i5 2500k: Possible to just increase multiplier to overclock to 4,2 ghz?

[Ourgas2 3]

Hi all,Some advice on overclocking my i5 2500k now at 3,3 ghz. (With turbo boost reaching 3,6 -3,7 ghz).M/B: Gigabyte Z68X-UD3P-B3RAM: 8 gb.G/C: Nvidia GeForce GTX 560 Ti.I want to overclock my CPU moderately to reach about 4,2 ghz.The question is if I can just increase the multiplier without touching anything else such as voltage. I don't know how risky this is.Will my M/B be able to handle this?Will it be stable or overheat? (CPU cooler is a regular one).Also, based on somebody's experience, will 4,2 ghz make a difference with my current CPU speed?Thanks,Christos

[dazz 69]

Christos, you'll need to test it yourself.If you up your multi to 42 and leave the Vcore alone (set to Auto) your board will overvolt to adjust to the new clock speed.Do you have a decent aftermarket cooler installed or is it the stock heatsink?You sould stress test on stock clocks with Prime95 or OCCT for example, and monitor your temps with Core Temp or Real Temp to see if you really have good enough temps to overclock.If you don't have an aftermarket cooler you probably won't. Max temp at full load in the hottest core is 8oºC, so if you are not at least below 70ºC don't even try overclocking.If your temps are ok, once you up your multi stress test again and check your Vcore with CPU-Z. If it's below 1.38V you should be ok (again tempos should stay below 8oºC at full load once overclocked)

Edited January 4, 2012 by dazz

[Ourgas2 3]

Hi dazz and thanks for your detailed answer.Some facts about which you wrote:Temperatures (according to Core Temp) are from 66 to 72 degrees.However, CPU-Z (under SPD section, which I am not sure it this is Vcore voltage) shows 1,5 - 1,5 - 1,5 and 1,650.Workable?Thanks,Christos

[dazz 69]

Hi dazz and thanks for your detailed answer.Some facts about which you wrote:Temperatures (according to Core Temp) are from 66 to 72 degrees.However, CPU-Z (under SPD section, which I am not sure it this is Vcore voltage) shows 1,5 - 1,5 - 1,5 and 1,650.Workable?Thanks,Christos

Vcore in CPU-Z is "Core Voltage" in the "CPU" tab.Are those full load temps?

[Ourgas2 3]

Vcore is 1,056 V but not full load I guess.How can I full load it to test it?ThanksChristos

[dazz 69]

Christos, you'll need to test it yourself.If you up your multi to 42 and leave the Vcore alone (set to Auto) your board will overvolt to adjust to the new clock speed.Do you have a decent aftermarket cooler installed or is it the stock heatsink?You sould stress test on stock clocks with Prime95 or OCCT for example, and monitor your temps with Core Temp or Real Temp to see if you really have good enough temps to overclock.If you don't have an aftermarket cooler you probably won't. Max temp at full load in the hottest core is 8oºC, so if you are not at least below 70ºC don't even try overclocking.If your temps are ok, once you up your multi stress test again and check your Vcore with CPU-Z. If it's below 1.38V you should be ok (again tempos should stay below 8oºC at full load once overclocked)

:smile:That is idle Vcore. It will go up at full load.If those temps are not full load temps, I'm not sure I would even try stress testing. What are your idle temps like? Edited January 4, 2012 by dazz

[Jude Bradley 659]

Short reply... Yes.

[Techinica 0]

My i5 2500k went straight to 4.5Ghz with only multipliers... needed a little more juice to get it to 5.0Ghz though. Rock solid there too. Cooled on air with NH-D14.

[MrKen 3]

I'll agree for the most part with what's already been posted.If you leave vcore on auto, then you can adjust the multi to your heart's content because it will automatically rise to the occasion.HOWEVER, auto vcore is extremely high on sandy bridge CPUs and will (in oc situations) always go higher than it needs and typically high enough to degrade your CPU over time. Google electromigration.As long as your cooler is decent (not necessarily the best available), set vcore manually to 1.3 or 1.35. The 4 sandy bridge CPUs I've tested would all do 4.3GHz on less than that & the 2600k I'm on right now will run 4.8 at 1.35v. Check temps during an hour or so of prime95 & if it stays tolerable you'll have a long lasting fsx monster. (I say 1 hour because you're only looking for temps at full load, not testing for CPU stability)

[Ourgas2 3]

To you guys who overclocked it to 4,2 or 4,5 (from standard 3,3).Did you see a noticeable difference in fsx performance?Thanks,Christos

[BryanB 0]

I got my i5 to 4.7ghz by just adjusting the multiplier. I have an A70 corsair cooler too

Edited January 11, 2012 by BryanB

[Turbine777 13]

Did you see a noticeable difference in fsx performance?

Yes, you will see a very noticeable difference in such a leap, but head to the advice of Dario and Ken. Be sure also to take what others say about their overclocks with a grain of salt though. One builder could have taken higher precautions and better building practices than another. Also know that TIM and coolers make a lot of difference. Just applying thermal compound incorrectly can cause major instability. Dario has the best advice, especially in saying "you'll need to test it yourself". In other words, again, take what others say always that they may know more than is being mentioned. You'll save a lot of hardware that way and frustrations. Doing like Dario stated with slowly raising your clock and thoroughly testing is also something that can't be stressed enough. Today's boards are much more forgiving than those of us old timers that risked frying everything with any small adjustment we made, but blindly pushing it based off anyone elses settings is still not the proper way to do it, or learn for that matter. That will just leave you looking for answers later rather than learning what overclocking is.Make small adjustments and thoroughly test with Prime95 just like Dario stated. If all you use it for is FSX and you only test your stability with FSX, then you can be going down a very bad road. My overclock is quite weak and for FSX I can get a very stable 4.2 from my 2.6, however, my sim time is 1/1000th of what I do with my comp and that OC causes too many issues with After Effects rendering and most of my video codecs. All of which I expect issues from after running Prime95.

[divermar 1]

My i5 2500k went straight to 4.5Ghz with only multipliers... needed a little more juice to get it to 5.0Ghz though. Rock solid there too.Cooled on air with NH-D14.

I'm about to setup a new i5, can you tell me what settings you used? I have the Asus P8Z68 Delux/Gen3 and it will be water cooled. I do enjoy testing different configs but sometimes its better to ask and go from there, I have seen many sites that show the 4.5Ghz but I'm interested in the 5.0Ghz or more.Thanks in advance