New OC on 2500k, voltage anomaly

[UnknownXV]

Hi,

 

So far I've been quite happy with my overclocking luck. I'm on a 2500k. A week ago I had an issue with my CPU underclocking itself after I tried to OC it, but I fixed it by flashing the bios (as recommended here). After which, I was able to reach 3.8 ghz without touching the voltage at all. I changed the multiplier only, and it worked fine. Easy OC.

 

Two days ago I increased it again to 4.2 ghz, and this time I manually set the voltage to 1.255 in the bios. However, in CPU-Z, it displays 1.2 at idle, and between 1.13 and 1.15 under full load. Load voltages are essentially at stock speeds.

 

Shockingly enough, it seems stable (5 hours in Prime95 and 2 days of gaming so far without issues) even at this much lower voltage level. Does anyone know what is causing the voltages to drop? Should I disable energy saving states and what not? 

 

Also, about the likes of Turbo boost, speedstep, and the aforementioned C1, C3, C6, etc.. energy saving states. I've googled them, but I've seen conflicting results as to what is best to leave on and off for a stable OC. I do not care at all about energy saving. It's a minor electrical cost since we're only dealing with the cpu. 

 

Also, side question, is this a good sign that I have a decent chip? I've heard it takes more than stock voltages to get past 4 ghz with a 2500k. Oh and one more thing, I've heard that downclocking your RAM a bit can help reach a higher OC on your cpu. Is this true?

 

On a final note, temperatures are looking great so far. The hottest core gets to 55 celcius, coolest one is at 49 under full load (after 5 hours). This is with an ambient temperature of 27 celcius, so the delta at worse is 28. 

 

System:

 

Intel 2500k @ 4.2 ghz cooled by a Swiftech H220

ASrock Extreme 3 Gen 3 motherboard (latest bios)

16 GB corsair vengeance ram running at 1,333 mhz (downclocked from 1,600 mhz for easier CPU OC)

2 OCZ Solid 3 SSDs in raid 0

GTX 770 (factory oc)

Corsair AX860i platinum PSU

 

On windows 7 home 64-bit

 

Thanks for any advice. :)

[Wats]

The voltage drop is called Vdroop. You can fight Vdroop with Load line calibration (LLC). Even though current and past Intel chips actually are fine with a bit of Vdroop, it's only useful for those "offset overclocks" (ex: 1.6GHz and .8v, 'Turboing' to 4.6 and 1.28v). The Vdroop helps in that case by allowing the voltage for single threaded apps to be higher (say, 1.3v) but then lowering to a more sane and (should be) stable 1.28v when under 100% load.

 

 

For 'fixed' voltages, you will want some LLC. On Asrock boards, I think 1 is the highest amount, and 5 is the lowest. Manually set LLC to about 3 or 4 and test.

[UnknownXV]

I'm confused, shouldn't the cpu require more voltage at 100% load to be stable? 

[KneesWeak]

CPUZ ISN'T ACCURATE WITH VOLTAGES.  Take third part programs like cpuz lightly.  Great program but its hard to actively read voltages going to the cpu while in windows with anything, the bios is the only thing you can trust (mostly).  Im running a 6300 @4.65 at 1.475 volts and cpuz reads it at 1.126 or something (it fluctuates) and the stock voltage is 1.3.  My case may be more extreme but voltage throttling detected by cpuz shouldnt worry you unless its affecting your temps wildly or clockspeed.

[Wats]

I'm confused, shouldn't the cpu require more voltage at 100% load to be stable? 

Yeah.

 

Just enable and increase Load Line Calibration, that'll cut down on the voltage drop you're having. Did I explain it really poorly? :s

 

 

CPUZ ISN'T ACCURATE WITH VOLTAGES.  Take third part programs like cpuz lightly.  Great program but its hard to actively read voltages going to the cpu while in windows with anything, the bios is the only thing you can trust (mostly).  Im running a 6300 @4.65 at 1.475 volts and cpuz reads it at 1.126 or something (it fluctuates) and the stock voltage is 1.3.  My case may be more extreme but voltage throttling detected by cpuz shouldnt worry you unless its affecting your temps wildly or clockspeed.

You're absolutely correct.

 

With op's extreme3, I'll bet the reading is quite wrong.

[UnknownXV]

Why would the motherboard make CPU-Z's reading more inaccurate? 

[KneesWeak]

Why would the motherboard make CPU-Z's reading more inaccurate?

What? its not the motherboard its the task the program is trying to accomplish.  

[UnknownXV]

I was referencing to Wat's statement

 

"With op's extreme3, I'll bet the reading is quite wrong."

 

 

Why would my motherboard, the Asrock extreme3 gen3 motherboard affect the cpu-z readings?

[Ddm5]

I was referencing to Wat's statement

 

"With op's extreme3, I'll bet the reading is quite wrong."

 

 

Why would my motherboard, the Asrock extreme3 gen3 motherboard affect the cpu-z readings?

Quality of the motherboards themselves?, I've never had a problem with reading the voltage off of my Formula V.

[leipero]

Don't worry about it, as long as system is stable. I set manually voltage to 1.275v (on AMD CPU), on 100% load it drops to 1.248 according to both the CPU-Z and AIDA64. Those readings are most probably accurate.

[UnknownXV]

Extremely, ridiculously good news so far.

 

I've reached 5 GHZ!!!

 

And more importantly, the voltages are SO low. I used offset voltage + 0.055 which puts it, under load, at between 1.3 and 1.33, which evidently is quite low for a 5 ghz OC. Maybe I can go even higher?

 

Hottest core temp so far is 67 celcius after 30 minutes of intel utility stress test. Will report more on that after a few hours of testing to ensure stability.

 

Damn this is awesome. 

[MichalCZE97]

Extremely, ridiculously good news so far.

 

I've reached 5 GHZ!!!

 

And more importantly, the voltages are SO low. I used offset voltage + 0.055 which puts it, under load, at between 1.3 and 1.33, which evidently is quite low for a 5 ghz OC. Maybe I can go even higher?

 

Hottest core temp so far is 67 celcius after 30 minutes of intel utility stress test. Will report more on that after a few hours of testing to ensure stability.

 

Damn this is awesome. 

Nice! You've got really lucky in sillicon lottery I guess. I'm pretty sure you would be able to hit 5.2 GHz. Also post what score will you get in Cinebench just for reference.

 

Edit: Just checked Youtube and I found some videoes of people hitting 5.5 Ghz or even above, so you could probably push it very far. Good luck! :)

[UnknownXV]

Yep certainly. 

 

Although to get it stable in prime95 and longer in intel utility test I had to increase the voltage to 1.37 or so. Still, pretty happy. I'm not sure I want to go much higher though, the temperatures are still below 70 degrees even after an hour under full load, but even if temperatures don't go too high, I'm still playing with high voltages. I want my CPU to last another year at least, so I don't think I will go higher.

 

When I started to OC I didn't intend to go beyond 4.4 ghz, so I'm pretty damn happy. I was able to hit 4.4 ghz basically on stock voltage. 

 

Heres' the cinebench and cpu-z stuff. 

 

http://valid.canardpc.com/2863587

 

[MichalCZE97]

Yep certainly. 

 

Although to get it stable in prime95 and longer in intel utility test I had to increase the voltage to 1.37 or so. Still, pretty happy. I'm not sure I want to go much higher though, the temperatures are still below 70 degrees even after an hour under full load, but even if temperatures don't go too high, I'm still playing with high voltages. I want my CPU to last another year at least, so I don't think I will go higher.

 

When I started to OC I didn't intend to go beyond 4.4 ghz, so I'm pretty damn happy. I was able to hit 4.4 ghz basically on stock voltage. 

 

Heres' the cinebench and cpu-z stuff. 

Nice chip. I envy you now. :P

If you don't want to go higher you don't have to, of course. Overclock only as much as you feel comfortable. For that reason I didn't push my GPU any further I wasn't happy with the temperatures getting over 80°C so have gone lower instead to get 75°C at maximum load, which I'm happy with. Also as Linus said, it's technically not possible to end sentence with „with“, but I just did. :D

[sonarctica]

This thread has made me wanna OC my CPU more than 5GHz.... 55C on load and voltages aren't too high either so I should be well off