Need help configuring Intel DZ68DB for i5 2500k OC

Hello guys,

I have never overclocked, but ever since I discovered Folding@Home I decided to overclock my Core i5 2500k to squeeze extra folding out of it. I followed some core i5 OC'ing guides without success. Here's a summary of my situation:

What I want: Cores work at 4.7 Ghz or so all the time while folding.

What actually happens: Cores crank up to a x39 multiplier in the first minute or so of folding, then go back to x33 and stay there indefinitely. After messing with the mobo's settings the Core will stay at x16 rather than x33 -.-. This also happens with Prime95 testing.

Help me solve this conundrum and I will gladly change my folding team to Tom's Hardware. thumb.gif

My Setup:
Core i5 2500k
Cooler Master Hyper 212 Plus heatsink
ECS GeForce GTX 560
Intel DZ68DB motherboard with latest BIOS
Corsair 500W Builder Series V2 PSU

I use CPUID 1.59 to monitor the current multiplier, and PC Wizard 2010 to monitor temperatures and core activity.

Overclocking guides I saw tell me to put the QPI ratio at lowest and disable things such as Spread Spectrum, C1E Support, Limit CPUID Max, EIST, and Intel Speedstep, while enabling Load-line Calibration, Intel PLL Overvoltage and Intel Turbo Boost. However, out of all these options I only managed to find and disable Processor C-states, Speedstep and Turbo Boost, and if I try to disable Speedstep it tells me I must have it enabled for the Turbo Boost technology to work and thereby be able to change the max multiplier.

Here's my current settings in the "Processor overrrides" section:

CPU Voltage Override Type: Dynamic (can choose Static or None, I tried putting it static at 1.350V but this is causing the processor to work at x16 rather than x33 as mentioned above)
Processor Core Voltage Offset: 0.000

Max non-turbo Ratio: 33 (if I change this, it reverts back to 33 automatically)
Processor Idle State: High-Performance

Turbo Boost: Enabled (must do so to be able to change multipliers):
TDC current limit overrride (Amps): 97
- Burst Mode Power Limit (Watts): 150
Sustained Mode Time (seconds): 32 (this is the maximum value it allowed me)
Sustained Mode Power Limit (Watts): 150
IGD Current Limit (Amps): 32

Active Core-based Ratio Limits: Disable (while disabled it applies the multiplier I choose to all cores; when enabled I can choose separate multipliers for each core.)
Ratio Limit: 47

I have not messed with the Amps values, only Watts (they were originally somewhat lower than 150).

The "Burst Mode" and "Sustained Mode" are described in the BIOS as temporary states. Is there no way to make the Turbo multiplier work all the time? It certainly should, since folding uses all cores at 100% all the time.

Thanks!

I was having the exact same issues you were/are having, until I figured out the Intel DZ68DB (*bios ver.0032) just isn't built for hardcore overclocking. In fact, your options are highly limited. Basically, this board will limit your overclock by "turning off" turbo boost when the CPU exceeds a certain current/heat level. I'm not sure what causes this and I would love to find a solution... But, as far as I can tell, there is only really one effective way to push K series i5's and i7's through the 4ghz barrier with this board; You have to find the maximum possible clock multiplier, using the smallest amount of voltage, without hitting the current limit that causes turbo boost to cut out in things like Prime 95.

Prep 1: When setting the voltage override for the CPU in the bios, forget about using the normal or dynamic setting. Intel has intentionally gimped the power so that when using any K series Sandy Bridge, you will only be able get about 3.7ghz "permanent" turbo boost on all 4 cores when using normal or dynamic voltage. Lame huh? You have to use a "static" voltage for this to work.

Prep 2: Download Prime 95 and CPU-Z if you don't already have them. It's also helpful to have a CPU temperature monitor up. Run Prime95 for at least 15 to 30 minutes to make sure you have a reliable clock, preferably longer "hours".

To make things simple, set it so the turbo boost multiplier is the same no matter how many cores are being utilized. Start with a 1.3v static voltage. Then, set your turbo boost to something like 3.8ghz. Use the torture tests in Prime 95 to push all 4 cores to 100%, then monitor the turbo boost speed using CPU-Z. You can see the clock rates for all 4 cores by right clicking on the Intel logo. If you see it drop to the default clock rate, then you are using too much current. Go back to the bios and set the static voltage one notch down. Repeat the monitoring process with Prime95 / CPU-Z until it never drops to the default clock rate. Then, go back to the bios and set your turbo boost multiplier up a notch on all 4 cores. Repeat the monitoring process. If you see it go back to default clock rate, go back to the bios and drop the static voltage. Keep doing this until you see a blue screen or Prime95 fails a test, then back down on the turbo boost multiplier or up the voltage a notch.

Your mileage will vary of course, but hopefully you can get it stable at 4.1~4.2ghz or higher. I eventually hit a sweet spot at 4.2ghz turbo boost on all 4 cores and 1.175v static voltage in the bios. When running Prime95, CPU-Z reports the voltage to be 1.216v. My temps range from 80ºF (idle) to 126ºF (4X100%). As I said earlier, the limiting factor with this board seems to be the total amount of current passing through the CPU. If someone could figure out how to disable the "current limit/turbo boost cut off", I bet you could easily hit 5ghz with this board...

*If you have a bios version older then 0032, it's OK to flash it to that version. However, DO NOT flash to version 0040! That version will potentially kill your board / cripple your overclocking options. In fact, if you aren't having any issues with USB or whatnot, don't flash at all... This board doesn't take kindly to being flashed.

Hey garrigotti, the problem with the DZ68DB is most of the overclocking options seen in other boards simply aren't there. About the only thing you can adjust is the turbo boost multi and the cpu voltage. For example, this is what my bios looks like:

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CPU Voltage Override Type: <Static> "None, Dynamic, and Static are your options"
Processor Voltage Override: <1.1750V> "In Dynamic mode, you can increase voltage from default by 0.05v increments, but not decrease it. "

Maximum Non-Turbo Ratio: 34

Processor Idle State <Low Power> "Changing it to high performance SAYS it locks turbo boost, but nothing happens"

Intel Turbo Boost Technology: <Enable>

TDC Current Limit Override (AMPS): 255 "Changing this doesn't seem to do anything, from 80 to 255 the results are the same"
Burst Mode Power Limit (Watts): 118 "You can't change this, even though it looks like you can."
Sustained Mode Time (Seconds): <1> "Makes no difference since this board forces you to use static voltage to OC"
Sustained Mode Power Limit (Watts): 95 "You can't change this, even though it looks like you can."
IGD Current Limit: 30 "irrelevant, I don't use integrated graphics"

Active Core-Based Ratio Limits: <Enable>
4-core ratio limit: 42 "35 is stock for 2550K"
3-core ratio limit: 43 "36 is stock for 2550K"
2-core ratio limit: 44 "37 is stock for 2550K"
1-core ratio limit: 45 "38 is stock for 2550K"

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As you can see, to say options are limited on this board would be a gross understatement. Considering that and the super low current limit it allows you for turbo boost... You can only overclock by reducing a static voltage and praying that your CPU overclocks good at laptop like voltages. LOL I'm amazed I got mine running at the above ratios, actually.

Now, if someone could figure out how to disable the "current limit", "turbo boost max energy usage detector", "Intel's secret hidden ninja that hates overclocking", or whatever you want to call it... Then we would be on to something. You could get over 5ghz I bet. But until someone figures that out, then this board just isn't going to OC much better then the situation I described above.

Yes, but unfortunately the DZ68DB isn't supported. I tried anyway, but when you attempt to run the software, it hangs.

I explained above. 0040 is the "newest" BIOS, but it breaks the motherboard:

http://intel-openport.hosted.jives [...] age/154429
http://communities.intel.com/thread/28767

Furthermore, I've seen lots of people straight up paper weighting the DZ68DB when they flash, ending with them having to get a RMA. 0032 seems to be the most choice version for this board, so until someone can say FOR CERTAIN that another version is an improvement... Then I'm not going to risk it.


Edit: I think I've reached the best possible "all the time" turbo boost OC on this board. Like I said several times, there is a current limit. You can see it. You can measure it. It's there, but there is no option that changes it. No BIOS version magically unlocks it like a ASUS or GIGABYTE motherboard. At far as I know, no one who owns this board has circumvented this. In fact, I DARE someone to prove me wrong with screens of higher clock rates on their DZ68DB... LOL I Dare you!