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Xeon E5-1680 v2 overclocking

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Here I have a Xeon E5-1680 v2 (which is an Ivy Bridge-EP processor). Since it has an open multiplier, I'm overclocking it. Currently I'm using it on an Asrock Rack EPC602D8A mainboard - yes, there are Xeon mainboards with overclocking capabilities.


As a start, I set the all-core turbo multiplier to 40 so that it should run with 4 GHz on all of its eight cores. In heavy tests like Prime95, it will however clock down to 3700-3800 MHz. The reason is that the CPU won't go over its rated TDP of 130 W. Hwinfo64 and HWMonitor confirm that. I've changed quite some BIOS settings, including the short and long duration power limits, but these values got ignored by the CPU.

Also the high performance power plan in Windows 7 doesn't change the problem besides running the CPU at 4 GHz in idle while still downclocking it on high load.


The temperature isn't a problem because the internal temperature sensors report about 65 °C maximum for the hottest core: it is really the power limit which is holding back the CPU.

My question is: do I really have to get a used X79 mainboard to ignore the CPU's TDP? Or is this a restriction of the Xeons which even X79 mainboards cannot ignore?

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  • 1 month later...



I had a look at the OC section of the Asrock Rack EPC602D8A manual. The board does offer complete controls of the parameters. As the temperatures were correct, the only explanation for your problem I can think of is that the system is not accepting the saved configuration:


Page 40 (English)


3.3.4 Saving Current Settings as User Defaults

In this option, you are allowed to load and save three user defaults according to your own



Save 1st User Default

Type the name and press [ENTER] to save the changes as the 1st User Default.


Save 2nd User Default

Type the name and press [ENTER] to save the changes as the 2nd User Default.


Save 3rd User Default

Type the name and press [ENTER] to save the changes as the 3rd User Default.


If the configurations were not saved, the system may revert back to the default settings when restarted.


If the ASRock BIOS tuning is not effective: As an experiment, consider trying Intel Extreme Tuning Utility. It is not as refined a solution as there may be some controls: overriding the duration of running over 130W that are not available.


However, XTU was effective on the E5-1680 v2 in an HP z620 workstation that does not offer any native tuning control. I am running the E5-1680 v2 on all cores at 4.1GHz with only slightly elevated temperatures. In Passmark Performance test, the single-thread rating is 2020 at the default settings, but at 4.1GHz all cores it is 2252. ETU can saved multiple profiles also and my plan is to have a 3D modeling profile with as high a one- core setting as possible (4.3GHz?) and the other cores can run at 3.3 or 3.4.


Of course, a careful control of voltages and timings could yield higher clock speeds. The E5-1680 v2 is quoted as running at 4.3GHz, but in my uses, which includes CPU rendering, I don't want any possibility of instability. A single thread rating of 2200 is enough. I may try having one core @4.2 and run the others at 3.7GHz- that kind of thing, but I am quite nervous to simply try higher settings until failure. The problem is that XTU is zu einfach- too easy!


I'm using XTU also on an HP z420 E5-1660 v2 @ 4.2 on one core and 4.0 on the other five +1.625Mv and the Passmark single thread rating is 2324. Ausgezeichnet,..


I would be interested to know how you progress. What is your use of the system?






HP z620_2 (2017): Xeon E5-1680 v2 (8-core@ 4.1GHz) / 64GB DDR3-1866 ECC registered / Quadro P2000 5GB / HP Z Turbo Drive M.2 256GB (Samsung SM951) + Intel 730 480GB + 2X Seagate Constellation ES.3 1TB / ASUS Essence STX sound card / 800W PSU > Windows 7 Prof'l 64-bit > 2X Dell Ultrasharp 27" (2560 X 1440)


Architecture / Industrial Design /Graphic Design

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  • 3 weeks later...

Sorry for my late response, I moved to a new apartment during the last weeks and so everything was a bit chaotic.


I installed XTU on the system and is behaving a bit weird. Here is a screenshot first:



With this setting, everything is at "Auto" in the BIOS. I set a multiplier of 38 in XTU and started the stress test. As you can see in the graph at the bottom, the CPU still runs at only 3.4 GHz. Maybe this has something to do with the issue that XTU seems to only detect 6 cores instead of 8, according to the screenshot. When I let AIDA64 show the CPU turbo settings, I can confirm that XTU is only setting the turbo multiplier of core 1 to 6 to x38, but for core 7 and 8 it is x34 - this is the reason for the 3.4 GHz.




Concerning this weird behaviour with XTU, I decided to NOT trust this tool. Quite funny that a tool created by Intel doesn't know how many cores their own CPUs have...


In addition, now the mainboard won't even run stable with the settings which were completely stable some weeks before.


During the next days I will try another mainboard (Asus P9X79 Pro) which I got some days ago. I will post my results here.

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  • 1 month later...
  • 3 weeks later...

Hi BlackArchon,


With regards to overclocking, COOLING IS EVERYTHING.


I have a HP Z620 with E5-1680 v2 running at 4.7GHz.




In Passmark 9;




And Passmark 8;




Single threaded score for PM8 is 2565.


I've attached some images of the cooling arrangement.


I also have a water cooled GTX 1080Ti and a Quadro P2000 in my system, 64GB 1866MHz DDR3 and 256GB Samsung SM951 (AHCI) boot drive.

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Thank you for the pictures! I have also thought about getting water cooling for the chip, but this would also mean I need a new mainboard. Currently the be quiet! Dark Rock TF is cooling the CPU and the VRMs surrounding the socket. The air cooler is directly blowing air over the VRM coolers and they still get so hot that I can't touch them for more than even a second. This means that their surface temperature is about 40 to 50 °C. If I would use water cooling, than there wouldn't be any direct air flow over the VRMs and I would probably get massive VRM throtteling. And yeah... I don't think it is wise to invest about 400 € into a used Rampage Extreme or a similar board with a beefier VRM solution.

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