clock to 101MHz, multiplier to 45x and changed a couple of other settings, seems to be running stable for the moment. Will stress and leave for a couple of hours while i go out then maybe knock up the multiplier some more, see if i can coax any more out of it. I think the problem was me not having the System Agent voltage put up at all (now at 1.135V)!

Thanks for your help :D
 
Do you not have "PLL OVERVOLTAGE" in the "Advanced CPU Core section"? Maybe a bios update is needed to show it. This is the function that gives you 3 to 5 times more multi's. Obviously Vcore might need to be raised but this setting should help you overclock better.
 
I do indeed have that enabled yes.

It crashed while i was out :( sad times.

Pretty sure that is all i have left to try unless there is anything else to try! Don't know what settings i haven't tried if not. Back to 4.4GHz then. Thanks for you help everyone!
 
The newer 2500Ks don't overclock as well as the older ones. Mine sturggles with 4.5GHz and there's many other people with newer chips with similar struggles. Those voltages are high for a 4.4 OC but it may be the best your chip can deliver.
 
Yeah i know the voltages are high, i could probably lower them down a bit now that i'm not trying to push it anymore. Got the chip 6 days ago so yes pretty new. Kind of disappointed but still happy with 4.4GHz :p
 
have you tried offset voltage rather than fixed voltage? I couldn't get my chip stable over 4.5GHz with a fixed voltage but I have it stable at 4.7GHz using offset voltages. just trying to see how low I can take the offset now.
 
^

same, with manual voltage mine wouldn't load into windows even at 1.38-1.39v for 4.7ghz

using the offset i got into windows but failed prime after 10mins at 1.36v
 
Are you guys just overclocking for the sake of it or is there some decent reason for doing so.

Coming from my e2180 at 3.2 my i5-2500k blows it away at stock and its not like its being maxed in games.

I bought my e2180 with the intention of overclocking it from day 1 to get decent performance but think i'll leave the i5 until it needs it.
 
Rather than start my own very similar thread, I thought I might aswell join this one. I'm pretty much in the same boat , just trying to OC for the experience since I have none and to see what my 2500k can do, even though I can just set it to auto OC on my board.

I am having some trouble though. I'm using the asrock z68 extreme4 and whenever I attempt to manually OC and boot into windows, the clock is applied for about a second or two after starting a prime95 torture test, but then it lowers itself back down to around 3.8Ghz (from 4.4-4.8 depending on what I set the multi). What might be causing this?

Also, while waiting for an answer on that I decided to try to lower the voltages as much as I could with the Auto 4.8Ghz OC enabled. I set the vcore to a fixed 1.35 in the bios, but running prime95 after starting up I saw that the Vcore was at 1.256, which I thought was odd, although I was thinknig this might be vdroop? (I don't know)

prime.jpg


However the confusing thing is now I have stopped prime95, and the CPU is running a much lower clock, the voltage has RISEN to 1.352v. Ehh??
 
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However the confusing thing is now I have stopped prime95, and the CPU is running a much lower clock, the voltage has RISEN to 1.352v. Ehh??
Click to expand...

This is my understanding from my previous research, hopefully someone will confirm it:

That's because that's the fixed voltage. That's the voltage it's aiming for the whole time but the more the CPU's working the more Vdroop there is pulling the vcore down.

Do you not have speedstep enabled - the clock looks the same?
 
Nah, speedstep is enabled, that was just an error on my end with the second screenshot, but it was way down to 1.6Ghz but at around 1.35V. Its not really a problem, but just something I find odd. Any idea on the first problem; why my manual OC runs for about 1-2s in Prime95 then the multi lowers itself to ~38?
 
Sampsy said:
Nah, speedstep is enabled, that was just an error on my end with the second screenshot, but it was way down to 1.6Ghz but at around 1.35V. Its not really a problem, but just something I find odd. Any idea on the first problem; why my manual OC runs for about 1-2s in Prime95 then the multi lowers itself to ~38?
Click to expand...

Ah I see lol you can change it by using offset voltages to overclock instead, if you don't like the idea of your voltages being that high constantly, that's what I do and when running Prime95 (@4.7GHz) my voltages are around 1.37V but idling my voltages sit at around 1.010V.

As for the other problem I'm not too sure buddy, haven't come accross that one yet...:confused:
 
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