Overclocking 2500K on AsRock Fatal1ty Z68 Gen 3 - Quite confused

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DMFD-Minister

Limp Gawd
Joined
Jan 14, 2008
Messages
416
I'm pretty confused at the moment, so hoping there is an easy setting somewhere to disable. I'm also not super experienced with overclocking, I dabbled around with it on a 955 and I have read plenty of guides, but I would rate my level of experience as novice (trying to learn).

So I have the following config:

Asrock Z68 Fatal1ty Gen 3
Intel 2500K
8GB G. Skill Sniper 1.25v
1050W Ultra X4 PSU

Everything is under water. Stock idle temps for 2500k are between 25 and 29 Celsius depending on the core. Currently with Prime 95 running, I'm seeing load temps between 45 and 50 Celsius depending on the core. I am using CPU-Z and AIDA64 to monitor my system.

My issue is this:
I'm trying to achieve 5.0Ghz+ overclock. I figured I'd shoot for 4.8 first. I'm able to boot into windows at a number of various voltages, but finally have settled on 1.375 or 1.385. My issue is that whenever I test prime95, I go from 1600mhz to 4790mhz and then the CPU starts throttling. It'll drop the vCore to 1.29 and my multiplier to 42/43. It's literally bouncing all over the place and I don't understand it. Raising the voltages hasn't stabilized it thus far, and I can't really find anyone else experiencing the same thing.

I'm beginning to wonder if "Turbo" is kicking in somewhere and screwing things up. I like the idea of the processor being all efficient and whatnot, just want it running at 4800Mhz when it's in use.

Can anyone shed light on this? Let me know if I can provide any additional detail.
 
And strangely enough, as soon as I stopped prime, it jumped to 4790Mhz/1.384 vCore and jumps back and forth between that and 1596Mhz (spending about 90% of the time at 4790. What the world?

Same thing happens on AIDA64 stress test. As soon as I start maxing out the CPU, it drops to x42/43 multiplier and 1.29 vcore. It seems to bounce around looking for an optimal range for a while until settling in around x42/43
 
Did you disable Intel(R) Turbo Boost Tech and CPU Enhanced Halt (C1E)/Speedstep in the BIOS?
 
with my i5 2500k I have it @ 4.1ghz 1.300v While my turbo mulitiplier reads a steady 41 I have noticed that the vcore drops to about 1.246 when under 100 percent load and idles at 1.294. Not sure what is causing my drops under load.
 
DMFD-Minister said:
And strangely enough, as soon as I stopped prime, it jumped to 4790Mhz/1.384 vCore and jumps back and forth between that and 1596Mhz (spending about 90% of the time at 4790. What the world?

Same thing happens on AIDA64 stress test. As soon as I start maxing out the CPU, it drops to x42/43 multiplier and 1.29 vcore. It seems to bounce around looking for an optimal range for a while until settling in around x42/43
Click to expand...

The jumps back and forth between 1600 and 4800 are just the idle powersaving features kicking in (C1E and EIST). You can disable them if you want, but normally there is no reason to, and I don't think they are causing you 42/43 issue. Neither of those is standard turbo multipliers, so it really doesn't make sense that it would be dropping to those unless it is throttling (which seems unlikely at those temps). I seem to recall someone else having similar issues here recently, but I can't remember the resolution, if there was one. I'll see if I can dig up the link.

Edit: Here it is, a BIOS update fixed it for him. Did you try upping the setting for CPU wattage (or whatever it is called - normally is expressed in the BIOS as a percentage - so going from 100% to 120% or something)?
http://hardforum.com/showthread.php?t=1652671&highlight=throttling

Stanfiem said:
with my i5 2500k I have it @ 4.1ghz 1.300v While my turbo mulitiplier reads a steady 41 I have noticed that the vcore drops to about 1.246 when under 100 percent load and idles at 1.294. Not sure what is causing my drops under load.
Click to expand...

The voltage drop is just Vdroop, and is normal under load. Increasing the setting for Load Line Calibration will help offset the drop.
 
How you changed power limits in UEFI ? It normally is 150 which might be not enough for such high OC. Try setting them to 200-250.
 
Forceman said:
I'll see if I can dig up the link.

Edit: Here it is, a BIOS update fixed it for him. Did you try upping the setting for CPU wattage (or whatever it is called - normally is expressed in the BIOS as a percentage - so going from 100% to 120% or something)?
http://hardforum.com/showthread.php?t=1652671&highlight=throttling



The voltage drop is just Vdroop, and is normal under load. Increasing the setting for Load Line Calibration will help offset the drop.
Click to expand...

Thanks for the link. I'll try a different BIOS revision and will also attempt to up the Wattage limits in the BIOS to see what happens when I get home from work today. It makes sense that it would likely be some sort of wattage/power setting since it only throttles the overclock under 100% load

Love all the people in the post you linked saying the motherboard the guy had is crap without even knowing anything about it. I'm not even sure he identified what it was, lol. I'm going to ignore them for now :)
 
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I had that wierd multi drop issue where mine went to 4.2ghz and soon as I stopped the prime test it shot up to the 4.5ghz setting I had it at. I ended up doing a battery pull on the CMOS and starting over with my settings and the issue went away. Was really odd. I would start by getting the latest BIOS but keep in mind you might want to do a battery pull on it or CMOS jumper.. Stupid Gigabyte Board I was using didnt have a CMOS Clear jumper. I would try to disable the Turbo and see if that changes anything also.
 
Here's something I found. This is unique to AsRock UEFI I believe as far as I can tell. When you enable manual multiplier control, you still have to set the short and long duration turbo voltage limits which control exactly how much power you can run through the CPU. I raised mine to 125/110 and it seemed to fix the issue for 4.8Ghz.

Overclocking proved to be slightly more challenging than we’d anticipated. This was partly down to familiarity – this was our first time with an ASRock EFI – but the board had some idiosyncrasies too.

When we tried our first overclock, for example, we were bemused to see the clock speed jumping all over the place in Windows. A little investigation found that this was because we’d left the Turbo Boost power limit (the maximum Wattage that the CPU can draw when Turbo Boosting) settings in the EFI at their default options.

In our experience, these settings are usually overridden when you change the core voltage options, but this wasn’t the case with the P67 Extreme4. Still, it was easy to fix, and simply required us to raise the short and long duration power limits to 300W, and also increase the core current limit to 300W. The 300W value we used was merely an arbitrarily high value.
Click to expand...
http://www.bit-tech.net/hardware/mot...eme-4-review/7

Edit:
Also worthy of note is my significant voltage drop under load. This turned out to be a little setting called "CPU Load-Line Calibration" which is designed to increase voltages when more power is needed, but does not help very much when you're trying to do a significant overclock. The AsRock Z68 Fatal1ty Gen3 board has 6 settings: Auto, Line 1, Line 2, Line 3, Line 4, and Line 5. Line 1 means there is no adjustment while Line 5 is the most significant adjustment. Setting CPU Load Line Calibration to Line 2 has stabilized my voltages.
 
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Dang...I just passed 3dMark Vantage at 5.2Ghz with CPU set to 1.425v in UEFI and reading 1.44-1.45 in CPU-Z under load. Max temps on CPU 68C.

I'm going to bring it back down to 4.5ish now :)

Also had 5Ghz stable Prime 95 at 1.39v with CPU Load Level 2.
 
So do BIOS settings work right with this MB? I'm thinking about getting one if it works.

How does it do with over clocking memory?
 
SonDa5 said:
So do BIOS settings work right with this MB? I'm thinking about getting one if it works.

How does it do with over clocking memory?
Click to expand...

Yes, the settings work correctly if you know which ones you're supposed to adjust. I haven't overclocked memory because I could probably invest energy elsewhere and realize bigger gains, but the menu for overclocking memory has a plethora of options. I could try to scan the BIOS manual sometime if that would be helpful?
 
DMFD-Minister said:
Dang...I just passed 3dMark Vantage at 5.2Ghz with CPU set to 1.425v in UEFI and reading 1.44-1.45 in CPU-Z under load. Max temps on CPU 68C.

I'm going to bring it back down to 4.5ish now :)

Also had 5Ghz stable Prime 95 at 1.39v with CPU Load Level 2.
Click to expand...

How long on Prime and did you try Intel burn in?
 
DMFD-Minister said:
Yes, the settings work correctly if you know which ones you're supposed to adjust. I haven't overclocked memory because I could probably invest energy elsewhere and realize bigger gains, but the menu for overclocking memory has a plethora of options. I could try to scan the BIOS manual sometime if that would be helpful?
Click to expand...


When you make a change in the bios settings for speed or voltage does the change happen?
 
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