Need help : Z68XP-UD7 and I-2600K : overclock wall at 4.8 Ghz

[Saldo]

This my first post here.
I know my way around with OC flightsim computers and recently upgraded my system.

Hardware :
I7-2600K
z68XP-UD7
8Gb G.Skill Ripjaws 2133 mhz with fanmodule
Gigabyte GTX580 SO
OCZ 1000W psu
1x  OCZ   60 Gb SSD sata 3
3x  OCZ 120 Gb SSD sata 3
Thermaltake Kandalf case with factory built in liquid cooling system

My former setup with a I7-860 processor ran at 4.25 Ghz with memory 1800 mhz 9/9/911 @ 1600 mhz 6/6/6/25
Before the UD7 I owned a Ud-4 for a couple of days but was able to return it and buy a UD-7.
Just to be sure I had the best hardware I could get.

The issue is that I hit a wall at 4.8Ghz.
Up to 4.8 Ghz oc is very easy.
I need to run the cpu V at 1.465, cpu pll at 1.86, memory at 1.56. Memory at Extreme/Expert and Loadline at Level 5.

I tried to set the BLCK to 1020 and even 1040. With cpu at 1.5, memory at 1.6 and Loadline at Lvele 6 it boots into Windows , but the system is not stable enough to run Games.
I tried with memory at 1866 mhz and even 1600 mhz , but no luck.

Of coarse the cpu can has a limit . but I want ot be sure if there are no settings that I did not think af that can make a difference.
Because of the liquid cooling system the cpu temperature never goes over 50 degrees Celcius.

All suggestions are welcome.

[Aussie Allan]

    Welcome  Saldo

     Sadly....some chips just never get to where we want them to get..... many factors come into to play.........

  Like you .... I have a Thermaltake Kandalf LCS case but the factory cooling setup went loooooooooong ago!

  the overall case design is well thought out and carries quite a reasonable build quality .... but the factory cooling leaves a lot to be desired

  The RAD is now ancient in efficiency compared to what you can buy off the shelf today...... and the hoses have only a 6mm bore (double the bore size from 6mm to 12mm has a theoretical flow-rate increase of 8 times of the original size....Fact!)

  The pumps andreservoirs will fail you eventually.......I went through 3 pumps and a cracked reservoir (yes , very lucky)  in 14 months before I said enough is enough.

  If your handy........ I took to my case with Jigsaw and dremel and installed a "X-Changer 360 RAD" with 12.7mm barbs (half inch) and never looked back

  Now that's out of the way ..... I suspect your problem is Memory........try this..........8GB G.Skill Dual Channel kit, DDR3-2133 RipjawsX Series with active cooling fan. For the Intel Sandy Bridge platform. PC3-17000 2133MHz with timings of 9-11-9-28 (CL9). 1.65V dual channel kit (2x4GB), 240 pins. Equipped with new style red RipjawsX Series heatsinks.......

                                                                VERY  IMPORTANT!

  Check and check again,...... make sure your QPI/VTT is within .5V of the Memory voltage......less than is fine .....more than can damage the onboard CPU memory controller / memory ... or both .... for best result, set all voltage and timings manually (NO XMP)

  Aussie Allan

[Saldo]

Thanks for helping me.

My Kandalf LCS is running perfectly since 3 yers now and I never had any issues.
Lucky me  

Regarding the oc :
I crancked up the CPU Vcore to 1,505 , Loadline 6 , QPI/Vtt to 1,14, PCH Core to 1,12 , CPU Pll to 1,88 and DRam Voltage to 1,64.
With a BLCK at 1020 and Cpu Ratio at 49 I am now running at  4.95 Ghz.
I have top admit that I had to set the memory back to 1866 mhz, but a Sandybridge does not take very much advantage over 1600 mhz.

If the system stays stable over the next couple of days I will try to back up a little on some settings.

It is a pity that the Dram voltage on manual only has 1.64 or 1.66 and not 1.65.
Would you think that setting the memory to 1.66 sould be to much ?

[Aussie Allan]

Thanks for helping me.

My Kandalf LCS is running perfectly since 3 yers now and I never had any issues.
Lucky me   .......you know what's gunna happen now you said lucky me this system was really designed for a heat loading of about 75-100Watts

Regarding the oc :
I crancked up the CPU Vcore to 1,505 , Loadline 6 , QPI/Vtt to 1,14, PCH Core to 1,12 , CPU Pll to 1,88 and DRam Voltage to 1,64.
With a BLCK at 1020 and Cpu Ratio at 49 I am now running at  4.95 Ghz........ keep a handy eye out for BSOD codes if they happen.....really helpful from here on in
I have top admit that I had to set the memory back to 1866 mhz, but a Sandybridge does not take very much advantage over 1600 mhz................ Figured as much.....tighter timings are waaaaaaaaaaay  much better then raw MHZ re performance

If the system stays stable over the next couple of days I will try to back up a little on some settings................... 1.505 is pressing the envelope....even on water......what's the core temp at this voltage idle and load

It is a pity that the Dram voltage on manual only has 1.64 or 1.66 and not 1.65.
Would you think that setting the memory to 1.66 sould be to much ?..... Not at all as you have a dedicated fan to help the heat generated Ive seen memory that required 1.7v before running stable.....remember to keep the Memory voltage and QPI/VTT Ratio going if you raise the memory Volts

...........See Above.......... Aussie Allan

[Dark Mantis]

Just to answer your last point there as long as you have decent cooling and keep the temperature down and you make sure that the QPI/Vtt voltage always stays within 0.5v of the memory voltage it doesn't really matter what voltage you use. You could take it up to 1.75v as long as the QPI/Vtt was at least 1.25v minimum. You might have a problem with the heat though!

PLEASE NOTE I AM NOT RECOMMENDING DOING THIS AS A NORM 

[Saldo]

Up to now I tried till 1.68v for memory .
Windows is booting but than hanging.

Perhaps it is the CPU.

[Aussie Allan]

 Try raising QPI/VTT a notch or two.......better yet have a read through this.....might give you some clues

  http://www.overclock.net/intel-cpus/538439-guide-overclocking-core-i7-920-930-a.html

  Aussie allan

[Dark Mantis]

It might just be that you have reached the limit of what your hardware will run at. 

[Saldo]

At this moment I have the system running at 5 Ghz without freezes.
I have to do some Flightsimulator benchmarktests first.
( A short one I did and no freezes or whatsoever )
 

However , I want to aks you guys what you think about the values from 5Ghz compared to 4.8 Ghz:

4.8Ghz
Loadline Level 5
Vcore 1.47
QPI/Vtt  1.1
System Agent 0.935
PCh Core 1.1
CPU Pll 1.86
VDram 1.6
Memory 2133 mhz auto settings
CPU temp 40-54 C  

5 Ghz
Loadline level 8
Vcore 1.505
QPI/Vtt 1.2
System Agent 0.945
CPU pll  1.88
VDram  1.7
Memory 1866 mhz auto settings
CPU temp   53-67 C

[Aussie Allan]

  Ben

   Your starting to enter the area of diminishing returns  .... if those are load temps.....Good!.....if there idle.....Huston! "we have a problem"

  what are the timings of the memory at 1600 and 2133 respectively...... this could be the deciding factor....memory speed,and timings can have a huge impact on real world usage.........raw speed is not everything, but data through-put is

 the Volts (Vcore) at 1.505v is pretty well the limit before damage can start to degrade the CPU....... even at 1.450 ... longevity will be cropped regardless you're on water........but who knows........we could be talking about going from 5 yrs down to 3yrs, ....no one really knows!

  bar the Vcore.....everything else looks Hunk i-dorie...... Welcome to the 5Gig hz Club.....I take it you liked those tutes I sent over

  Anyway early days.....youve only been at it .....what 3 to 4 hrs on the clocking.......some people take months.

  Aussie Allan

[Saldo]

Today I got an issue.

Yesterday I did Flightsimulator at 5 Ghz and everything went perfect.
This morning I booted the pc and in the Bios I set everything back to the settings when I was running at 4.8 ghz

After rebooting all seemd fine, but after firing up FSx I got a blue screen with the 101 error.
I tried some small changes but no luck.

So I set the Vcore in steps from 1.465 till 1.48.
With 1.48 Fsx boots and is running.
Two days ago I could run this at 1.465.

What is your advise on this ?